This file was created by the TYPO3 extension publications --- Timezone: CEST Creation date: 2026-06-03 Creation time: 09:49:23 --- Number of references 72 article Stranghoener2020 The potential for the mobilization of Fe from secondary phases within subsurface basaltic rocks of the Hawaii Scientific Drilling Project Phase2 (HSDP2) drill core was investigated to elucidate the possible contribution of volcanic islands to the Fe budget of nearby ocean surface waters. Rock specific parameters governing Fe mobilization, such as Fe redox state, specific surface area (SSA), and connected porosity were determined. A four-step sequential extraction procedure using solutions with increasing strength of the extractants was applied to characterize different states of chemical bonding of Fe in secondary phases of the basaltic rocks, a controlling parameter for its release to oceanic water. The sequential extraction results were then used as a measure for the reactivity of secondary Fe-bearing phases and the mobilizable Fe from these rocks. Basaltic rocks with different degrees of weathering showed elevated Fe(III) contents up to 58% total Fe as Fe(III), compared to 11–18% in fresh basalts. SSAs increased with depth, with maximum values of 70 m2/g observed for hyaloclastites. Both parameters depended mainly on the alteration state of the basalt, which was more strongly affected by the fluid chemistry (freshwater ↔ seawater) than by the age of the rocks. The sequential extractions revealed the presence of highly reactive secondary Fe-bearing phases in submarine rocks exposed to seawater whereas observations for rocks altered in freshwater point to better crystallized phases with lower mobilizable Fe contents. In seawater, aging of secondary Fe-bearing phases was most probably suppressed by the adsorption of silica and multivalent anions. Comparing different types of rock, hyaloclastites and pillow basalts showed the highest mobilizable Fe with up to 19% and 16%, respectively, of the total Fe of the bulk rock. The potential for high amounts of mobilizable Fe from basaltic rocks altered under seawater dominated conditions suggests that the submarine part of volcanic ocean islands represent an underestimated source of Fe supply to ocean surface waters. © 2020 Elsevier Ltd 2020 English 08832927 10.1016/j.apgeochem.2020.104705 Applied Geochemistry 121 Elsevier Ltd Institute of Mineralogy, Leibniz Universität Hannover, Callinstr. 3, Hannover, 30167, Germany; Institute of Soil Science, Leibniz Universität Hannover, Herrenhäuser Str. 2, Hannover, 30419, Germany; Geomicrobiology, Federal Institute for Geosciences and Natural Resources, Stilleweg 2, Hannover, 30655, Germany Basalt; Budget control; Chemical bonds; Core drilling; Extraction; Infill drilling; Positive ions; Seawater; Silica; Submarines; Surface waters; Volcanoes; Weathering, Chemical bondings; Controlling parameters; Scientific drilling; Secondary phasis; Sequential extraction; Sequential extraction procedure; Specific surface area (SSA); Volcanic ocean island, Iron compounds, adsorption; basalt; chemical bonding; mobilization; seawater; sequential extraction; silica; surface water; volcanic island, Hawaii https://www.scopus.com/inward/record.uri?eid=2-s2.0-85089266795&doi=10.1016%2fj.apgeochem.2020.104705&partnerID=40&md5=29128762b3e411d9dcde53f2204f9f15 cited By 1 M. Stranghoener S. Dultz H. Behrens A. Schippers article Pierdominici2020 Knowledge of the in situ stress state of the Earth's crust plays a key role in understanding geological processes including plate tectonics, earthquakes, slope failure, and igneous emplacement. In this paper, we determine the in situ stress orientation from the PTA2 borehole on the island of Hawai'i, drilled into a lava flow dominated sequence between Mauna Kea and Mauna Loa. High-resolution acoustic images were collected from the open hole interval 886 m to 1,567 m. Based on identification of 371 borehole breakouts for a total length of 310 m, the mean orientation of the minimum horizontal principal stress is N106° and remains constant across different volcanic rock fabrics. Changes in borehole breakout shape are linked to the different strength of volcanic facies and intra-facies. The orientation of the present-day stress field at Mauna Kea deviates from the plate forces and regional tectonic stress field. We interpret the compressive stress regime at the PTA2 site as resulting from the competing gravitational fields of the large topographic highs of Mauna Kea and Mauna Loa. Our study reveals that the mass accumulation associated with shield volcano growth imparts significant local variations to the subsurface stress state on volcanic islands consisting of overlapping shield volcanoes. The results have significant implications for stress accumulation leading to brittle failure and flank collapse, along with potentially influencing magma accumulation and ascent pathways during volcanic island evolution. This study provides the first insights into the orientation of the present-day stress field between the major island forming shield volcanoes of Hawai'i. ©2020. The Authors. Article 2020 English 21699313 10.1029/2020JB019768 Journal of Geophysical Research: Solid Earth 125 Blackwell Publishing Ltd 8 Hawaii [(ISL) Hawaiian Islands]; Hawaii [United States]; Hawaiian Islands; Mauna Kea; Mauna Loa; borehole breakout; in situ stress; lava flow; shield volcano; stress field; volcanic island https://www.scopus.com/inward/record.uri?eid=2-s2.0-85089831311&doi=10.1029%2f2020JB019768&partnerID=40&md5=d8e21ec53f3ba5c08effa092746604e2 Cited by: 2; All Open Access, Green Open Access, Hybrid Gold Open Access John M. Millett Jochem K. M. Kück Donald Thomas Dougal A. Jerram Sverre Planke Eric Haskins Nicole Lautze Olivier Galland article Jerram201915 To help understand volcanic facies in the subsurface, data sets that enable detailed comparisons between down-hole geophysical data and cored volcanic intervals are critical. However, in many cases, the collection of extended core intervals within volcanic sequences is rare and often incomplete due to challenging coring conditions. In this contribution we outline and provide initial results from borehole logging operations within two fully cored lava-dominated borehole sequences, PTA2 and KMA1, on the Big Island of Hawai`i. Data for spectral gamma, magnetic susceptibility, dipmeter resistivity, sonic, total magnetic field, temperature and televiewer wireline logs were successfully acquired for the open hole interval ca. 889 m to 1567 m within the PTA2 borehole. Spectral gamma was also collected from inside the casing of both wells, extending the coverage for PTA2 to the surface and covering the interval from ca. 300 to 1200 m for KMA1. High-quality core material was available for both boreholes with almost complete recovery which enabled high-resolution core-to-log integration. Gamma data are generally low commonly in the range ca. 7-20 gAPI but are shown to increase up to API of ca. 60 with some intrusions and with increases in hawaiite compositions in the upper part of PTA2. Velocity data are more variable due to alteration within porous volcanic facies than with burial depth, with a general degrease down-hole. The high-resolution televiewer data have been compared directly to the core, enabling a comprehensive analysis of the variations in the televiewer responses. This has enabled the identification of key features including individual vesicles, vesicle segregations, strained vesicles, chilled margins, rubble zones, intrusive contacts and pāhoehoe lobe morphologies, which can be confidently matched between the televiewer data and the full diameter core. The data set and results of this study include findings which should enable improved borehole facies analysis through volcanic sequences in the future, especially where down-borehole data and images but no core are available. © Author(s) 2019. 2019 English 18168957 10.5194/sd-25-15-2019 Scientific Drilling 25 Copernicus GmbH 15-33 CEED, University of Oslo, Oslo, Norway; DougalEARTH, Solihull, United Kingdom; VBPR - Volcanic Basin Petroleum Research, Oslo, Norway; Department of Geology and Petroleum Geology, University of Aberdeen, Aberdeen, United Kingdom; Helmholtz-Zentrum Potsdam, Deutsches GeoForschungsZentrum, Potsdam, Germany; University of Hawai'i at Hilo, 200 W. Kawili St., Hilo, HI 96720-4091, United States; Hawaii Groundwater and Geothermal Resources Center, University of Hawai'i at Manoa, 1680 East West Road, Honolulu, HI 96822, United States; Earth, Environmental and Biological Sciences, Queensland University of Technology, Brisbane, QLD, Australia Coremaking; Image enhancement; Magnetic susceptibility; Thermal logging; Volcanoes, Borehole logging; Comprehensive analysis; Facies analysis; Full diameter core; Geophysical data; High resolution; Volcanic facies; Wireline logging, Boreholes https://www.scopus.com/inward/record.uri?eid=2-s2.0-85067228279&doi=10.5194%2fsd-25-15-2019&partnerID=40&md5=27c65b145c196ae40cda7d0d26191bbe cited By 17 D.A. Jerram J.M. Millett D. Thomas S. Planke E. Haskins N. Lautze S. Pierdominici article Stranghoener2018 The interaction of a single bacterial species (Burkholderia fungorum) with basaltic rocks from the ICDP HSDP2 drill core and synthetic basaltic glasses was investigated in batch laboratory experiments to better understand the role of microbial activity on rock alteration and Fe mobilization. Incubation experiments were performed with drill core basaltic rock samples to investigate differences in the solution chemistry during biotic and abiotic alteration. Additionally, colonization experiments with synthetic basaltic glasses of different Fe redox states and residual stresses were performed to evaluate their influence on microbial activity and surface attachment of cells. In biotic incubation experiments bacterial growth was observed and the release of Fe and other major elements from drill core basaltic rocks to solution exceeded that of abiotic controls only when the rock sample assay was nutrient depleted. The concentration of dissolved major elements in solution in biotic colonization experiments with synthetic basaltic glasses increased with increasing residual stress and Fe(II) content. Furthermore, the concentration of dissolved Fe and Al increased similarly in biotic colonization experiments indicating that their dissolution might be triggered by microbial activity. Surface morphology imaging by SEM revealed that cells on basaltic rocks in incubation experiments were most abundant on the glass and surfaces with high roughness and almost absent on minerals. In colonization experiments, basaltic glasses with residual stress and high Fe(II) content were intensely covered with a cellular biofilm. In contrast, glasses with high Fe(III) content and no residual stress were sparsely colonized. We therefore conclude that structurally bound Fe is most probably used by B. fungorum as a nutrient. Furthermore, we assume that microbial activity overall increased rock dissolution as soon as the environment becomes nutrient depleted. Our results show that besides compositional effects, other factors such as redox state and residual stress can control microbial alteration of basaltic glasses. © 2018 Stranghoener, Schippers, Dultz and Behrens. 2018 English 1664302X 10.3389/fmicb.2018.01252 Frontiers in Microbiology 9 Frontiers Media S.A. Institute of Mineralogy, Leibniz Universität Hannover, Hanover, Germany; Geomicrobiology, Federal Institute for Geosciences and Natural Resources, Hanover, Germany; Institute of Soil Science, Leibniz Universität Hannover, Hanover, Germany JUN glass, abiotic stress; Article; bacterial growth; biotic stress; chemical analysis; glucose intake; Gram negative bacterium; Hawaii; incubation time; microbial activity; microbial colonization; microbial growth; organismal interaction; pH; scanning electron microscopy https://www.scopus.com/inward/record.uri?eid=2-s2.0-85048595587&doi=10.3389%2ffmicb.2018.01252&partnerID=40&md5=b607429350a3cf0aec45533efbb92808 cited By 13 M. Stranghoener A. Schippers S. Dultz H. Behrens article Cai20178664 In this study, we collected samples from subaerial basaltic glassy margins from the second Hawaii Scientific Drilling Project (HSDP2) core. We employed the rigorous “IZZI” method during the paleointensity experiment combined with the stringent “CCRIT” criteria for data selection to obtain 21 robust paleointensity estimates recorded by glassy margins from 20 lava flows. We compared our new results to published paleointensities from the interiors of the lava flows from HSDP2 and found that our data are systematically lower than those from the interiors of the same lava flows. The reasons for the discrepancy in intensity are still unclear, but one possibility that could not be absolutely excluded is the effect of cooling rate on the more slowly cooled lava flow interiors. Although our new data from the glassy margins are lower than those from the lava flow interiors, they are still overall higher than the expected field of the study site calculated from a geocentric axial dipole model with an ancient average field of 42 ZAm2, either because of a long-term local anomaly of the field in Hawaii or an insufficient age distribution of our new data (e.g., missing the time period with low field intensities). ©2017. American Geophysical Union. All Rights Reserved. Article 2017 English 21699313 10.1002/2017JB014683 Journal of Geophysical Research: Solid Earth 122 Blackwell Publishing Ltd 8664 – 8674 11 Hawaii [United States]; United States; basalt; drilling; glass; lava flow https://www.scopus.com/inward/record.uri?eid=2-s2.0-85033592177&doi=10.1002%2f2017JB014683&partnerID=40&md5=bed9bb5f35b83bbca8909bfa2ab56a88 Cited by: 7; All Open Access, Bronze Open Access, Green Open Access S. Cai L. Tauxe G. Cromwell article Brounce20178997 The behavior of C, H, and S in the solid Earth depends on their oxidation states, which are related to oxygen fugacity (fO2). Volcanic degassing is a source of these elements to Earth’s surface; therefore, variations in mantle fO2 may influence the fO2 at Earth’s surface. However, degassing can impact magmatic fO2 before or during eruption, potentially obscuring relationships between the fO2 of the solid Earth and of emitted gases and their impact on surface fO2. We show that low-pressure degassing resulted in reduction of the fO2 of Mauna Kea magmas by more than an order of magnitude. The least degassed magmas from Mauna Kea are more oxidized than midocean ridge basalt (MORB) magmas, suggesting that the upper mantle sources of Hawaiian magmas have higher fO2 than MORB sources. One explanation for this difference is recycling of material from the oxidized surface to the deep mantle, which is then returned to the surface as a component of buoyant plumes. It has been proposed that a decreasing pressure of volcanic eruptions led to the oxygenation of the atmosphere. Extension of our findings via modeling of degassing trends suggests that a decrease in eruption pressure would not produce this effect. If degassing of basalts were responsible for the rise in oxygen, it requires that Archean magmas had at least two orders of magnitude lower fO2 than modern magmas. Estimates of fO2 of Archean magmas are not this low, arguing for alternative explanations for the oxygenation of the atmosphere. © 2017, National Academy of Sciences. All rights reserved. 2017 English 00278424 10.1073/pnas.1619527114 Proceedings of the National Academy of Sciences of the United States of America 114 National Academy of Sciences 8997-9002 Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, United States; Department of Earth Sciences, University of California, Riverside, CA 92521, United States 34 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85027855971&doi=10.1073%2fpnas.1619527114&partnerID=40&md5=67d568a9d044f7bfcc2a02f11c1573d1 cited By 88 M. Brounce E. Stolper J. Eiler article Huang2016182 Geochemical analyses of stratigraphic sequences of lava flows are necessary to understand how a volcano works. Typically one sample from each lava flow is collected and studied with the assumption that this sample is representative of the flow composition. This assumption may not be valid. The thickness of flows ranges from &lt;1 to &gt;100 m. Geochemical heterogeneity in thin flows may be created by interaction with the surficial environment whereas magmatic processes occurring during emplacement may create geochemical heterogeneities in thick flows. The Hawaii Scientific Drilling Project (HSDP) cored ∼3.3 km of basalt erupted at Mauna Kea Volcano. In order to determine geochemical heterogeneities in a flow, multiple samples from four thick (9.3–98.4 m) HSDP flow units were analyzed for major and trace elements. We found that major element abundances in three submarine flow units are controlled by the varying proportion of olivine, the primary phenocryst phase in these samples. Post-magmatic alteration of a subaerial flow led to loss of SiO2, CaO, Na2O, K2O and P2O5, and as a consequence, contents of immobile elements, such as Fe2O3 and Al2O3, increase. The mobility of SiO2 is important because Mauma Kea shield lavas divide into two groups that differ in SiO2 content. Post-magmatic mobility of SiO2 adds complexity to determining if these groups reflect differences in source or process. The most mobile elements during post-magmatic subaerial and submarine alteration are K and Rb, and Ba, Sr and U were also mobile, but their abundances are not highly correlated with K and Rb. The Ba/Th ratio has been used to document an important role for a plagioclase-rich source component for basalt from the Galapagos, Iceland and Hawaii. Although Ba/Th is anomalously high in Hawaiian basalt, variation in Ba abundance within a single flow shows that it is not a reliable indicator of a deep source component. In contrast, ratios involving elements that are typically immobile, such as La/Nb, La/Th, Nb/Th, Ce/Pb, Sr/Nd, La/Sm, Sm/Yb, Nb/Zr, Nb/Y and La/Yb, are uniform within the units, and they can be used to constrain petrogenetic processes. Nevertheless all elements are mobile under some conditions. For example, a surprising result is that relative to other samples, the uppermost sample collected from subaerial flow Unit 70, less than 1 m below the flow surface, is depleted in P, HREE and Y relative to all other samples from this flow unit. This result is complementary to the P, REE and Y enrichment found in subaerial lava flows from several Hawaiian shields, e.g., Kahoolawe and Koolau Volcanoes. These enrichments require mobilization of REE and followed by deposition a P-rich mineral. © 2016 Elsevier Ltd Article 2016 English 00167037 10.1016/j.gca.2016.01.015 Geochimica et Cosmochimica Acta 185 Elsevier Ltd 182-197 Department of Geoscience, University of Nevada, Las Vegas, United States; Department of Geosciences, University of Massachusetts Amherst, United States; Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, United States; School of Earth and Space Sciences, University of Science and Technology of China, China chemical composition; core analysis; element mobility; enrichment; igneous geochemistry; lava flow; sequence stratigraphy; shield volcano; trace element; volcanic rock, Hawaii [(ISL) Hawaiian Islands]; Hawaii [United States]; Hawaiian Islands; Mauna Kea https://www.scopus.com/inward/record.uri?eid=2-s2.0-84958576544&doi=10.1016%2fj.gca.2016.01.015&partnerID=40&md5=2b0512f6e7e083113ffe1015fcd726be cited By 6 S. Huang M.J. Vollinger F.A. Frey J.M. Rhodes Q. Zhang article Dultz201671 For an understanding of the effect of solution composition on the dissolution rate of basaltic glass detailed knowledge of surface chemistry is important. Here the zeta potential (ζ) as a characteristic parameter of the magnitude of surface charge at the solid-liquid interface was used to determine ionic effects on surface chemistry in initial stages of basaltic glass dissolution. In a systematic approach powdered synthetic basaltic glass was dispersed in solutions of different cations (NO3- salts of Na+, K+, Mg2+, Ca2+, Ba2+, Zn2+, and Al3+) and anions (Na+ salts of F-, Cl-, I-, NO3-, SO42-, C2O42-, HPO42-), each in concentrations of 0.1, 0.5, 1.0, 2.5, and 5.0 mmol/L. ζ was traced in time sequences up to 12,000 h at ideally circumneutral pH. Ion affinities to glass surfaces were characterized by sorption isotherms. A change of glass chemical composition by the formation of altered layers was determined by depth profiling using secondary neutral mass spectrometry (SNMS). The dissolution of the glass was quantified by the amount of Si released after 4000 h.A marked decrease of ζ in deionized water within the first 3 h reaction time is assigned to the desorption of alkali and alkaline earth metal cations from the glass surface and formation of negatively charged SiO- sites. The addition of anions resulted in stronger negative initial ζ values in comparison with the experiment in deionized H2O indicating marked anion adsorption on surface sites, most obvious for F-, C2O42- and HPO42-. The initial ζ was increased upon the addition of divalent cations indicating neutralization of negatively charged surface sites. Over time a striking shift from negative to positive ζ was obtained, most markedly for Ca2+ and Zn2+. The addition of trivalent Al3+ resulted directly in positive ζ indicating a strong adsorption on glass surfaces. With the progress of the experiment the sign of ζ reversed to negative values again. The reason for charge reversal is not fully understood and might be related with cation adsorption exceeding the negative surface charge and a concentration of Fe oxides at the glass surface. After an ~2000 h reaction time ζ adjusted for most electrolyte additions to slightly negative ζ until the end of the experiment, indicating that a final state in the composition of surface sites was reached. The presence of monovalent Na+ and K+ in solution suppressed Si release from the glass, whereas it is accelerated by bivalent cations. It appears that the neutralization of deprotonated ≡Si-O- sites by monovalent cations - their preferential binding is also indicated by chemical analysis - favors polymerization resulting in slower Si release. Upon the addition of Al3+ it is likely that ≡Si-O-Al-O-Si≡ bonds are formed, which can suppress Si release. The presence of F-, C2O42-, and HPO42- clearly enhances glass dissolution, most probably by increasing the coordination of network forming cations, hereby weakening bonds. The observed generation of positive ζ on basaltic glass surfaces is remarkable, and can improve in natural systems the adsorption capability of the basaltic glass surface for negatively charged compounds from pore solution, anions, dissolved organic matter and also bacterial cell walls. © 2016 Elsevier B.V. 2016 English 00092541 10.1016/j.chemgeo.2016.01.027 Chemical Geology 426 Elsevier 71-84 Institute of Mineralogy, Leibniz Universität Hannover, Callinstr. 3, Hannover, D-30167, Germany; Institute of Non-Metallic Materials, Clausthal University of Technology, Zehntnerstraße 2a, Clausthal-Zellerfeld, D-38678, Germany Adsorption; Alkalinity; Aluminum; Basalt; Binding sites; Biological materials; Calcium; Cell membranes; Chemical analysis; Deionized water; Depth profiling; Dissolution; Electrolytes; Geochemistry; Ions; Mass spectrometry; Negative ions; Phase interfaces; Positive ions; Salts; Silicon; Surface chemistry; Zeta potential; Zinc, Alkaline Earth metal cations; Basaltic glass; Charge reversal; Dissolved organic matters; Electrolyte effect; Negative surface charges; Negatively charged surfaces; Secondary neutral mass spectrometry, Glass, concentration (composition); dissolution; electrolyte; experimental study; igneous geochemistry; silicon, Bacteria (microorganisms) https://www.scopus.com/inward/record.uri?eid=2-s2.0-84957899504&doi=10.1016%2fj.chemgeo.2016.01.027&partnerID=40&md5=aedb041748dc45d30eb524e65b457794 cited By 9 S. Dultz H. Behrens G. Helsch J. Deubener article 10.1130/GES00935.1 {Recent ocean-bottom geophysical surveys, dredging, and dives, which complement surface data and scientific drilling at the Island of Hawaii, document that evolutionary stages during volcano growth are more diverse than previously described. Based on combining available composition, isotopic age, and geologically constrained volume data for each of the component volcanoes, this overview provides the first integrated models for overall growth of any Hawaiian island. In contrast to prior morphologic models for volcano evolution (preshield, shield, postshield), growth increasingly can be tracked by age and volume (magma supply), defining waxing alkalic, sustained tholeiitic, and waning alkalic stages. Data and estimates for individual volcanoes are used to model changing magma supply during successive compositional stages, to place limits on volcano life spans, and to interpret composite assembly of the island. Volcano volumes vary by an order of magnitude; peak magma supply also varies sizably among edifices but is challenging to quantify because of uncertainty about volcano life spans. Three alternative models are compared: (1) near-constant volcano propagation, (2) near-equal volcano durations, (3) high peak-tholeiite magma supply. These models define inconsistencies with prior geodynamic models, indicate that composite growth at Hawaii peaked ca. 800–400 ka, and demonstrate a lower current rate. Recent age determinations for Kilauea and Kohala define a volcano propagation rate of 8.6 cm/yr that yields plausible inception ages for other volcanoes of the Kea trend. In contrast, a similar propagation rate for the less-constrained Loa trend would require inception of Loihi Seamount in the future and ages that become implausibly large for the older volcanoes. An alternative rate of 10.6 cm/yr for Loa-trend volcanoes is reasonably consistent with ages and volcano spacing, but younger Loa volcanoes are offset from the Kea trend in age-distance plots. Variable magma flux at the Island of Hawaii, and longer-term growth of the Hawaiian chain as discrete islands rather than a continuous ridge, may record pulsed magma flow in the hotspot/plume source.} 2013 10 1553-040X 10.1130/GES00935.1 Geosphere 9 1348-1383 5 https://doi.org/10.1130/GES00935.1 Peter W. Lipman Andrew T. Calvert article NobreSilva2013659 The 3500 m deep Hawai'i Scientific Drilling Project core provides a ~680 kyr record of the magmatic history and source components of Mauna Kea volcano. We report high-precision Pb-Sr-Nd isotopic compositions of 40 basalts from the last 408 m of the final drilling phase (HSDP2-B and HSDP2-C) and show that these lowermost basalts represent the early shield stage of Mauna Kea's growth history. Two sample groups are distinguished based on their isotopic variability compared to the rest of the core. Over a depth interval of 210 m (3098.2-3308.2 mbsl), the basalts show very restricted isotopic variation and represent sampling of a relatively homogeneous source. Samples from the bottom 192 m record the largest range of 206Pb/204Pb and 208Pb/204Pb in the core, reflecting the greater isotopic variability of the earlier stages of volcanism compared to subsequent stages. The heterogeneity of Mauna Kea lavas is explained by mixing variable proportions of four distinct components intrinsic to the Hawaiian mantle plume. One of these components, Kea, is a prevalent and long-lived composition within the Hawaiian plume, whereas the other three components are involved at different stages of the volcano's history and contribute to the short-term isotopic variability of Mauna Kea. The compositional similarity of the Kea component to "C" and to the super-chondritic bulk-silicate Earth suggests that Kea may be part of the primitive mantle of a non-chondritic Earth. Other Pacific oceanic island basalts share Kea-like compositions, indicating that the Kea component is a common, widespread composition within the Pacific deep mantle. ©2013. American Geophysical Union. All Rights Reserved. Article 2013 English 15252027 10.1002/ggge.20047 Geochemistry, Geophysics, Geosystems 14 Blackwell Publishing Ltd 659 – 676 3 Hawaii [(ISL) Hawaiian Islands]; Hawaii [United States]; Hawaiian Islands; Mauna Kea; Pacific Ocean; United States; Basalt; Core samples; Lead; Silicates; Strontium; Thermal plumes; Volcanoes; HSDP2; Mantle heterogeneity; Mantle plume; Mauna keas; Ocean island basalts; Pb-Sr-Nd isotope systematics; isotopic composition; mantle chemistry; mantle plume; mantle source; Ocean Drilling Program; ocean island basalt; volcanism; Isotopes https://www.scopus.com/inward/record.uri?eid=2-s2.0-84879803379&doi=10.1002%2fggge.20047&partnerID=40&md5=ec636da6ec7fc641e12c50c1c39a9e9c Cited by: 29; All Open Access, Bronze Open Access, Green Open Access Inês G. Nobre Silva Dominique Weis James S. Scoates article Jourdan2012 The Hawaii Scientific Drilling Project recovered core from a 3.5 km deep hole from the flank of Mauna Kea volcano, providing a long, essentially continuous record of the volcano's physical and petrologic development that has been used to infer the chemical and physical characteristics of the Hawaiian mantle plume. Determining a precise accumulation rate via 40Ar/ 39Ar dating of the shield-stage tholeiites, which constitute 95-98% of the volcano's volume is challenging. We applied 40Ar/ 39Ar dating using laser- and furnace-heating in two laboratories (Berkeley and Curtin) to samples of two lava flows from deep in the core (∼3.3 km). All determinations yield concordant isochron ages, ranging from 612 ± 159 to 871 ± 302 ka (2σ; with P ≥ 0.90). The combined data yield an age of 681 ± 120 ka (P = 0.77) for pillow lavas near the bottom of the core. This new age, when regressed with 40Ar/39Ar isochron ages previously obtained for tholeiites higher in the core, defines a constant accumulation rate of 8.4 ± 2.6 m/ka that can be used to interpolate the ages of the tholeiites in the HSDP core with a mean uncertainty of about ±83 ka. For example at ∼3300 mbsl, the age of 664 ± 83 ka estimated from the regression diverges at the 95% confidence level from the age of 550 ka obtained from the numerical model of DePaolo and Stolper (1996). The new data have implications for the timescale of the growth of Hawaiian volcanoes, the paleomagnetic record in the core, and the dynamics of the Hawaiian mantle plume. Copyright 2012 by the American Geophysical Union. Article 2012 English 15252027 10.1029/2011GC004017 Geochemistry, Geophysics, Geosystems 13 Blackwell Publishing Ltd 5 Hawaii [(ISL) Hawaiian Islands]; Hawaii [United States]; Hawaiian Islands; Mauna Kea; United States; Infill drilling; Thermal plumes; Accumulation rates; Chemical and physical characteristics; Hawaii; Mauna keas; Ocean island basalts; Paleomagnetic record; Scientific drilling; volcanology; argon-argon dating; mantle plume; ocean island basalt; paleomagnetism; petrology; regression analysis; tholeiite; timescale; uncertainty analysis; volcanology; Volcanoes https://www.scopus.com/inward/record.uri?eid=2-s2.0-84861319786&doi=10.1029%2f2011GC004017&partnerID=40&md5=dcc57cc333cb917a5fa05a3de2738f27 Cited by: 18; All Open Access, Bronze Open Access, Green Open Access Fred Jourdan Warren D. Sharp Paul R. Renne article Rhodes2012 [1] The final Stage (Phase-2) of the Hawaii Scientific Drilling Project (HSDP) recovered 408 m of basaltic core (3098-3506 mbsl) attributed to Mauna Kea volcano. We determined the major and trace element composition of 40 samples from this core. Our results show that the incompatible element ratios, such as Zr/Nb, which are correlated with Pb isotopic ratios, are more variable in the lower 408 m of Mauna Kea shield lavas than in the overlying 2855 m (~450 ka). We argue that this geochemical diversity was present in the mantle source of Mauna Kea shield lavas and does not require the inter-fingering of lavas from adjacent volcanoes. Because of uncertainties in Ni partitioning between olivine and melt and the wide range of Ni contents in peridotites, we show that all Mauna Kea lavas may have been derived from a peridotite source. We also obtained major and trace element compositions for 24 whole-rock clasts and hyaloclastites and 7 glasses from HSDP Phase-1 core between 1767 and 1808 mbs. These enigmatic lavas, previously recognized by the distinctive high CaO and K2O contents of their glasses, are also relatively enriched in highly incompatible trace elements. We show that this group of lavas have affinities with post-shield lavas and argue that they are a consequence of lower degrees of melting (~a factor of two) than other Mauna Kea shield lavas, thereby providing evidence that magma supply varied significantly during the growth of the Mauna Kea shield. Copyright 2012 by the American Geophysical Union. Article 2012 English 15252027 10.1029/2011GC003812 Geochemistry, Geophysics, Geosystems 13 Blackwell Publishing Ltd 3 Hawaii [(ISL) Hawaiian Islands]; Hawaii [United States]; Hawaiian Islands; Mauna Kea; United States; Glass; Lead; Lithology; Olivine; Hawaiian volcanism; Hyaloclastites; Incompatible element; Isotopic ratios; Major and trace elements; Mantle plume; Mantle source; Mauna Kea; Ni content; Scientific drilling; geochemistry; isotopic ratio; lava; lead isotope; lithology; magma; mantle plume; mantle source; olivine; partitioning; peridotite; shield volcano; trace element; volcanism; Volcanoes https://www.scopus.com/inward/record.uri?eid=2-s2.0-84858957867&doi=10.1029%2f2011GC003812&partnerID=40&md5=fc7a3f26a9405d51a50abeb54a295b60 Cited by: 37; All Open Access, Bronze Open Access J. Michael Rhodes Shichun Huang Frederick A. Frey Malcolm Pringle Guangping Xu article Laj2011170 We report on new paleointensity and inclination records obtained in Hawaii from 386 samples drilled in 137 subaerial flows of the HSDP2 long basaltic core that we have combined in a composite record with the other Hawaiian results to produce a unique and accurate lava record of absolute geomagnetic field intensity and inclination at Hawaii for the last 405kyr. These data are considered together with published results from La Réunion Island, for about the same time period in order to compare them to model results. In Hawaii, when recognized excursional periods are omitted, the average VADM (VDM) value is about 8.2×(8.4)×1022Am2 and the inclination is on the average 29.8°, i.e. about 6° shallower than the expected value at this location (GAD value). In the Réunion Island, we selected published results in which both inclination and intensities values are obtained using modern methods and strict criteria. The average VADM (VDM) is 9.4±2.3 (8.7±2.3)1022Am2 and the average inclination value (when transitional data are ignored) is -44.4±2.4°, about 7° steeper than the GAD value. These results, compared with model intensities predicted by dynamo solutions that incorporate lateral variations in core-mantle boundary heat-flow derived from seismic tomography, are too high for both localities, but they decrease as the amplitude of thermal boundary anomalies increases. With strong boundary heat-flow, the model inclination anomaly at Hawaii fits with the data but at La Réunion, model inclination anomalies have the wrong sign. This comparison indicates that strong boundary heat-flow anomalies give the best fit to the data and that future improvements will be obtained by proportionally increasing both the Rayleigh number and the amplitude of heat-flow variations. © 2011 Elsevier B.V. Article 2011 English 00319201 10.1016/j.pepi.2011.05.007 Physics of the Earth and Planetary Interiors 187 170 – 187 3-4 Hawaii [United States]; United States; Calluna vulgaris; Electric generators; Seismology; Best fit; Core-mantle boundary; Expected values; Geomagnetic fields; Geomagnetic modeling; Hawaii; Heat-flow; Lateral variations; Model results; Paleointensity; Rayleigh number; Seismic tomography; Subaerial flows; Thermal boundary; Time-periods; amplitude; core-mantle boundary; geomagnetic field; heat flow; numerical model; Rayleigh number; seismic tomography; Geomagnetism https://www.scopus.com/inward/record.uri?eid=2-s2.0-80053204407&doi=10.1016%2fj.pepi.2011.05.007&partnerID=40&md5=fbc59cf74c01fd429f4b2a64b6ede82f Cited by: 13 Carlo Laj Catherine Kissel Christopher Davies David Gubbins article Weis2011831 Linear chains of volcanic ocean islands are one of the most distinctive features on our planet. The longest, the Hawaiiang-Emperor Chain, has been active for more than 80 million years, and is thought to have formed as the Pacific Plate moved across the Hawaiian mantle plume, the hottest and most productive of Earth's plumes. Volcanoes fed by the plume today form two adjacent trends, including Mauna Kea and Mauna Loa, that exhibit strikingly different geochemical characteristics. An extensive data set of isotopic analyses shows that lavas with these distinct characteristics have erupted in parallel along the Kea and Loa trends for at least 5 million years. Seismological data suggest that the Hawaiian mantle plume, when projected into the deep mantle, overlies the boundary between typical Pacific lower mantle and a sharply defined layer of apparently different material. This layer exhibits low seismic shear velocities and occurs on the Loa side of the plume. We conclude that the geochemical differences between the Kea and Loa trends reflect preferential sampling of these two distinct sources of deep mantle material. Similar indications of preferential sampling at the limit of a large anomalous low-velocity zone are found in Kerguelen and Tristan da Cunha basalts in the Indian and Atlantic oceans, respectively. We infer that the anomalous low-velocity zones at the core-mantle boundary are storing geochemical anomalies that are enriched in recycled material and sampled by strong mantle plumes. © 2011 Macmillan Publishers Limited. All rights reserved. 2011 English 17520894 10.1038/ngeo1328 Nature Geoscience 4 831-838 Department of Earth and Ocean Sciences, University of British Columbia, 6339 Stores Road, Vancouver, BC V6T1Z4, Canada; Pacific Centre for Isotopic and Geochemical Research, University of British Columbia, 6339 Stores Road, Vancouver, BC V6T1Z4, Canada; Department of Geology and Geophysics, University of Hawai'i, Honolulu, HI 96822, United States; Department of Geosciences, University of Massachusetts, Amherst, MA 01003, United States 12 asymmetry; data set; geochemical survey; isotopic analysis; mantle plume; Pacific plate; sampling; seismic velocity; volcanic island, Atlantic Ocean; French Southern Territories; Hawaiian Islands; Indian Ocean; Kerguelen; Kerguelen Islands https://www.scopus.com/inward/record.uri?eid=2-s2.0-82455210623&doi=10.1038%2fngeo1328&partnerID=40&md5=eee05ee94f6c1cccd03e46bee9b9711f cited By 180 D. Weis M.O. Garcia J.M. Rhodes M. Jellinek J.S. Scoates article Su2010873 It has long been a dream for mankind to enter the deep Earth to sample and investigate the structures and inner geological progresses. Until now, scientific drilling has been the unique method in our understanding of the processes and structures of the Earth. This paper try to give a brief introduction of the history, the development, the mission, the structure and management, the membership, the project development scheme of International Continental Drilling Program (ICDP). Great advances have been brought about in many fields of earth sciences by continental scientific drilling in recent years. Based on the recent publications and website materials of ICDP, this paper summarize the main developments in Climate Dynamics and Global Environments, in the Study of Impact Craters, in the GeoBiospherc, in Active Volcanic Systems, in Active Faults, in Hotspot Volcanoes, in Convergent Plate Boundaries and Collision Zones, and in Natural Resources. Special introduction on the scientific results of ICDP drilling at Mt. Unzen, Japan and the Hawaii Scientific Drilling Project (HSDP) is introduced in this paper. Fascinating discoveries such as the gouge layer of San Andreas Fault and the finding of talc in cuttings of SAFOD project are also introduced in this paper. As one of the three founding members of ICDP, China has also gained a lot of developments in continental scientific drilling; typical examples are the achievements of Chinese Continental Scientific Drilling (CCSD) and the progress of Lake Qinghai Scientific Drilling Project. The preliminary progresses . of the third approved ICDP project of China -the Chinese Cretaceous Continental Scientific Drilling Project and the development of ICDP-China are also summarized in this paper. Article 2010 Chinese 10009515 Acta Geologica Sinica (English Edition) 84 873 – 886 6 China; Hawaii [United States]; Japan; Kyushu; Nagasaki [Kyushu]; Qinghai; Qinghai Lake; United States; Unzen Volcano; active fault; climate change; collision zone; crater; deep drilling; hot spot; mantle plume; natural resource; San Andreas Fault; talc https://www.scopus.com/inward/record.uri?eid=2-s2.0-78649844329&partnerID=40&md5=732f4e363917ab0357a84117ef5aab8b Cited by: 9 article Farnetani2010231 A thorough understanding of the internal structure of the Hawaiian plume conduit requires to link geochemical observations of surface lavas to fluid dynamic simulations able to quantify the flow trajectories of upwelling geochemical heterogeneities and their sampling by volcanoes. With the present work we fill a gap between the numerous geochemical studies of Hawaiian lavas and the paucity of dynamical models that relate the observed geochemical record to the internal plume structure. Our three-dimensional numerical simulation of a vigorous plume sheared by a fast moving oceanic plate shows that the dominant deformation in the conduit is vertical stretching, while horizontal spreading and vertical shortening prevail in the sublithospheric part of the plume (hereafter referred to as plume head). Flow trajectories indicate that a young volcano like Loihi samples the 'upstream' side of the plume, not its center, whereas volcanoes in the post-shield phase sample deep melts from the 'downstream' side of the plume. To constrain the internal conduit structure we focus on two geochemical observations: old (>350 kyr) Mauna Kea lavas from the Hawaii Scientific Drilling Project are isotopically distinct from recent Mauna Kea lavas, but they are isotopically identical to present-day Kilauea lavas. By modelling a plume conduit with several long-lasting filaments of 10. km radius, we find that the isotopic record of a volcano (e.g., Mauna Kea) is expected to change over time-scales of ~400. kyr. Furthermore, by requiring that two age progressive volcanoes (e.g., Mauna Kea and Kilauea) sample the same filament, we constrain the minimum filament length to be ~600. km. In this paper we adopt a 'top-down' approach: from geochemical observations of surface lavas, to dynamical models of the conduit structure, and further down to the 'geochemical architecture' of the thermal boundary layer feeding the plume. A conduit structure with filaments maps back into heterogeneous volumes with azimuthal and radial extents of several hundred kilometers in the source region of plumes. © 2010 Elsevier B.V. Article 2010 English 0012821X 10.1016/j.epsl.2010.04.005 Earth and Planetary Science Letters 295 231 – 240 1-2 Hawaii [United States]; United States; Computer simulation; Filaments (lamp); Conduit structure; Dynamical model; Fluid dynamic simulation; Geochemical heterogeneity; Internal structure; Isotopic record; Kilauea; Long lasting; Mantle heterogeneity; Oceanic plate; Phase samples; Plume dynamics; Plume structure; Scientific drilling; Source region; Thermal boundary layer; Three-dimensional numerical simulations; Time-scales; Topdown; fluid dynamics; igneous geochemistry; isotopic composition; lava; mantle plume; simulation; volcano; Volcanoes https://www.scopus.com/inward/record.uri?eid=2-s2.0-77953024036&doi=10.1016%2fj.epsl.2010.04.005&partnerID=40&md5=f96941980f7d8440fc7c46858bbf0b5a Cited by: 74 Cinzia G. Farnetani Albrecht W. Hofmann article Ren20091553 Numerous geochemical studies have indicated that the Hawaiian mantle plume consists of several distinct components. However, their origin remains controversial, with a number of different interpretations having been proposed. We present new major element, trace element and high-precision Sr-Nd-Pb-He isotope data for a suite of fresh submarine lavas erupted by the Koolau, Kilauea and Loihi volcanoes, which are widely believed to have sampled three distinct Hawaiian plume components. The Sr and Nd isotope compositions of the Loihi lavas are similar to those of Kilauea lavas. However, our double-spike Pb isotopic data show that Loihi lavas have both Kilauea-like and Loihi-like compositions. This discovery implies that the Loihi source region contains a Kilauea-like ('Kea') mantle component. Our new data support the existence of three major types of intrinsic plume component: a Loihi component, an 'enriched' (Koolau) component and a 'depleted' (Kea) component. We propose that the Loihi component is a common component, forming the matrix in the Hawaiian mantle plume, and that the isotopic differences between the various shield lavas reflect different mixing proportions of the Loihi component and recycled oceanic crust components (EM-1-like and HIMU-like). The Koolau component contains a higher proportion of EM-1, whereas the Kea component contains a higher proportion of HIMU. EM-1- and HIMU-like recycled oceanic crust components are distributed on a fine scale throughout the peridotitic matrix within the Hawaiian plume. Both components are present in the sources beneath Kea- and Loa-trend volcanoes. We infer that the thermal structure and spatially distributed compositional heterogeneity of the plume are important in controlling the isotopic composition of lavas from a given Hawaiian volcano. © The Author 2009. Published by Oxford University Press. All rights reserved. 2009 English 00223530 10.1093/petrology/egp041 Journal of Petrology 50 1553-1573 Key Laboratory of Isotope Geochronology and Geochemistry, Guangzhou Institute of Geochemistry (GIG), Chinese Academy of Sciences (CAS), 511 Kehua Street, Wushan, Guangzhou 510640, China; Institute for Research on Earth Evolution (IFREE), JAPAN Agency for Marine-Earth Science and Technology (JAMSTEC), 2-5 Natsushima-Cho, Yokosuka, Kanagawa 237-0061, Japan 8 helium isotope; heterogeneity; igneous geochemistry; isotopic composition; lava; lead isotope; mantle chemistry; mantle plume; neodymium isotope; oceanic crust; partial melting; precision; shield; source rock; spatial distribution; strontium isotope, Hawaii [United States]; North America; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-68249147528&doi=10.1093%2fpetrology%2fegp041&partnerID=40&md5=0fd9e7166c344b5250d2a6004ee4d269 cited By 45 Z.-Y. Ren T. Hanyu T. Miyazaki Q. Chang H. Kawabata T. Takahashi Y. Hirahara A.R.L. Nichols Y. Tatsumi article Farnetani2009314 Geochemical studies, including those made possible by the Hawaiian Scientific Drilling Project, have revealed the chemically and isotopically heterogeneous nature of hotspot lavas, yet their interpretation is highly controversial and there is little agreement as to how geochemical heterogeneities might be spatially arranged within the plume conduit. To address this issue we conduct high resolution numerical simulations of an axisymmetric purely thermal plume, focusing on the lower mantle part of the conduit and on the thermal boundary layer (TBL) feeding the plume. We explore the relation between length-scales of heterogeneities across the source region and the length- and time-scales of geochemical variations in the plume conduit. The vertical velocity inside the conduit decreases exponentially with the square of radial distance generating high strain rates (order 10- 13-10- 14 s- 1) that modify the shape of upwelling heterogeneities into elongated and narrow filaments. Therefore, the preservation of 'blob-like' heterogeneities (i.e., with a 1:1 aspect ratio in a vertical section) is quite unlikely, even in the central part of the plume. For example, initial lenses of size 100 × 10 km in the TBL are stretched into filaments 500-1000 km long. These filaments constitute 'long-lived' structures in a rising plume, and their geochemical fingerprints may be registered at a given radial distance for several millions of years. We also consider an idealized heterogeneous architecture inside the TBL, consisting of 'trains' of small scale lenses. When such trains upwell in the conduit, they form high radial geochemical gradients. Their 'geochemical record', registered over time at a given depth and radial distance, will fluctuate over time, with shorter period and a larger amplitude at the conduit center than at its periphery. Finally, we demonstrate that material existing 'side by side' in the conduit originated from regions in the TBL that are separated by distances of several hundred kilometers. This implies that vigorous plumes are able to sample, and to bring side by side, very distant portions of their source region. Our results provide a fluid dynamically consistent framework to discuss the main aspects of the different (and to some extent mutually exclusive) models of conduit structure used to interpret the geochemical observations of the Hawaiian lavas. © 2009 Elsevier B.V. All rights reserved. Article 2009 English 0012821X 10.1016/j.epsl.2009.03.035 Earth and Planetary Science Letters 282 314 – 322 1-4 Hawaii [United States]; North America; United States; Aspect ratio; Filaments (lamp); Lenses; Locomotives; Optical instruments; Railroad cars; Strain rate; Transport properties; Axi-symmetric; Conduit structures; Geochemical fingerprints; geochemical heterogeneity; Geochemical variations; Hawaiian plume; Heterogeneous architectures; High strain rates; High-resolution numerical simulations; Hot spots; Internal structures; Lower mantles; mantle plumes; Radial distances; Scientific drillings; Small scale; Source regions; Thermal boundary layers; Time-scales; Vertical sections; Vertical velocities; isotopic composition; lower mantle; mantle chemistry; mantle plume; numerical model; Thermal plumes https://www.scopus.com/inward/record.uri?eid=2-s2.0-67349118868&doi=10.1016%2fj.epsl.2009.03.035&partnerID=40&md5=5ae64fb76550dcc070f87710260f6f69 Cited by: 68 Cinzia G. Farnetani Albrecht W. Hofmann article Stolper20094 The Hawaii Scientific Drilling Project drilled and cored two holes in Hilo, Hawaii, the deeper reaching a depth of 3508 mbsl, and it retrieved a total of 4600 meters of rock core (525 meters from the Mauna Loa volcano and the remainder from the Mauna Kea volcano). The Mauna Loa core extends the continuous lava stratigraphy of that volcano back to 100 ka and reveals major changes in lava geochemistry over that time period. The Mauna Kea core spans an age range from about 200 ka to perhaps 700 ka, and when combined with surface outcrops, it provides a 700-kyr record of the lava output from a single volcano. During the time covered by the lavas from the core, the volcano drifted some 60-80 km across the melting region of the Hawaiian mantle plume, and therefore the HSDP rock core provides the first systematic cross-sectional sampling of a deep mantle plume. The geochemical characterization of the core, which involved an international team of forty scientists over a period of fifteen years provides information about mantle plume structure and ultimately about the deepest parts of the Earth's mantle. The study of the lava core (which still continues) has provided unprecedented information about the internal structure of a large oceanic volcano and the time scale over which volcanoes grow. The hole also provides an intriguing glimpse of a complex subsurface hydrological regime that differs greatly from the generalized view of ocean island hydrology. Drilling conditions were favorable in the subaerial parts of the volcanic section, where coring was generally fast and efficient. The submarine part of the lava section, made up primarily of volcanogenic sediments and pillow lavas, proved considerably more difficult to drill. Some of the difficulties and considerable additional expense were due to pressurized aquifers at depth and a few critical mistakes made while setting casing. Even with the more difficult conditions, the project retrieved about 2400 meters of nearly continuous core from the submarine section of Mauna Kea. Overall, the HSDP project was highly successful even though the original target depth was about 20% deeper than the final hole depth. As expected, the project results answer several important questions about oceanic volcanoes, mantle plumes, and ocean island water resources, but they raise many more that might be addressed with further moderate-depth drilling in other Hawaiian volcanoes. 2009 English 18168957 10.2204/iodp.sd.7.02.2009 Scientific Drilling 4-14 Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, United States; Department of Earth and Planetary Science, University of California Berkeley, Earth Sciences Division, Berkeley, CA 94720, United States; Center for Study of Active Volcanoes, University of Hawaii at Hilo, 200 West Kawili Street, Hilo, HI 96720, United States 7 Deep drillings; Earth's mantles; Geochemical characterizations; Hole depths; Hydrological regimes; Internal structures; International teams; Mantle plumes; Mauna Loa; Oceanic volcanoes; Pillow lavas; Rock cores; Scientific drillings; Time periods; Time-scale; Volcanogenic sediments, Aquifers; Hydrogeology; Ocean engineering; Oceanography; Offshore oil wells; Rock drilling; Stratigraphy; Submarines; Thermal plumes; Water; Water resources, Volcanoes https://www.scopus.com/inward/record.uri?eid=2-s2.0-78651564480&doi=10.2204%2fiodp.sd.7.02.2009&partnerID=40&md5=aa9d7c4f9af6f8b1284d60673a3412be cited By 40 E.W. Stolper D.J. DePaolo D.M. Thomas article Nichols20091052 Cooling rates have been determined for basaltic glasses from different depths of the submarine section of the drill core recovered in the 1999 phase of Hawaii Scientific Drilling Project (HSDP2). The glasses include degassed blocky hyaloclastite clasts and undegassed pillow rims. The degassed glassy clasts were generated in subaerial or shallow submarine environments, during explosive interactions between lava and seawater, before eventual deposition under water. The volatile contents of the glassy pillow rims are consistent with eruption and quenching in water several hundred metres deep. The cooling rates have been calculated from the calorimetric properties of the glass across the glass transition. The heat capacity (cp) of each sample was measured during several cycles of heating from room temperature to temperatures above their glass transition using a differential scanning calorimeter (DSC). Their compositions did not change during the thermal treatment, a prerequisite for successful cp measurements, although the glasses with higher H2O contents became more opaque and their mid-IR spectra changed. Each cp-T path exhibits the now classic features of the glass transition; glassy and liquid states separated by a hysteresis marking the transition. After experiencing the same experimental thermal history the glass transition occurs at lower temperatures in glasses with higher H2O contents. Except for one sample, the cp-T path measured on initial heating also releases energy stored during the natural quench, which is not recovered during subsequent experimental cooling. The energy stored in the HSDP2 glasses is much less than that observed in hyperquenched natural and synthetic glasses. Even so, the Tool-Narayanaswamy enthalpy relaxation geospeedometer, usually used to determine the cooling rates in volcanic glasses, is unable to deal with this energy release. For those samples that exhibit this feature an alternative method, developed for hyperquenched glasses, is applied. This uses the energy released to calculate Tf, from which the cooling rate is calculated. The degassed blocky hyaloclastite clasts exhibit cooling rates 0.1-72.2 K s-1, while the undegassed pillow rims span 0.2-46.4 K s-1. The fastest cooling rates are consistent with the cooling of lava bodies in seawater. The wide variation for both types of glass could reflect quenching at different distances from the basalt-seawater interface. However, for the degassed hyaloclastite clasts the range could indicate that the clasts were generated by different processes operating during the explosive interaction between lava and seawater in the littoral zone. In the undegassed pillow lavas, glassy rims may have been reheated, giving rise to more complex, slower, thermal histories, as a result of latent heat released during the crystallisation of pillow interiors, or flow replenishment. Both types of glass may also have experienced reheating from succeeding flows or deposits. Compared to deep-sea limu o Pele hyaloclastite fragments, whose hyperquench rates indicate simultaneous cooling and fragmentation, the shallow blocky hyaloclastite clasts may have formed during post-cooling brittle fragmentation. © 2008 Elsevier Ltd. All rights reserved. Article 2009 English 00167037 10.1016/j.gca.2008.11.023 Geochimica et Cosmochimica Acta 73 1052 – 1066 4 basalt; calorimetry; chemical composition; clastic rock; cooling; Deep Sea Drilling Project; deposition; differential thermal analysis; experimental study; fragmentation; hyaloclastite; phase transition; pillow lava; underwater environment; volatile substance https://www.scopus.com/inward/record.uri?eid=2-s2.0-58849124776&doi=10.1016%2fj.gca.2008.11.023&partnerID=40&md5=8f7dba10642e2acbf024f9f7b824d2e2 Cited by: 34 A.R.L. Nichols M. Potuzak D.B. Dingwell article Walton2008351 Elongate, fine tubes, ∼1 μm wide and up to 200 μm long, extend from fractured surfaces, vesicle walls, and internal fractures into fragments of basalt glass in samples from the Hawaii Scientific Drilling Project #2 phase 1 (HSDP #21) core and the Hilina slope, Hawaii. Several features indicate that these tubes are microbial endolithic microborings: the tubes resemble many described microborings from oceanic basalt glass, their formation is postdepositional but restricted to certain but different ranges of time in the two sets of samples, and they are not uniformly distributed throughout glass fragments. Microtubules record several characteristic behaviors including boring into glass, mining, seeking olivine, and avoiding plagioclase. They also are highly associated with a particular form of glass-replacing smectite. Evidence of behavior should join morphological and geochemical criteria in indicating microbial alteration of basalt glass. In some samples, steeply conical tubes, ∼10-20 μm in diameter tapering to 1 μm and commonly filled with smectite, appear to be modifications or elaborations of the microtubules. These also curve toward olivine and are associated with replacement smectite. In HSDP #21 samples, microtubules initiated at margins of shards before palagonite replaced those margins and are preserved during palagonitization. In fact, microtubules appear to have provided routes that enhanced the efficiency of water's reaching of unaltered glass. In Hilina Slope samples, the microtubules appear to postdate palagonitization because they initiate at the boundary between palagonite and unaltered sideromelane. Preservation of microtubules during palagonitization in samples together with recognition of other associated characteristics representing behavior suggests that such features may be recognizable in more heavily altered ancient rocks. © 2008 The Author. 2008 English 14724677 10.1111/j.1472-4669.2008.00149.x Geobiology 6 351-364 Department of Geology, University of Kansas, 1475 Jayhawk Blvd, Lawrence, KS 66045, United States 4 silicate; silicon dioxide, basalt; endolithon; microorganism; olivine; palagonite; smectite; species occurrence, article; basalt; chemistry; microbiology; microscopy; microtubule; United States, Hawaii; Microscopy; Microtubules; Silicates; Soil Microbiology https://www.scopus.com/inward/record.uri?eid=2-s2.0-49249128065&doi=10.1111%2fj.1472-4669.2008.00149.x&partnerID=40&md5=dc9feeb56b04cba82fb33697eeb8455f cited By 40 A.W. Walton article Thompson2008163 Hawaiian Island flank failures are recognized as the largest landslide events on Earth, reaching volumes of several thousand cubic kilometers and lengths of over 200 km and occurring on an average of once every 100 000 years. The 3.1 km deep Hawaii Scientific Drilling Project (HSDP) enabled an investigation of the rock mass strength variations on the island of Hawaii [Schiffman, P., Watters, R.J., Thompson, N., Walton, A.W., 2006. Hyaloclastites and the slope stability of Hawaiian volcanoes: insights from the Hawaiian Scientific Drilling Project's 3-km drill core. Journal of Volcanology and Geothermal Research, 151 (1-3): 217-228]. This study builds on that of Schiffman et al. [Schiffman, P., Watters, R.J., Thompson, N., Walton, A.W., 2006. Hyaloclastites and the slope stability of Hawaiian volcanoes: Insights from the Hawaiian Scientific Drilling Project's 3-km drill core. Journal of Volcanology and Geothermal Research, 151 (1-3): 217-228] by considering more in-depth rock mass classification and strength testing methods of the HSDP core. Geotechnical core logging techniques combined with laboratory strength testing methods show that rock strength differences exist within the edifice. Comparing the rock strength parameters obtained from the various volcano lithologies identified weak zones, suggesting the possible location of future slip surfaces for large flank failures. Relatively weak rock layers were recognized within poorly consolidated hyaloclastite zones, with increases in strength based on degree of alteration. Subaerial and submarine basalt flows are found to be significantly stronger. With the aid of digital elevation models, cross-sections have been developed of key flank areas on the island of Hawaii. Limit equilibrium slope stability analyses are performed on each cross-section using various failure criteria for the rock mass strength calculations. Based on the stability analyses the majority of the slopes analyzed are considered stable. In cases where instability (i.e. failure) is predicted, decreased rock mass quality (strength) of the altered and highly poorly consolidated lithologies is found to have a significant influence. These lithologies are present throughout the Hawaiian Islands, representing potential failure surfaces for large flank collapses. Failure criterion input parameters are considered in sensitivity analyses as are the influences of certain external stability factors such as sea level variation and seismic loading. © 2007 Elsevier B.V. All rights reserved. Article 2008 English 03770273 10.1016/j.jvolgeores.2007.11.008 Journal of Volcanology and Geothermal Research 171 163-177 School of Conservation Sciences, Bournemouth University, United Kingdom; Department of Geological Sciences and Engineering, University of Nevada, Reno, United States; Department of Geology, University of California, Davis, United States 3-4 Failure analysis; Landslides; Lithology; Sensitivity analysis; Volcanic rocks, Digital elevation models; Edifice stability; Hawaiian Island flank failures; Volcanic slope stability, Volcanoes, collapse; core logging; digital elevation model; failure analysis; limit analysis; rock mass classification; sensitivity analysis; slope stability; stability analysis; strength; testing method, Hawaiian Islands; Pacific islands; Pacific Ocean https://www.scopus.com/inward/record.uri?eid=2-s2.0-41749100594&doi=10.1016%2fj.jvolgeores.2007.11.008&partnerID=40&md5=b02ea5897d32e08cda434597cd11c8cd cited By 12 N. Thompson R.J. Watters P. Schiffman article Garcia2007 The Hawai'i Scientific Drilling Project (HSDP2) successfully drilled ∼3.1 km into the island of Hawai'i. Drilling started on Mauna Loa volcano, drilling 247mof subaerial lavas before encountering 832m of subaerial Mauna Kea lavas, followed by 2019 m of submarine Mauna Kea volcanic and sedimentary units. The 2.85 km stratigraphic record of Mauna Kea volcano spans back to ∼650 ka. Mauna Kea subaerial lavas have high average olivine contents (13 vol.%) and low average vesicle abundances (10 vol.%). Most subaerial Mauna Kea flows are 'a'ā (∼63%), whereas the Mauna Loa section contains nearly equal amounts of pāhoehoe and 'a'ā (like its current surface). The submarine Mauna Kea section contains an upper, ∼900 m thick, hyaloclastite-rich section and a lower, ∼1100 m thick, pillow-lavadominated section. These results support a model that Hawaiian volcanoes are built on a pedestal of pillow lavas capped by rapidly quenched, fragmented lava debris. The HSDP2 section is compared here to a 1.7 km deep hole (SOH1) on Kilauea's lower east rift zone. Differences in the sections reflect the proximity to source vents and the lower magma supply to Kilauea's rift zone. Both drill core sections are cut by intrusions, but the higher abundance of intrusions in SOH1 reflects its location within a rift zone, causing more extensive alteration in the SOH1 core. The HSDP2 site recovered a relatively unaltered core well suited for geochemical analyses of the single deepest and most complete borehole ever drilled through a Hawaiian or any other oceanic island volcano. Copyright 2007 by the American Geophysical Union. Article 2007 English 15252027 10.1029/2006GC001379 Geochemistry, Geophysics, Geosystems 8 2 https://www.scopus.com/inward/record.uri?eid=2-s2.0-58849162832&doi=10.1029%2f2006GC001379&partnerID=40&md5=7877eb9ce27e29e3ec6ac7daacbc4dc4 Cited by: 59; All Open Access, Green Open Access Michael O. Garcia Eric H. Haskins Edward M. Stolper Michael Baker conference Berner200761 The study investigates the geochemistry of sulfur in the sequence of volcanic rocks recovered by a 3098m deep drilling executed on the flank of the Mauna Kea volcano. Though mineralogic investigations indicate the presence of sulfur bearing minerals which may have crystallized directly from the plume melt, contents and isotopic composition of sulfur suggest that the original composition of the melt was altered due to degassing and interaction with seawater derived fluids. © 2007 Taylor & Francis Group, London. Conference paper 2007 English 978-041545135-2 Water-Rock Interaction - Proceedings of the 12th International Symposium on Water-Rock Interaction, WRI-12 1 61 – 64 Degassing; Geochemistry; Offshore oil wells; Sulfur; Volcanic rocks; Weathering; Deep drilling; Isotopic composition; Seawater https://www.scopus.com/inward/record.uri?eid=2-s2.0-84858020648&partnerID=40&md5=be691d87fcf45e70a69f4ffae02bea13 Cited by: 0 Z. Berner G. Istrate D. Stüben article Herzberg2006605 There is uncertainty about whether the abundant tholeiitic lavas on Hawaii are the product of melt from peridotite or pyroxenite/eclogite rocks. Using a parameterization of melting experiments on peridotite with glass analyses from the Hawaii Scientific Deep Project 2 on Mauna Kea volcano, I show here that a small population of the core samples had fractionated from a peridotite-source primary magma. Most lavas, however, differentiated from magmas that were too deficient in CaO and enriched in NiO (ref. 2) to have formed from a peridotite source. For these, experiments indicate that they were produced by the melting of garnet pyroxenite, a lithology that had formed in a second stage by reaction of peridotite with partial melts of subducted oceanic crust. Samples in the Hawaiian core are therefore consistent with previous suggestions that pyroxenite occurs in a host peridotite, and both contribute to melt production. Primary magma compositions vary down the drill core, and these reveal evidence for temperature variations within the underlying mantle plume. Mauna Kea magmatism is represented in other Hawaiian volcanoes, and provides a key for a general understanding of melt production in lithologically heterogeneous mantle. ©2006 Nature Publishing Group. 2006 English 00280836 10.1038/nature05254 Nature 444 Nature Publishing Group 605-609 Department of Geological Sciences, Rutgers University, Piscataway, NJ 08854, United States 7119 Lithology; Melting; Rocks; Thermal plumes; Uncertain systems; Volcanoes, Hawaiian core; Mauna Kea magmatism; Pyroxenite/eclogite rocks; Tholeiitic lavas, Petrology, aluminum derivative; aluminum trioxide; calcium oxide; chromium trioxide; dipotassium oxide; glass; iron oxide; iron trioxide; magnesium oxide; manganese oxide; nitrogen oxide; oxacillin; oxide; phosphorus pentoxide; potassium derivative; silicon dioxide; titanium dioxide, core analysis; lava; magma; mantle plume; oceanic crust; peridotite; petrology; pyroxenite; thermal structure; tholeiite, article; calibration; crystallization; fractionation; garnet; melting point; peridotite; petrology; priority journal; pyroxenite; rock; volcano https://www.scopus.com/inward/record.uri?eid=2-s2.0-33845257871&doi=10.1038%2fnature05254&partnerID=40&md5=cd5e1c7a0245f32daaf1e89426bf67d1 cited By 220 C. Herzberg article Sharp2005 The Hawaii Scientific Drilling Project, phase 2 (HSDP-2), recovered core from a ∼3.1-km-thick section through the eastern flanks of Mauna Loa and Mauna Kea volcanoes. We report results of 40Ar/39Ar incremental heating by broad-beam infrared laser of 16 basaltic groundmass samples and 1 plagioclase separate, mostly from K-poor tholeiites. The tholeiites generally have mean radiogenic 40Ar enrichments of 1-3%, and some contain excess 40Ar; however, isochron ages of glass-poor samples preserve stratigraphic order in all cases. A 246-m-thick sequence of Mauna Loa tholeiitic lavas yields an isochron age of 122 ± 86 kyr (all errors 2<r) at its base. Beneath the Mauna Loa overlap sequence lie Mauna Kea's postshield and shield sequences. A postshield alkalic lava yields an age of 236 ± 16 kyr, in agreement with an age of 240 ± 14 kyr for a geochemically correlative flow in the nearby HSDP-1 core hole, where more complete dating of the postshield sequence shows it to have accumulated at 0.9 ± 0.4 m/kyr, from about 330 to <200 ka. Mauna Kea's shield consists of subaerial tholeiitic flows to a depth of 1079 m below sea level, then shallow submarine flows, hyaloclastites, pillow lavas, and minor intrusions to core bottom at 3098 m. Most subaerial tholeiitic flows fail to form isochrons; however, a sample at 984 m yields an age of 370 ± 180 kyr, consistent with ages from similar levels in HSDP-1. Submarine tholeiites including shallow marine vitrophyres, clasts from hyaloclastites, and pillow lavas were analyzed; however, only pillow lava cores from 2243, 2614, and 2789 m yield reliable ages of 482 ± 67, 560 ± 150, and 683 ± 82 kyr, respectively. A linear fit to ages for shield samples defines a mean accumulation rate of 8.6 ± 3.1 m/kyr and extrapolates to ∼635 kyr at core bottom. Alternatively, a model relating Mauna Kea's growth to transport across the Hawaiian hot spot that predicts downward accelerating accumulation rates that reach ∼20 m/kyr at core bottom (DePaolo and Stolper, 1996) is also consistent with all reliable ages except the deepest. Copyright 2005 by the American Geophysical Union. Article 2005 English 15252027 10.1029/2004GC000846 Geochemistry, Geophysics, Geosystems 6 4 https://www.scopus.com/inward/record.uri?eid=2-s2.0-22444447594&doi=10.1029%2f2004GC000846&partnerID=40&md5=51e8e430a553cfe0774c59d05065eb52 Cited by: 114; All Open Access, Bronze Open Access Warren D. Sharp Paul R. Renne article Vahle2005110 We applied the field dependence parameter χHd (%) = [(k300A/m-k30A/m)/k300A/m] × 100 given by de Wall for the subaerial and submarine basalts drilled by the 3109 m deep HSDP-2 borehole on Hawaii in order to verify the hypothesis that mainly composition controls the field dependence of AC susceptibility in titanomagnetite of natural occurrences. When we used this parameter, our data showed a significant scattering compared to data presented in earlier studies. In addition to composition, the effect of measurement temperature, grain size and anisotropy on the field dependent susceptibility were examined and found to be critical. The impact of grain size is weaker than the other effects. It cannot be totally excluded that the observed effects arise indirectly through an overlap of the other effects for the investigated basalts. The most important factor for the variation of field dependence is the degree of oxidation, causing a modification of the titanomagnetite composition or formation of titanomaghemite, and the mixing of Ti-rich with Ti-poor titanomagnetites, which strongly reduces the χHd parameter. Field dependence is not only related to titanomagnetite composition, especially for intermediate titanomagnetites with TCs between 100 and 300 °C. Temperature dependent susceptibility measurements at different field amplitudes for these intermediate types showed at constant geometry of the k(T) curve great differences in susceptibility, resulting in significant changes of the field dependence parameter over the temperature interval from - 100 to 260 °C. herefore variations of the ambient measurement temperatures are able to influence the field dependence. The second important effect is the degree of particle shape and alignment, which controls the field dependence in different orientations especially for the intermediate titanomagnetite, which is intensively intergrown with elongated hemoilmenite grains. As a consequence, samples with higher degrees of anisotropy exhibit differences of the field dependence parameter if measured parallel to kmax or kmin axis. Therefore, in addition to compositional effects and the temperature dependence, the magnetic fabric has to be considered for the interpretation of field dependent susceptibility measurements. The influence of intrinsic (Ti-content, magnetocrystalline anisotropy), and extrinsic (shape and alignment of grains) factors for the interpretation of the degree of anisotropy has to be kept in mind when interpreting AMS data in terms of strain rates experienced by moving lava during emplacement. © 2005 Elsevier B.V. All rights reserved. Article 2005 English 0012821X 10.1016/j.epsl.2005.07.010 Earth and Planetary Science Letters 238 110 – 129 1-2 Hawaii [(ISL) Hawaiian Islands]; Hawaii [United States]; Hawaiian Islands; North America; oceanic regions; Pacific islands; Pacific Ocean; United States; Western Hemisphere; World; Basalt; Composition effects; Grain size and shape; Magnetic susceptibility; Magnetite; Mineralogy; Oxidation; Field dependence; Magnetic fabrics; Magnetic mineralogy; Titanomagnetite; basalt; magnetic field; magnetic susceptibility; titanomagnetite; Geochemistry https://www.scopus.com/inward/record.uri?eid=2-s2.0-26944501970&doi=10.1016%2fj.epsl.2005.07.010&partnerID=40&md5=18996f05ff3a683ac3f3c8a1f8c76357 Cited by: 21 Carsten Vahle article Ren2005837 The Hawaiian-Emperor volcanic island and seamount chain is usually attributed to a hot mantle plume, located beneath the Pacific lithosphere, that delivers material sourced from deep in the mantle to the surface. The shield volcanoes of the Hawaiian islands are distributed in two curvilinear, parallel trends (termed 'Kea' and 'Loa'), whose rocks are characterized by general geochemical differences. This has led to the proposition that Hawaiian volcanoes sample compositionally distinct, concentrically zoned, regions of the underlying mantle plume. Melt inclusions, or samples of local magma 'frozen' in olivine phenocrysts during crystallization, may record complexities of mantle sources, thereby providing better insight into the chemical structure of plumes. Here we report the discovery of both Kea- and Loa-like major and trace element compositions in olivine-hosted melt inclusions in individual, shield-stage Hawaiian volcanoes-even within single rock samples. We infer from these data that one mantle source component may dominate a single lava flow, but that the two mantle source components are consistently represented to some extent in all lavas, regardless of the specific geographic location of the volcano. We therefore suggest that the Hawaiian mantle plume is unlikely to be compositionally concentrically zoned. Instead, the observed chemical variation is probably controlled by the thermal structure of the plume. 2005 English 00280836 10.1038/nature03907 Nature 436 837-840 Department of Earth and Planetary Sciences, Tokyo Institute of Technology, 2-12-1 Ookayama, Meguro-ku, 152-8551, Japan; Institute for Frontier Research on Earth Evolution, Japan Agency for Marine-Earth Science and Technology, Natsushima-cho 2-15, Yokosuka, Kanagawa 237-0061, Japan; School of Ocean and Earth Science and Technology, University of Hawaii, POST 615A, 1680 East-West Road, Honolulu, HI 96822, United States 7052 Crystallization; Geochemistry; Olivine; Thermal plumes, Lithospheres; Mantle plumes; Olivine phenocryst; Volcanic islands, Volcanic rocks, trace element, chemical composition; mantle chemistry; mantle plume; melt inclusion; seamount, article; chemical composition; geochemistry; geography; geology; heat; island (geological); lava; lithosphere; mantle plume; priority journal; rock; thermal structure; United States; volcano, Hawaiian Islands; oceanic regions; Pacific islands; Pacific Ocean; World https://www.scopus.com/inward/record.uri?eid=2-s2.0-23844542458&doi=10.1038%2fnature03907&partnerID=40&md5=4371d1afabb8791da380bc004c4784d3 cited By 104 Z.-Y. Ren S. Ingle E. Takahashi N. Hirano T. Hirata article Bryce2005 Sr, Nd, and Os isotopic measurements were made on 110 Mauna Kea lava and hyaloclastite samples from the drillcore retrieved from the second phase of the Hawaii Scientific Drilling Project (HSDP-2). The samples come from depths of 255 to 3098 meters below sea level, span an age range from 200 to about 550-600 kyr, and represent an ordered record of the lava output from Mauna Kea volcano as it drifted a distance of about 40 km over the magma-producing region of the Hawaiian hot spot. The deepest (oldest) samples represent the time when Mauna Kea was closest to the center of the melting region of the Hawaiian plume. The Sr and Os isotopic ratios in HSDP-2 lavas show only subtle isotopic shifts over the ∼400 kyr history represented by the core. Neodymium isotopes (∈Nd values) increase systematically with decreasing age from an average value of nearly +6.5 to an average value of +7.5. This small change corresponds to subtle shifts in 87Sr/86Sr and 187Os/188Os isotope ratios, with small shifts of ∈Hf, a large shift in 208Pb/204Pb and 208Pb/207Pb values, and with a very large shift in He isotope ratios from R/RA values of about 7-8 to values as high as 25. When Mauna Kea was closest to the plume core, the magma source did not have primitive characteristics for Nd, Sr, Pb, Hf, and Os isotopes but did have variable amounts of "primitive" helium. The systematic shifts in Nd, Hf, Pb, and He isotopes are consistent with radial isotopic zoning within the melting region of the plume. The melting region constitutes only the innermost, highest-temperature part of the thermally anomalous plume mantle. The different ranges of values observed for each isotopic system, and comparison of Mauna Kea lavas with those of Mauna Loa, suggest that the axial region of the plume, which has a radius of ∼20 km, is a mixture of recycled subducted components and primitive lower mantle materials, recently combined during the formational stages of the plume at the base of the mantle. The proportions of recycled and primitive components are not constant, and this requires there be longitudinal (vertical) heterogeneity within the core of the plume. The remainder of the plume, outside this plume "core zone," is less heterogeneous but distinct from upper mantle as represented by mid-ocean ridge basalt (MORB). The plume structure may provide a detailed view of mantle isotopic composition near the core-mantle boundary. Copyright 2005 by the American Geophysical Union. 2005 English 15252027 10.1029/2004GC000809 Geochemistry, Geophysics, Geosystems 6 Center for Isotope Geochemistry, Department of Earth and Planetary Science, University of California, Berkeley, CA 94720-4767, United States; Department of Earth Sciences, University of New Hampshire, James Hall, 56 College Road, Durham, NH 03824, United States; Max-Planck Institut für Chemie, Postfach 3060, D-55020 Mainz, Germany; Geological Sciences Department, University of Texas at Austin, 1 University Station C1100, Austin, TX 78712-0254, United States 9 https://www.scopus.com/inward/record.uri?eid=2-s2.0-33750609019&doi=10.1029%2f2004GC000809&partnerID=40&md5=61a45362363bbef1694a2566dac3307f cited By 90 J.G. Bryce D.J. DePaolo J.C. Lassiter article Morin20051 As part of the Hawaii Scientific Drilling Project (HSDP), an exploratory hole was drilled in 1993 to a depth of 1056 meters below sea level (mbsl) and a deeper hole was drilled to 3098 mbsl in 1999. A set of geophysical well logs was obtained in the deeper hole that provides fundamental information regarding the structure and the state of stress that exist within a volcanic shield. The acoustic televiewer generates digital, magnetically oriented images of the borehole wall, and inspection of this log yields a continuous record of fracture orientation with depth and also with age to 540 ka. The data depict a clockwise rotation in fracture strike through the surficial Mauna Loa basalts that settles to a constant heading in the underlying Mauna Kea rocks. This behavior reflects the depositional slope directions of lavas and the locations of volcanic sources relative to the drill site. The deviation log delineates the trajectory of the well bore in three-dimensional space. This path closely follows changes in fracture orientation with depth as the drill bit is generally prodded perpendicular to fracture strike during the drilling process. Stress-induced breakouts observed in the televiewer log identify the orientations ot the maximum and minimum horizontal principal stresses to be north-south and east-west, respectively. This stress state is attributed to the combination of a sharp break in onshore-offshore slope that reduces stress east-west and the emergence of Kilauea that increases stress north-south. Breakouts are extensive and appear over approximately 30% of the open hole. Copyright 2005 by the American Geophysical Union. Article 2005 English 21699313 10.1029/2004JB003410 Journal of Geophysical Research: Solid Earth 110 Blackwell Publishing Ltd 1 – 8 7 Hawaiian Islands; oceanic regions; Pacific islands; Pacific Ocean; World; ocean island basalt; stress field; structural geology; volcanic island https://www.scopus.com/inward/record.uri?eid=2-s2.0-25444439015&doi=10.1029%2f2004JB003410&partnerID=40&md5=c4db4d7da511a43734e3276c31c7b7f6 Cited by: 9; All Open Access, Bronze Open Access, Green Open Access Roger H. Morin Roy H. Wilkens article Abouchami2005851 The two parallel chains of Hawaiian volcanoes ('Loa' and 'Kea') are known to have statistically different but overlapping radiogenic isotope characteristics. This has been explained by a model of a concentrically zoned mantle plume, where the Kea chain preferentially samples a more peripheral portion of the plume. Using high-precision lead isotope data for both centrally and peripherally located volcanoes, we show here that the 'two trends have very little compositional overlap and instead reveal bilateral, non-concentric plume zones, probably derived from the plume source in the mantle. On a smaller scale, along the Kea chain, there are isotopic differences between the youngest lavas from the Mauna Kea and Kilauea volcanoes, but the 550-thousand-year-old Mauna Kea lavas are isotopically identical to Kilauea lavas, consistent with Mauna Kea's position relative to the plume, which was then similar to that of present-day Kilauea. We therefore conclude that narrow (less than 50 kilometres wide) compositional streaks, as well as the larger-scale bilateral zonation, are vertically continuous over tens to hundreds of kilometres within the plume. 2005 English 00280836 10.1038/nature03402 Nature 434 851-856 Max-Planck-Institut für Chemie, Postfach 3060, 55020 Mainz, Germany; Massachusetts Inst. of Technology, Cambridge, MA 02139, United States; Department of Geological Sciences, Rutgers University, New Brunswick, NJ 08903, United States 7035 Composition; Geographical regions; Geophysics; Lead; Volcanoes, Isotopy; Lead isotopes; Mantle plume; Radiogenic isotopes, Radioisotopes, isotope; lead, isotopic composition; lava flow; lead; mantle plume, accuracy; article; chemical composition; evolution; geographic distribution; parameter; plume; priority journal; radioactivity; regression analysis; sampling; technique; theoretical model; United States; volcano, Hawaii [(ISL) Hawaiian Islands]; Hawaii [United States]; Hawaiian Islands; Mauna Kea; Mauna Loa; North America; oceanic regions; Pacific islands; Pacific Ocean; United States; Western Hemisphere; World https://www.scopus.com/inward/record.uri?eid=2-s2.0-17644365383&doi=10.1038%2fnature03402&partnerID=40&md5=209c60037850d04b4ae9f90035d8f4b1 cited By 204 W. Abouchami A.W. Hofmann S.J.G. Galer F.A. Frey J. Eisele M. Felgenson article Sobolev2005590 More than 50 per cent of the Earth's upper mantle consists of olivine and it is generally thought that mantle-derived melts are generated in equilibrium with this mineral. Here, however, we show that the unusually high nickel and silicon contents of most parental Hawaiian magmas are inconsistent with a deep olivine-bearing source, because this mineral together with pyroxene buffers both nickel and silicon at lower levels. This can be resolved if the olivine of the mantle peridotite is consumed by reaction with melts derived from recycled oceanic crust, to form a secondary pyroxenitic source. Our modelling shows that more than half of Hawaiian magmas formed during the past 1 Myr came from this source. In addition, we estimate that the proportion of recycled (oceanic) crust varies from 30 per cent near the plume centre to insignificant levels at the plume edge. These results are also consistent with volcano volumes, magma volume flux and seismological observations. 2005 English 00280836 10.1038/nature03411 Nature 434 590-597 Max-Planck-Institut für Chemie, Postfach 3060, 55020 Mainz, Germany; Vernadsky Institute of Geochemistry, Russian Academy of Sciences, Kosygin street 19, 117975 Moscow, Russian Federation; GeoForschungsZentrum, Telegrafenberg E, D-14473, Potsdam, Germany; Institute of Physics of the Earth, Russian Academy of Sciences, B. Gruzinskaya street 10, 123995 Moscow, Russian Federation; Faculty of Geosciences, Department of Petrology, Utrecht University, Budapestlaan 4, 3584 CD Utrecht, Netherlands; Faculty of Earth and Life Sciences, Department of Petrology, Vrije Universiteit, De Boelelaan 1085, 1081 HV, Amsterdam, Netherlands 7033 Mathematical models; Minerals; Nickel; Seismology; Silicon; Volcanoes, Magmas; Mantle; Pyroxene; Recycled oceanic crusts, Basalt, mineral; nickel; silicon, basalt; mantle; petrogenesis; petrology, article; basalt; model; plume; priority journal; sea; United States; volcano, Hawaiian Islands; oceanic regions; Pacific islands; Pacific Ocean; World https://www.scopus.com/inward/record.uri?eid=2-s2.0-16844372977&doi=10.1038%2fnature03411&partnerID=40&md5=82fd9665dc87eac7423b1b5fc7ab8717 cited By 873 A.V. Sobolev A.W. Hofmann S.V. Sobolev I.K. Nikogosian article Walton2005 The Hawaii Scientific Drilling Project 2 Phase 1 core permits study of each stage of alteration of basalt glass during burial because stages of the process are separated vertically. Previous work has shown that alteration of hyaloclastite occurs progressively. The latest stage observed in the Phase 1 core involves marginal replacement of sideromelane in shards with palagonite while simultaneously forming chabazite in pores. The basic reaction at this stage is sideromelane + components from pore waters = palagonite + chabazite + components to pore waters. Mass balance calculations show that Fe was virtually immobile in this process, being retained in palagonite. Na, Ca, Ba, P, Al, and Si were lost during palagonitization and not fully consumed in making chabazite. Mg was lost during palagonitization but retained elsewhere in smectite. K, Rb, and Sr were extracted from pore waters and enriched in the sum of the alteration products. The amount of enrichment depended upon the amount of chabazite present, which depended upon the porosity when chabazite formed. Ti, Y, U, Zr, Nb, REE, and Th were enriched in palagonite, compared to sideromelane, but were absent in chabazite. Mass balance of all phases for the entire alteration process (including earlier stages) was not possible because poorly consolidated samples do not yield accurate modal values of phases, trace element analysis of smectite was not possible, and exchange with lavas and intrusions in the succession cannot be evaluated. Calculations indicate that too little of major oxides, except Na2O, was released during palagonitization to account for the amount of smectite observed in hyaloclastites. The results of this study, and several others published in the literature, indicate that under various circumstances palagonitization will consume particular elements from pore fluid or release them to it. Such mobility implies that the hydrology of the particular system and the composition of the dissolved solids in the pore water will control whether palagonitization is a source or sink of elements. The potential exists that palagonitization of basalt glass is an important source or sink of elements for seawater and fluids circulating in the ocean crust. Copyright 2005 by the American Geophysical Union. 2005 English 15252027 10.1029/2004GC000903 Geochemistry, Geophysics, Geosystems 6 Department of Geology, University of Kansas, 120 Lindley Hall, 1475 Jayhawk Boulevard, Lawrence, KS 66045, United States; Department of Geology, University of California, Davis, One Shields Boulevard, Davis, CA 95616-8605, United States 9 https://www.scopus.com/inward/record.uri?eid=2-s2.0-34548488663&doi=10.1029%2f2004GC000903&partnerID=40&md5=d3feaf18965eed8fbcc1353632fd3dc9 cited By 34 A.W. Walton P. Schiffman G.L. MacPherson article Seaman2004 H2O, CO2, S, Cl, and F concentrations are reported for 556 glasses from the submarine section of the 1999 phase of HSDP drilling in Hilo, Hawaii, providing a high-resolution record of magmatic volatiles over ∼200 kyr of a Hawaiian volcano's lifetime. Glasses range from undegassed to having lost significant volatiles at near-atmospheric pressure. Nearly all hyaloclastite glasses are degassed, compatible with formation from subaerial lavas that fragmented on entering the ocean and were transported by gravity flows down the volcano flank. Most pillows are undegassed, indicating submarine eruption. The shallowest pillows and most massive lavas are degassed, suggesting formation by subaerial flows that penetrated the shoreline and flowed some distance under water. Some pillow rim glasses have H2O and S contents indicating degassing but elevated CO2 contents that correlate with depth in the core; these tend to be more fractionated and could have formed by mixing of degassed, fractionated magmas with undegassed magmas during magma chamber overturn or by resorption of rising CO2-rich bubbles by degassed magmas. Intrusive glasses are undegassed and have CO2 contents similar to adjacent pillows, indicating intrusion shallow in the volcanic edifice. Cl correlates weakly with H2O and S, suggesting loss during low-pressure degassing, although most samples appear contaminated by seawater-derived components. F behaves as an involatile incompatible element. Fractionation trends were modeled using MELTS. Degassed glasses require fractionation at PH2o ≈ 5-10 bars. Undegassed low-SiO2 glasses require fractionation at PH2O ≈ 50 bars. Undegassed and partially degassed high-SiO2 glasses can be modeled by coupled crystallization and degassing. Eruption depths of undegassed pillows can be calculated from their volatile contents assuming vapor saturation. The amount of subsidence can be determined from the difference between this depth and the sample's depth in the core. Assuming subsidence at 2.5 mm/y, the amount of subsidence suggests ages of ∼500 ka for samples from the lower 750 m of the core, consistent with radiometric ages. H2O contents of undegassed low-SiO2 HSDP2 glasses are systematically higher than those of high-SiO2 glasses, and their H2O/K2O and H 2O/Ce ratios are higher than typical tholeiitic pillow rim glasses from Hawaiian volcanoes. Copyright 2004 by the American Geophysical Union. Article 2004 English 15252027 10.1029/2003GC000596 Geochemistry, Geophysics, Geosystems 5 9 https://www.scopus.com/inward/record.uri?eid=2-s2.0-33644618820&doi=10.1029%2f2003GC000596&partnerID=40&md5=81a8f586ecf7b71b9339f042e0e3782f Cited by: 46; All Open Access, Green Open Access Caroline Seaman Sarah Bean Sherman Michael O. Garcia Michael B. Baker Brian Balta Edward Stolper article Ribe2004793 The sea floor around the Hawaiian island chain is unusually shallow. New seismic evidence suggests that this up-raised 'swell' is partly due to heating and thinning of the lithosphere beneath. 2004 English 00280836 10.1038/427793a Nature 427 793-795 Inst. de Physique du Globe de Paris, 4 Place Jussieu, Paris 75252 Cedex 05, France 6977 Earth atmosphere; Sea level; Seismology, Lithosphere, Oceanography, crustal thickness; seafloor, asthenospheric upwelling; earthquake; geology; gravity; heat transfer; priority journal; short survey; United States, Hawaiian Islands; Pacific islands; Pacific Ocean, Hawaiia https://www.scopus.com/inward/record.uri?eid=2-s2.0-1542378980&doi=10.1038%2f427793a&partnerID=40&md5=fb91a782d85a30d53d9b6d9e60c2612d cited By 11 N.M. Ribe article Li2004827 The volcanism responsible for creating the chain of the Hawaiian islands and seamounts is believed to mark the passage of the oceanic lithosphere over a mantle plume. In this picture hot material rises from great depth within a fixed narrow conduit to the surface, penetrating the moving lithosphere. Although a number of models describe possible plume-lithosphere interactions, seismic imaging techniques have not had sufficient resolution to distinguish between them. Here we apply the S-wave 'receiver function' technique to data of three permanent seismic broadband stations on the Hawaiian islands, to map the thickness of the underlying lithosphere. We find that under Big Island the lithosphere is 100-110 km thick, as expected for an oceanic plate 90-100 million years old that is not modified by a plume. But the lithosphere thins gradually along the island chain to about 50-60 km below Kauai. The width of the thinning is about 300 km. In this zone, well within the larger-scale topographic swell, we infer that the rejuvenation model (where the plume thins the lithosphere) is operative; however, the larger-scale topographic swell is probably supported dynamically. 2004 English 00280836 10.1038/nature02349 Nature 427 827-829 GeoForschungsZentrum Potsdam, Telegrafenberg, 14473 Potsdam, Germany; Freie Universität Berlin, FR Geophysik, Malteserstrasse 74-100, 12249 Berlin, Germany 6977 Earth atmosphere; Imaging systems; Seismology; Surface topography, Lithosphere, Oceanography, crustal thickness; lithosphere; mantle plume; seismic tomography; volcanism, article; atmosphere; heating; imaging system; island (geological); lithosphere; mechanics; plume; priority journal; sea; signal detection; temperature measurement; thickness; topography; United States; volcano, Hawaiian Islands; Pacific islands; Pacific Ocean, Hawaiia https://www.scopus.com/inward/record.uri?eid=2-s2.0-1542319094&doi=10.1038%2fnature02349&partnerID=40&md5=cdb739f9cedb4f8918a4d08ada1ce0dd cited By 219 X. Li R. Kind X. Yuan I. Wölbern W. Hanka article Kurz2004 This paper presents new magmatic helium isotopic compositions in a suite of lavas from phase II of the Hawaiian Scientific Drilling Project (HSDP2) core, which sampled Mauna Kea volcano to a maximum depth of 3098 m below sea level. Most of the measurements were performed by in vacuo crushing of olivine phenocrysts, but include submarine pillow glasses from the 2200 to 2500 meter depth interval, and orthopyroxene phenocrysts from an intrusive at 1880 m. The magmatic 3He/4He ratios range from 6 to 24.7 times atmospheric (Ra), which significantly extends the range of values for Mauna Kea volcano. The 3He/4He ratios are lowest (i.e., close to MORB values of ∼8 Ra) near the top of the Mauna Kea section and rise slowly, to 10-12 Ra, at 1000 m below sea level, consistent with results from the HSDP1 core. At depths greater than 1000 m in the core, primarily in the submarine lavas, there are brief periods when the 3He/4He ratios are higher than 14.5 Ra, always returning to a baseline value. Twelve such excursions were identified in the core; all but one are in the submarine section, and most (7) are in the deepest section, at depths of 1950 to 3070 m. The baseline 3He/4He value rises from 10-12 Ra near 1000 m depth to 12-14 Ra at 3000 m. The helium spikes are found only in lavas that are older than 380 Ka in age, based on an age model derived from Ar-Ar data (W. D. Sharp et al., manuscript in preparation, 2003). Excluding the excursions defined by single lava flows (3) and intrusive units (3), the average spike duration is approximately 15 (±9) Ka (n = 6). The high 3He/4He spikes are interpreted as pulses of magma from the center of the actively upwelling Hawaiian hot spot. The short duration of the high 3He/4He excursions suggests that Mauna Kea was never directly over high the 3He/4He component of the plume (during the HSDP2 eruptive period), presumed to be the plume center. Assuming that the Mauna Kea helium spikes result from melting of heterogeneities within the plume, their short duration implies that the length scales of heterogeneities in the solid upwelling mantle are between 60 m and 12 km (for upwelling rates of 2 to 40 cm/yr). The high 3He/4He are associated with high 208Pb/204Pb, and relatively low 143Nd/144Nd, Zr/Nb, and SiO2. The correlations with major elements, trace elements and isotopes demonstrate that helium is coupled to the other geochemical variations, and that the Mauna Kea isotopic variability is caused by heterogeneities within the upwelling plume. Copyright 2004 by the American Geophysical Union. Article 2004 English 15252027 10.1029/2002GC000439 Geochemistry, Geophysics, Geosystems 5 4 https://www.scopus.com/inward/record.uri?eid=2-s2.0-16844379937&doi=10.1029%2f2002GC000439&partnerID=40&md5=f51cb57bcea6fb8eec35000eb297146c Cited by: 104; All Open Access, Green Open Access Mark D. Kurz Joshua Curtice Dempsey E. Lott III Andy Solow article Stolper2004 The Hawaii Scientific Drilling Project recovered-3 km of basalt by coring into the flank of Mauna Kea volcano at Hilo, Hawaii. Rocks recovered from deeper than-1 km were deposited below sea level and contain considerable fresh glass. We report electron microprobe analyses of 531 glasses from the submarine section of the core, providing a high-resolution record of petrogenesis over ca. 200 Kyr of shield building of a Hawaiian volcano. Nearly all the submarine glasses are tholeiitic. SiO2 contents span a significant range but are bimodally distributed, leading to the identification of low-SiO2 and high-SiO2 magma series that encompass most samples. The two groups are also generally distinguishable using other major and minor elements and certain isotopic and incompatible trace element ratios. On the basis of distributions of high-and low-SiO2 glasses, the submarine section of the core is divided into four zones. In zone 1 (1079-1950 mbsl), most samples are degassed high-SiO2 hyaloclastites and massive lavas, but there are narrow intervals of low-SiO2 hyaloclastites. Zone 2 (-1950-2233 mbsl), a zone of degassed pillows and hyaloclastites, displays a continuous decrease in silica content from bottom to top. In zone 3 (2233-2481 mbsl), nearly all samples are undegassed low-SiO2 pillows. In zone 4 (2481-3098 mbsl), samples are mostly high-SiO2 undegassed pillows and degassed hyaloclastites. This zone also contains most of the intrusive units in the core, all of which are undegassed and most of which are low-SiO 2. Phase equilibrium data suggest that parental magmas of the low-SiO2 suite could be produced by partial melting of fertile peridotite at 30-40 kbar. Although the high-SiO2 parents could have equilibrated with harzburgite at 15-20 kbar, they could have been produced neither simply by higher degrees of melting of the sources of the low-SiO 2 parents nor by mixing of known dacitic melts of pyroxenite/eclogite with the low-SiO2 parents. Our hypothesis for the relationship between these magma types is that as the low-SiO2 magmas ascended from their sources, they interacted chemically and thermally with overlying peridotites, resulting in dissolution of orthopyroxene and clinopyroxene and precipitation of olivine, thereby generating high-SiO2 magmas. There are glasses with CaO, Al2O3, and SiO2 contents slightly elevated relative to most low-SiO2 samples; we suggest that these differences reflect involvement of pyroxene-rich lithologies in the petrogenesis of the CaO-Al2O3-enriched glasses. There is also a small group of low-SiO2 glasses distinguished by elevated K2O and CaO contents; the sources of these samples may have been enriched in slab-derived fluid/melts. Low-SiO2 glasses from the top of zone 3 (2233-2280 mbsl) are more alkaline, more fractionated, and incompatible-element-enriched relative to other glasses from zone 3. This excursion at the top of zone 3, which is abruptly overlain by more silica-rich tholeiitic magmas, is reminiscent of the end of Mauna Kea shield building higher in the core. Copyright 2004 by the American Geophysical Union. Article 2004 English 15252027 10.1029/2003GC000553 Geochemistry, Geophysics, Geosystems 5 Division of Geological and Planetary Sciences, California Institute of Technology, MS 170-25, Pasadena, CA 91125, United States; Department of Geology and Geophysics, University OfHawaii at Manoa, 2525 Correa Road, Honolulu, HI 96822, United States 7 https://www.scopus.com/inward/record.uri?eid=2-s2.0-22444435099&doi=10.1029%2f2003GC000553&partnerID=40&md5=09ce93961c70f63ad62b6e3c95adba1b cited By 94 E. Stolper S. Sherman M. Garcia M. Baker C. Seaman article Helm-Clark20043 This paper concerns the interpretation of borehole geophysical data from basalt sequences, especially continental basalt sequences that host aquifers. Based on modifications of the rules used for interpreting borehole data from sedimentary rocks, new rules are proposed to identify the internal stratigraphy, aquifer boundaries, and alteration features in continental basalts.The value of several wireline tools is critiqued. Natural gamma logs have limited utility in basalt sequences unless anomalously high-potassium or low-potassium basalt flows and/or sedimentary interbeds exist which can act as marker beds for stratigraphic correlations. Neutron logs can usually discriminate between individual flows, flow breaks and interbeds, even in unsaturated basalts. Neutron logs and temperature logs can also be used to map aquifer thickness in basalt. Gamma-gamma density logs are usually sensitive to the density contrasts between interbeds and basalt flows, and in combination with neutron and natural gamma logs are crucial for the correct interpretation of large void spaces in basalt such as collapsed lava tubes and formerly inflated pahoehoe lobes. Basalt porosity calculated from neutron, resistivity and/or gamma-gamma density logs is commonly overestimated due to the presence of hydrous alteration minerals. Velocity and resistivity logs are best at discriminating between flows in saturated conditions. Magnetic susceptibility logs may capture magnetic mineralogy variations at a finer scale than that of flows and flow breaks and therefore should always be interpreted in combination with other logs. Non-spectral neutron-gamma logs are not useful in basalt, though spectral neutron-gamma logs have been used successfully for stratigraphic correlation and to locate pollutants. Geochemical logs or the inclination of magnetic remanence provide the best data to discriminate individual flows with a basalt sequence, and thus establish an internal stratigraphy. Other tools used alone cannot provide reliable stratigraphic information, but a combination of tools may work. We recommend the combination of natural gamma, neutron, and gamma-gamma density logs in unsaturated rocks, and these logs plus velocity and resistivity logs in saturated rocks. © 2003 Published by Elsevier B.V. 2004 English 09269851 10.1016/j.jappgeo.2003.06.003 Journal of Applied Geophysics 55 Elsevier 3-38 Department of Geosciences, Idaho State University, Pocatello, ID 83209-8072, United States; Idaho Natl. Eng./Environ.Lab., P.O. Box 1625, Idaho Falls, ID 83415, United States 1-2 Aquifers; Basalt; Boreholes; Magnetic susceptibility; Remanence; Sedimentary rocks, Magnetic mineralogy, Stratigraphy, aquifer; basalt; borehole geophysics; groundwater exploration; mineral alteration; stratigraphy https://www.scopus.com/inward/record.uri?eid=2-s2.0-0347682435&doi=10.1016%2fj.jappgeo.2003.06.003&partnerID=40&md5=65487e77453c2974052bc7941a93dd95 cited By 40 C.M. Helm-Clark D.W. Rodgers R.P. Smith article Rhodes2004 This paper presents major and trace element compositions oflavas from the entire 3098 m stratigraphic section sampled by phase-2 of the Hawaii Scientific Drilling Project. The upper 245 m are lavas from Mauna Loa volcano, and the lower 2853 m are lavas and volcanoclastic rocks from Mauna Kea volcano. These intervals are inferred to represent about 100 ka and 400 ka respectively of the eruptive history of the two volcanoes. The Mauna Loa tholeiites tend to be higher in SiO2 and lower in total iron, TiO2, alkalis, and incompatible elements at a given MgO content than Mauna Kea lavas. The transition from Mauna Loa to Mauna Kea lavas is all the more pronounced because the Mauna Loa tholeiites overlie a thin sequence of postshield Mauna Kea alkalic to transitional tholeiitic lavas. The Mauna Loa tholeiites display well- developed coherent trends with MgO that are indistinguishable in most respects from modern lavas. With depth, however, there is a slight decline in incompatible element abundances, and small shifts to depleted isotopic ratios. These characteristics suggest small changes in melt production and source components over time, superimposed on shallow melt segregation. The Mauna Kea section is subdivided into a thin, upper 107 m sequence of postshield tholeiites, transitional tholeiites and alkali basalts of the Hamakua volcanics, overlying four tholeiitic magma types that are intercalated throughout the rest of the core. These four magma types are recognized on the basis of MgO-normalized SiO2 and Zr/Nb values. Type-1 lavas (high SiO 2 and Zr/Nb) are ubiquitous below the postshield lavas and are the dominant magma type on Mauna Kea. They are inter-layered with the other three lava types. Type-2 lavas (low SiO2 but high Zr/Nb) are found only in the upper core, and especially above 850 m. Type-3 lavas (low SiO2 and Zr/Nb) are very similar to tholeiites from Loihi volcano and are present only below 1974 m. There are only 3 discrete samples of type-4 lavas (high SiO2 and low Zr/Nb), which are present in the upper and lower core. The differences between these magma types are inferred to reflect changes in melt production, depth of melt segregation, and differences in plume source components over about 400 ka of Mauna Kea's eruptive history. At the start of this record, eruption rates were high, and two distinct tholeiitic magmas (type-1 and 3) were erupting concurrently. These two magmas require two distinct source components, one similar to that of modern Loihi tholeiites and the other close to that of Kilauea magmas. Subsequently, the Loihi- like source of the type-3 magmas was exhausted, and these lavas are absent from the remainder of the core. For the next 200 ka or so, the eruptive sequence consists of inter-layered type-1 and -2 lavas that are derived from a common Mauna Kea source, the major difference between the two being the depth at which the melts segregated from the source. At around 440 ka (corresponding with the transition in the core from submarine to subaerial lavas) eruption rates began to decline and low-MgO lavas are suddenly much more abundant in the record. Continuing gradual decline in melting and eruption rates was accompanied by a decline in normalized SiO2 content of the type-1 magmas, and the eventual onset of postshield magmatism. Copyright 2004 by the American Geophysical Union. Article 2004 English 15252027 10.1029/2002GC000434 Geochemistry, Geophysics, Geosystems 5 3 https://www.scopus.com/inward/record.uri?eid=2-s2.0-34249790169&doi=10.1029%2f2002GC000434&partnerID=40&md5=db50868a981f434eda344354f4b635b6 Cited by: 146; All Open Access, Bronze Open Access J.M. Rhodes M.J. Vollinger article Wang2003 Oxygen isotope ratios were measured in olivine phenocrysts (̃1 mm diameter), olivine microphenocrysts (generally ̃100-200 mm diameter), glass, and/or matrix from 89 samples collected from depths down to 3079.7 m in the second, and main, HSDP core (HSDP-2). Olivine phenocrysts from 11 samples from Mauna Loa and 34 samples from the submarine section of Mauna Kea volcano have δ18O values that are similar to one another (5.11 ± 0.10%, 1s, for Mauna Loa; 5.01 ± 0.07%, for submarine Mauna Kea) and within the range of values typical of olivines from oceanic basalts (δ18O of ̃5.0 to 5.2%). In contrast, δ18O values of olivine phenocrysts from 20 samples taken from the subaerial section of Mauna Kea volcano (278 to 1037 mbsl) average 4.79 ± 0.13%. Microphenocrysts in both the subaerial (n = 2) and submarine (n = 24) sections of Mauna Kea are on averagẽ0.2% lower in δ18O than phenocrysts within the same stratigraphic interval; those in submarine Mauna Kea lavas have an average δ18O of 4.83 ± 0.11%. Microphenocrysts in submarine Mauna Kea lavas and phencrysts in Mauna Loa lavas are the only population of olivines considered in this study that are typically in oxygen isotope exchange equilibrium with coexisting glass or groundmass. These data confirm the previous observation that the stratigraphic boundary between Mauna Loa and Mauna Kea lavas defines a shift from "normal" to unusually low δ18O values. Significantly, they also document that the distinctive 18O-depleted character of subaerial Mauna Kea lavas is absent in phenocrysts of submarine Mauna Kea lavas. Several lines of evidence suggest that little if any of the observed variations in δ18O can be attributed to subsolidus alteration or equilibrium fractionations accompanying partial melting or crystallization. Instead, they reflect variable proportions of an 18O-depleted source component or contaminant from the lithosphere and/or volcanic edifice that is absent in or only a trace constituent of subaerial Mauna Loa lavas, a minor component of submarine Mauna Kea lavas, and a major component of subaerial Mauna Kea lavas. Relationships between the δ18O of phenocrysts, microphenocrysts, and glass or groundmass indicate that this component (when present) was added over the course of crystallization-differentiation. This process must have taken place in the lithosphere and most likely at depths of between ̃5 and 15 km. We conclude that the low-δ18O component is either a contaminant from the volcanic edifice that was sampled in increasingly greater proportions as the volcano drifted off the center of the Hawaiian plume or a partial melt of low-δ18O, hydrothermally altered perdotites in the shallow Pacific lithosphere that increasingly contributed to Mauna Kea lavas near end of the volcano's shield building stage. The first of these alternatives is favored by the difference in δ18O between subaerial and submarine Mauna Kea lavas, whereas the second is favored by systematic differences in radiogenic and trace element composition between higher and lower δ18O lavas. Copyright 2003 by the American Geophysical Union. 2003 English 15252027 10.1029/2002GC000406 Geochemistry, Geophysics, Geosystems 4 Division of Geological and Planetary Sciences, California Institute of Technology, M/C 100-23, Pasadena, CA 91125, United States 8 https://www.scopus.com/inward/record.uri?eid=2-s2.0-21644473331&doi=10.1029%2f2002GC000406&partnerID=40&md5=fa83ab9c65a9d4aeb7480cabab67f3a5 cited By 31 Z. Wang N.E. Kitchen J.M. Eiler article Büttner200323 The objectives of this paper are an understanding of the thermal and hydraulic field because of a negative temperature gradient and cold temperatures in the 1-km-deep borehole of the Hawaiian Scientific Drilling Project (HSDP), located near the coast line. The temperature pattern is attributed to a superposition of thermal and hydraulic processes. In the deeper borehole (HSDP-2, depth 3.1 km) detailed temperature monitoring was performed. Temperature measurements reveal two different thermal regimes. The upper part is characterised by cold temperatures and a negative temperature gradient similar to those observed in the shallow pilot borehole. Below 1100 m, increasing temperatures are observed. Different processes, such as topographically driven groundwater flow, ingress of salt water and conductive heat flow are investigated by numerical modeling. A pure conductive scenario fails to match the temperature measurements, implying that both borehole sections are overprinted by advective conditions. Coupled fluid and heat flow modeling with solute transport yield results that agree with observed temperatures. The results of these simulations suggest that meteoric water flow from the mountain range controls the thermal conditions in the upper part of the borehole. Below this level, the thermal regime is additionally affected by circulation of salt water from the nearby ocean. Each of these flow systems has been observed at other locations: topographically driven fresh water at locations with pronounced topography and ingress of salt water is typical for islands or coastal areas. At Hawaii, they coincide and influence each other, resulting in a salt water interface occurring at greater depth than expected. © 2003 Elsevier B.V. All rights reserved. Article 2003 English 00401951 10.1016/S0040-1951(03)00197-5 Tectonophysics 371 Elsevier B.V. 23 – 40 1-4 Hawaii; Mauna Kea; United States; borehole; heat flow; heat transfer; hydraulic property; temperature gradient; thermal structure https://www.scopus.com/inward/record.uri?eid=2-s2.0-0042328346&doi=10.1016%2fS0040-1951%2803%2900197-5&partnerID=40&md5=606285c48d0179e06af7db5641176264 Cited by: 12 Grit Büttner Ernst Huenges article Eisele2003 [1] We analyzed Pb isotopic compositions of 50 samples from the HSDP-2 drill hole, covering the time interval 180 to 550 kyr B.P. in the stratigraphic record of Mauna Kea. All analyses were corrected for instrumental bias using a triple-spike technique. The aims of this study are to document temporal changes in sources contributing to Mauna Kea and to investigate how these may relate to the chemical structure of the Hawaiian plume. Lead isotopic compositions of the lavas have 206Pb/204Pb ratios ranging from 18.41 to 18.63, 207Pb/204Pb from 15.47 to 15.49, and 208Pb/ 204Pb from 37.97 to 38.22. In 207Pb/204Pb- 206Pb/204Pb space, the samples display a broad linear array, while three distinct arrays are found in 208Pb/ 204Pb-206Pb/204Pb space. These arrays can clearly be distinguished by their 208Pb/204Pb ratios and are referred to as "Kea-lo8," "Kea-mid8," and "Kea-hi8." The 206Pb/204Pb isotope ratios exhibit rapid shifts by ̃0.2 over 100 m depth intervals, and jumps from one Pb isotope array to another and back in less than ̃100 m depth. Despite these rapid Pb isotope fluctuations, a particular Pb isotope array dominates over periods of several tens to hundreds of kiloyears. We interpret the Pb isotope arrays found in HSDP-2 in terms of mixing of end-members lying along the radiogenic and unradiogenic extensions of the arrays. At the radiogenic extension the three HSDP-2 arrays converge to a common end-member. The lower extensions of the arrays diverge in three directions, each with different 208Pb/ 204Pb ratios. This topology suggests that the HSDP-2 arrays were produced by mixing of at least four end-members. The origin of these end-members was investigated using Monte Carlo simulations of a Pb isotope evolution model. The simulations suggest that the common radiogenic end-member of the three Pb isotope arrays contains material with elevated m values and has a relatively young age (<1.5 Ga). Such a signature can be plausibly interpreted in terms of the presence of recycled oceanic crust in the source. The HSDP-2 Kea-lo8, Keamid8, and Kea-hi8 Pb isotope arrays dominate over different time periods and can be related to the displacement of Mauna Kea relative to the plume center over time. The Kea-lo8 array is present between ̃180 and 370 ka and samples more peripheral parts of the plume, while the Kea-mid8 and Kea-hi8 arrays occur in the deeper parts of the core (̃370 to 550 kyr ago), when Mauna Kea was closer to the plume center. Over the time intervals when each array dominates, we derive corresponding "lengths" of materials in the source by integrating the estimated upwelling velocity across the plume. These calculations suggest Pb isotope heterogeneities of at least several tens of kilometers in vertical length within the Hawaiian plume. The Pb isotope arrays may correspond to relatively small-scale heterogeneities derived from the D″ layer in the lower mantle. © 2003 by the American Geophysical Union. Article 2003 English 15252027 10.1029/2002GC000339 Geochemistry, Geophysics, Geosystems 4 5 https://www.scopus.com/inward/record.uri?eid=2-s2.0-2142757212&doi=10.1029%2f2002GC000339&partnerID=40&md5=d28bdb295b3e7b3104019db9b1430df4 Cited by: 138; All Open Access, Bronze Open Access Jürgen Eisele Wafa Abouchami Stephen J.G. Galer Albrecht W. Hofmann article Feigenson2003 The rare earth element (REE) concentrations of lavas from the Hawaiian Scientific Drilling Project (HSDP2) can be used to provide additional constraints on phase equilibria and the nature of the Hawaiian source. Major element analyses separate Mauna Kea lavas into two distinct populations, a high-silica and a low-silica suite. The low-silica samples can be separated stratigraphically into an upper low-silica alkalic series and a low-silica tholeiitic group that occurs deeper in the section. These contrasting groups could result from different extents of source partial fusion, or lithologically distinct source regions, or some combination of both factors. Petrologic modeling is performed to calculate that primary magma compositions contain about 20% MgO, and can be formed by 8-15% melting of a depleted mantle source for low-silica alkalic and high-silica lavas, respectively. The low-silica tholeiites could be generated by higher degrees of melting of a more fertile source. REE ratios and various isotopic systems reinforce the division of the low-SiO2 samples into the upper alkalic series, characterized by high Gd/Yb, and the deeper low-silica tholeiitic group, with low Gd/Yb. REE inverse modeling of fractionation-corrected basalts is consistent with lower degrees of melting to generate the late-stage alkalic lavas, with garnet present as a residual phase. The relatively constant Gd/Yb for low-silica tholeiites suggests that garnet is not an important residual phase during partial melting, implying higher extents of melting. The low-silica tholeiites are characterized by relatively enriched isotopic signatures that are consistent with contributions from a primitive source or from recycled subduction components. High 3He/4He associated with the lowsilica lavas could derive from primitive mantle, mass transfer from the core, or from a refractory lithospheric contribution to a recycled subduction package. However, the combination of major element, REE and isotopic data suggests that the deeper low-silica suite is sampling the relatively fertile, interior part of the Hawaiian plume, whereas the high-silica lavas are extracted from the more depleted periphery; later alkalic lavas are generated from a depleted source as the volcano moves off the hot spot. © 2003 by the American Geophysical Union. 2003 English 15252027 10.1029/2001GC000271 Geochemistry, Geophysics, Geosystems 4 Department of Geological Sciences, Rutgers University, 610 Taylor Road, Piscataway, NJ 08854, United States 2 https://www.scopus.com/inward/record.uri?eid=2-s2.0-0141828869&doi=10.1029%2f2001GC000271&partnerID=40&md5=19955926da5f90d4601cbb82c6ff5db2 cited By 43 M.D. Feigenson L.L. Bolge M.J. Carr C.T. Herzberg article Steveling2003 A quasi-continuous magnetic log has been obtained in the Hawaii Scientific Drilling Project 2 (HSDP-2) between 600 m and 1800 m, which corresponds to a time interval of approximately 350 ka to 480 ka. A tri-axial borehole magnetometer was employed to measure the horizontal and vertical magnetic fields. Measurements were taken in downhole and uphole runs, with a good correlation between the two. In a first step the logs were corrected for the transfer function of the employed low-pass filter and then for the logging depths. To calculate rock magnetizations from magnetic components, we used a multidisk cylindrical model for the penetrated rocks. The disk thickness corresponds with 0.1 m to the logging sampling rate. Magnetic borehole logging in the HSDP-2 hole has established the following: Massive lava flows can be distinguished from those with prevailing hyaloclastites and enables us to supplement the lithology, especially in depth intervals with poor core recovery. The inclinations of rock magnetization derived from the magnetic log agree well with those measured in core samples from HSDP-2 hole. The same applies to magnitudes of magnetizations from logging, as the sum of induced and remanent magnetizations, with laboratory determinations of the remanent magnetizations of core samples. We observe a distinct discrepancy between the local present-day geocentric axial dipole (GAD) inclination of 35.6° and the mean logging inclination of 22.7°. Furthermore, a systematic inclination decrease with depth is observed. Logging and core inclinations in HSDP-2 can be brought into agreement with core inclinations in the HSDP-1 pilot hole by shifting depths of HSDP-1 100 m downward. The correlation of inclination data between the two boreholes and the known age-depth relation of HSDP-1 is used to reexamine the "age versus depth" model curve for Mauna Kea of Sharp et al. (manuscript in preparation, 2003). We identify tentatively two logged inclination minima with excursion of the geomagnetic field in Brunhes, namely, "Levantine" at 360-370 ka and "Unknown" at 400-420 ka. © 2003 by the American Geophysical Union. 2003 English 15252027 10.1029/2002GC000330 Geochemistry, Geophysics, Geosystems 4 Institut für Geophysik, Herzberger Landstrasse 180, 37075 Goettingen, Germany; BGR, Stilleweg 2, 30655 Hannover, Germany 4 https://www.scopus.com/inward/record.uri?eid=2-s2.0-36048943437&doi=10.1029%2f2002GC000330&partnerID=40&md5=6947172fec0e9dfc898aed531c18380b cited By 10 E. Steveling J.B. Stoll M. Leven article Tauxe2003 Paleointensity estimates based on the high quality Thellier-Thellier data from the early Brunhes (420-780 ka) are rare (only 30 in the published literature). The Second Hawaiian Scientific Drilling Project (HSDP2) drill hole recovered submarine volcanics spanning the approximate time period of 420-550 ka. These are of particular interest for absolute paleointensity studies owing to the abundance of fresh submarine basaltic glass, which can preserve an excellent record of ancient geomagnetic field intensity. We present here new results of Thellier-Thellier paleointensity experiments that nearly double the number of reliable paleointensity data available for the early Brunhes. We also show that the magnetizations of the associated submarine basalts are dominated by viscous magnetizations and therefore do not reflect the true ancient geomagnetic field intensity at the time of extrusion. The viscous contamination is particularly severe because of a combination of low blocking temperatures in the basalts and relatively high temperatures in the deeper parts of the drill core. Our new data, when placed on the approximate timescale available for HSDP and HSDP2, are at odds with other contemporaneous paleointensity data. The discrepancy can be reconciled by adjusting the HSDP timescales to be younger by about 35 kyr. © 2003 by the American Geophysical Union. Article 2003 English 15252027 10.1029/2001GC000276 Geochemistry, Geophysics, Geosystems 4 Blackwell Publishing Ltd Scripps Institution of Oceanography, University of California, San Diego, La Jolla, CA 92093, United States; U. S. Geological Survey, Golden, Box 25046, MS966, DFC, Denver, CO 80225, United States 2 https://www.scopus.com/inward/record.uri?eid=2-s2.0-1542493807&doi=10.1029%2f2001GC000276&partnerID=40&md5=9a254bc2a7ea752bfd95670c25990959 cited By 29 L. Tauxe J.J. Love article Chan2003 [1] We determined lithium isotopic compositions of Mauna Loa and Mauna Kea basalts from the 3.1 km drill hole of the Hawaiian Scientific Drilling Project (HSDP); for comparison Li isotopic ratios were also determined for basalts from Koolau volcano. These two suites of samples define geochemical extremes in the range of Hawaiian shield lavas. The 400 Ka record of Mauna Kea in the HSDP core shows temporal fluctuations between low δ7Li (̃4% relative to the L-SVEC standard) and high δ7Li (5-6%), suggesting that the source components in the Hawaiian plume are heterogeneous in Li isotopic composition. Based on SiO2 content and isotopic ratios of He, Li, Nd, Hf and Pb, three geochemical groups are identified in Mauna Kea lavas. Mauna Kea basalts between 1900 and 2500 mbsl have relatively low δ7Li of about 4%. They are low SiO2 lavas distinguished by the highest 3He/4He and 208Pb/204Pb, and low 176Hf/ 177Hf and 143Nd/144Nd. Like basalt from Loihi seamount, this Mauna Kea group is considered to originate from the core of the plume. Above 1900 mbsl, high δ7Li lavas with high SiO 2 contents appear in both the submarine and subaerial sections. They are marked by low 3He/4He and high 176Hf/177Hf. The 7Li-rich signature of some samples (δ7Li up to 5.7) is indicative of recycled oceanic crust in the plume. This magma group defines the Kea component. The low SiO2 lavas in the subaerial section have low δ7Li (̃4%), 3He/4He and 208Pb/204Pb. Their δ7Li values overlap the range of δ7Li in unaltered mid-ocean ridge basalt (MORB) and are consistent with upper mantle material entrained by the plume or contamination of plume-derived magmas by the Pacific lithosphere. The δ7Li of Koolau lavas mostly fall within the range of 4.5 ± 0.3%. Exceptions are two samples that have δ7Li of 2-3%. The lightest isotopic values may indicate subducted Li that was isotopically fractionated during slab dehydration. In contrast to other isotopic systems, most Koolau samples, however, resemble Mauna Kea samples in Li isotopic composition. Mauna Loa samples have δ7Li values of 3.5 to 4.9%, within the range of the Koolau and Mauna Kea lavas. Based on these data, the Loa trend volcanoes and Kea trend volcanoes have largely overlapping Li isotopic compositions. In summary, the Hawaiian plume is not highly variable in Li isotopic composition; δ7Li is typically ̃4% with perturbations by subducted components to lower and higher ratios (2.5 to 5.7%). The overlap of most Hawaiian basalt and MORB in their range of Li isotopic ratios suggests minor influence of recycled oceanic crust in the plume and perhaps similar Li isotopic ratios in the upper and lower mantle. © 2003 by the American Geophysical Union. Article 2003 English 15252027 10.1029/2002GC000365 Geochemistry, Geophysics, Geosystems 4 Department of Geology and Geophysics, Louisiana State University, Baton Rouge, LA 70803, United States; Department of Earth, Atmospheric, and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States 3 https://www.scopus.com/inward/record.uri?eid=2-s2.0-1642526103&doi=10.1029%2f2002GC000365&partnerID=40&md5=e8e66c7dc745c76e93b2ee43d2a7126d cited By 118 L.-H. Chan F.A. Frey article Althaus2003 [1] We have determined concentrations and isotopic compositions of all noble gases in olivine phenocrysts from the Hawaii Scientific Drilling Project (HSDP) drill core, comprising Mauna Loa lavas in the top 247 m and Mauna Kea lavas down to the preliminary depth of 3109 m. Our aim was to describe the long-term isotopic evolution of noble gases over a significant time fraction of the active life of a major Hawaiian volcano. The He isotopic signature displays a clear temporal trend: 3He/4He ratios increase from MORBlike 9 RA in the youngest lavas to 15 RA in the Mauna Loa section and from ̃7 RA to ̃12 RA in the subaerial Mauna Kea deposits. They remain close to 12 RA in most of the submarine Mauna Kea samples, except for a few excursions with 3He/4He ratios of up to 21 RA in borehole depths between 2000 and 2600 m. The average 3He/4He ratio of 12 RA is lower than that observed in recent eruptions of Kilauea and Loihi seamount and supports the idea of a concentrically zoned Hawaiian plume [Kurz et al., 1996]. The Ne isotopic signature does not show a temporal evolution. It remains plume-like (plotting close to the Loihi-Kilauea correlation line in a Ne three-isotope diagram) over the whole Mauna Kea section in those samples which are not dominated by air-like Ne. Maximum 20Ne/22Ne and 21Ne/22Ne ratios reach 12.10 ± 0.36 and 0.0360 ±0.0042, respectively. 40Ar/36Ar ratios vary widely between 360 and ̃3300 in the ≥1000°C release steps due to variable atmospheric contributions. In at least one sample, a 40Ar/ 36Ar ratio of 14,300 ±910 demonstrates the presence of a MORB-like Ar component. Kr and Xe isotopic compositions are atmospheric throughout. We discuss several possibilities on how to explain the isotopic trends of the noble gases and their correlation to other geochemical parameters. Simple admixture of MORB-like noble gases to the plume component cannot account for the observations. We favor a model involving early melt extraction from the outer plume sections, followed by radiogenic ingrowth and, possibly, some interaction with ambient mantle material. © 2003 by the American Geophysical Union. Article 2003 English 15252027 10.1029/2001GC000275 Geochemistry, Geophysics, Geosystems 4 Blackwell Publishing Ltd 1 https://www.scopus.com/inward/record.uri?eid=2-s2.0-28044440283&doi=10.1029%2f2001GC000275&partnerID=40&md5=da027d803303188b40c6858a397dbc7e Cited by: 16 Tilmann Althaus Samuel Niedermann article Katz2003 Hawaiian lava flows are classified as pahoehoe or ̀àa by their surface morphology. As surface morphology reflects flow emplacement conditions, the surface distribution of morphologic flow types has been used to study the evolution and eruptive history of basaltic volcanoes. We extend this analysis to the third dimension by determining the distribution of flow types in two deep drill cores, the Scientific Observation Hole-4 (SOH-4) core, drilled near Kilauea's East Rift Zone (ERZ), and the pilot hole (Kahi Puka-1 (KP-1)) for the Hawaiian Scientific Drilling Project (HSDP), drilled through distal flows from Mauna Loa and Mauna Kea. Flows are classified using both internal structures and groundmass textures, with the latter useful when identification based on mesoscopic flow features (e.g., surface morphology and vesicle content and distribution) is ambiguous. We then examine the temporal distribution of pahoehoe and ̀àa flows in proximal (SOH-4) and distal (KP-1) settings. Sequence analysis shows that the two flow types are not randomly distributed in either core but instead are strongly clustered. The proximal SOH-4 core is dominated by thin pahoehoe flows (̃60% by volume), consistent with the common occurrence of surface-fed pahoehoe flows in near-vent settings. The distal KP-1 core has a high proportion of ̀àa (̃58% by volume), although the proportion of pahoehoe and̀àa varies dramatically throughout the Mauna Kea sequence. Thick inflated pahoehoe flows dominate when the drill site was near sea level, consistent with the numerous inflated pahoehoe fields on the current coastal plains of Kilauea and Mauna Loa. ̀Àa flows are abundant when the site was far above sea level. As slope increases from the coastal plains to Mauna Kea's flank, this correlation may reflect the combined effect of long transport distances and increased slopes on flow emplacement. These results demonstrate that flow type and thickness variations in cores provide valuable information about both vent location and local site environment. Observed variations in flow type within the KP-1 core raise interesting questions about feedback between volcano evolution and flow morphology and suggest that flow type is an important variable in models of volcano growth and related models for lava flow hazard assessment. © 2003 by the American Geophysical Union. 2003 English 15252027 10.1029/2001GC000209 Geochemistry, Geophysics, Geosystems 4 Department of Geological Sciences, University of Oregon, Eugene, OR, 97403-1272, United States 2 https://www.scopus.com/inward/record.uri?eid=2-s2.0-67349099488&doi=10.1029%2f2001GC000209&partnerID=40&md5=4727a773743e2110f03c87bd688a6997 cited By 40 M.G. Katz K.V. Cashman article Janne2003 The present work reports multiple collector inductively coupled plasma mass spectrometry (MC-ICPMS) measurements of the isotopic compositions of Hf and Pb in the first 3 km of the deep core retrieved by the Hawaii Scientific Drilling Project. The measurements cover all the samples from the standard geochemical reference set, glasses from the deep hole, and replicates from the pilot hole. Both Hf and Pb are less radiogenic in Mauna Loa compared to Mauna Kea. The transition between Mauna Kea and Mauna Loa lavas in the deep core is progressive for eHf and 208Pb/204Pb, but a sharp discontinuity is observed for 208Pb*/206Pb*. There is no correlation between the alkalinity of the samples and isotopic composition. In detail, the Hf isotope compositions of samples from the pilot hole are not all identical to those of the HSDP-2 core for samples retrieved from a similar depth, suggesting that steep topography existed at the time of emplacement or that a different eruptive sequence was recorded. The strong correlation between 208Pb*/206Pb* and 3He/ 4He (He data from M. D. Kurz et al. (Rapid helium isotopic variability in Mauna Kea shield lavas from the Hawaiian Scientific Drilling Project, submitted to Geochemistry Geophysics Geosystems, 2002)) requires the episodic incorporation of a component that resembles the basalts erupted by either Kilauea or the Loihi eruptive centers (this component is referred to as K/L). The data suggest that some 500 kyr ago, Mauna Kea was tapping a mantle source similar to that tapped by Kilauea today. Isotopic variability of Pb and He cannot be accounted for by radiogenic ingrowth in a closed system, but requires the mixing of mantle source components with distinct outgassing histories. The time series of isotopic and concentration data in Mauna Kea samples spanning about 350,000 years of age indicate the recurrence of geochemical patterns in the melting column. Ignoring the most recent alkalic samples, we find that the dominant fluctuations of eHf and 207Pb/204Pb correspond to a period of 50,000 years. For La/ Yb, Zr/Nb, 87Sr/ 86Sr, 206Pb/204Pb, 207Pb/ 206Pb, and 208Pb/206Pb, a dominant period of ca. 18,000 years is obtained. Once provision is made for the existence of harmonics, the consistency between the isotopic spectrum of the pilot hole and the HDSP-2 core is very good. The input of the K/L component does not seem to be periodic. We use these recurrence intervals in conjunction with the upwelling rate deduced from buoyancy flux and seismic evidence of the maximum dimension of scatterers to constrain the radius of the Hawaiian plume conduit to be in the range of 10-50 km and the upwelling velocity to be in the range of 0.13-3 m/yr. Plausible vertical length scales of heterogeneities in the conduit are 6.5-160 km. © 2003 by the American Geophysical Union. Article 2003 English 15252027 10.1029/2002GC000340 Geochemistry, Geophysics, Geosystems 4 2 https://www.scopus.com/inward/record.uri?eid=2-s2.0-72749086414&doi=10.1029%2f2002GC000340&partnerID=40&md5=bde6696dc5ee8ae5050729f1f1b18d54 Cited by: 132; All Open Access, Bronze Open Access Blichert-Toft Janne Dominique Weis Claude Maerschalk Arnaud Agranier Francis Albarède article Tauxe2003 2003 English 15252027 10.1029/2003GC000564 Geochemistry, Geophysics, Geosystems 4 Scripps Institution of Oceanography, University of California, San Diego, CA 92093, United States; U. S. Geological Survey, Golden, Box 250460, DFC, Denver, CO, 80225, United States 5 https://www.scopus.com/inward/record.uri?eid=2-s2.0-72449194322&doi=10.1029%2f2003GC000564&partnerID=40&md5=e49e534eeeef5c623da657e4445eec79 cited By 0 L. Tauxe J.J. Love article Kontny2003 This study presents rock magnetic properties and the magnetic mineralogy of subaerial and submarine lava flows of Mauna Loa and Mauna Kea volcanoes collected from the 3109 m deep HSDP-2 drill hole in Hawaii. Three different groups of magnetic behavior are recognized in the subaerial lava flows related to the degree of high temperature oxidation during extrusion. Group 1 shows homogenous titanomagnetite with low Xmt, low Curie temperatures (TC: 100°-200°C) and weak median demagnetizing fields (&lt; 20 mT). Further subdivision into 1a and 1b subgroups is based on the low temperature behavior of magnetic susceptibility (MS) and hysteresis loops, which indicate a contribution from ferrimagnetic Cr-Al spinel below ca.-160°C in the 1b-type samples. Group 2 samples, with exsolution lamellae of ilmenite in the titanomagnetites, have higher TC (480°-580°C) and higher coercive forces (20-40 mT). Group 3, the highest oxidation stage, is characterized by titanohematite-bearing assemblages with enhanced median demagnetizing fields (35-85 mT) and a significantly different low-temperature MS behavior. MS core logging shows a systematic variation occurs in the subaerial lava flows, directly related to the degree of high temperature oxidation and their flow morphology. Aa lava flows have higher mean MS than other lava flow types. Besides these factors, MS appears to be also affected by the magma composition of the various shield-building stages. Mauna Loa subaerial lava flows generally show lower mean susceptibilities (4.6 ± 3 × 10-3 SI) than subaerial Mauna Kea lava flows (9.8 ± 5 × 10-3 SI). As submarine lava flows show no group 3 assemblages no high temperature oxidation influenced these rocks. Some hyaloclastites and pillow breccias show low MS (&lt; 1 × 10-3 SI), small amounts of nearly pure magnetite (TC = 580°C) and high coercive forces up to 110 mT suggesting single domain and/or superparamagnetic behavior. The controlling mechanism of the magnetic properties in the submarine lava units is the cooling and quenching rate of lava flows, which creates large grain size variations in titanomagnetites of varying compositions. Hydrothermal alteration, as described from ocean floor or Icelandic basalts, is not an important process that influences the magnetic properties in the ocean island basalts from the HSDP-2 drill hole. © 2003 by the American Geophysical Union. 2003 English 15252027 10.1029/2002GC000304 Geochemistry, Geophysics, Geosystems 4 Geologisch-Paläontologisches Institut, Ruprecht-Karls-Universität, Im Neuenheimer Feld 234, D-69120 Heidelberg, Germany; Institut für Geologie, Bayerische Julius-Maximilian Universität, Pleicherwall 1, D-97070 Würzburg, Germany 2 https://www.scopus.com/inward/record.uri?eid=2-s2.0-1542368966&doi=10.1029%2f2002GC000304&partnerID=40&md5=c13b9e6c6bb52cd68847d3bc31caa98e cited By 37 A. Kontny C. Vahle H. De Wall article Walton2003 [1] The core from the Hawaii Scientific Drilling Project 2 Phase 1 provides a unique opportunity for studying the low-temperature alteration processes affecting basalt in suboceanic-island environments. In hyaloclastites, which make up about one half of the lower 2 km of this core (the portion that accumulated below sea level), these processes have resulted in zones of incipient, smectitic, and palagonitic alteration. The alteration of sideromelane in these hyaloclastites has four distinct outcomes: dissolution, replacement by two different textural varieties of smectite (i.e., reddened and green grain-replacive), and conversion to palagonite. All samples show evidence of the incipient stage of alteration, suggesting that every sample passed through that zone. However, most samples that show palagonitic alteration do not also show evidence of smectitic alteration and vice versa, suggesting these two outcomes represent divergent paths of alteration. Incipient alteration (1080 to 1335 m depth) includes fracturing and mechanical reduction of porosity from 40-45% to about 20-30%; growth of one form of pore-lining smectite; dissolution of sideromelane; and formation of sideromelane-grain replacements consisting of Fe-hydroxide-strained smectite, titaniferous nodules, and tubules. DNA-specific stains and morphological features indicate that tubules are the result of microbial activity. Smectitic alteration (1405 to 1573 m) includes growth of a second variety of pore-lining smectite, pore-filling and grain-replacing smectite, and cements of phillipsite and Ca-silicate minerals. Palagonitic alteration (1573 m to the deepest samples) includes replacement of margins of shards with palagonite and growth of pore-filling chabazite. The porosity is reduced by cementation to less than 4% at 1573 m. Porosity does not decrease further down hole, nor does the thickness of palagonite rims on shards increase through the zone of palagonitic alteration. In these samples, palagonite is not an intermediate alteration product in the development of smectite. Rather, in hyaloclastites from the HSDP core, palagonite has formed after all observed smectites. Current downhole temperatures at the boundaries between the three alteration zones are in the range from 12° to 15°C, suggesting that geochemical thresholds or vital effects, not temperature conditions, control different outcomes of alteration. © 2003 by the American Geophysical Union. 2003 English 15252027 10.1029/2002GC000368 Geochemistry, Geophysics, Geosystems 4 Department of Geology, University of Kansas, 1475 Jayhawk Boulevard, Lawrence, KS 66045, United States; Department of Geology, University of California, 1 Shields Boulevard, Davis, CA 95616, United States 5 https://www.scopus.com/inward/record.uri?eid=2-s2.0-7544228116&doi=10.1029%2f2002GC000368&partnerID=40&md5=cb00df94ccd745bacbedb5b53fe56ec5 cited By 74 A.W. Walton P. Schiffman article Huang2003 [1] The temporal geochemical variations defined by lavas erupted throughout the growth of a single volcano provide important information for understanding how the Hawaiian plume works. The Hawaii Scientific Drilling Project (HSDP) sampled the shield of Mauna Kea volcano to a depth of 3100 meters below sea level during Phase 2 of the HSDP. Incompatible element abundance ratios, such as La/Yb, Sm/ Yb, Nb/Zr, and Ti/Zr, in conjunction with SiO2 abundance and radiogenic isotopic ratios, especially He and Pb, in the reference sample suites of the Mauna Kea portion of cores from Phases 1 and 2 of the HSDP define three distinct geochemical groups. The upper 550 m of Mauna Kea lavas in the Phase 2 core include the Postshield Group with eruption ages of ̃200 ka to &lt;370 ka. These lavas have relatively low SiO2 content, 3He/4He and 206Pb/204Pb, and they define a trend to relatively high La/Yb, Sm/Yb, and Nb/Zr. The eruption of these lavas coincides with migration of the Mauna Kea shield off the hot spot. As a result, extent of melting decreased, melt segregation occurred at greater depth, within the garnet stability field, and a geochemically distinct component associated with the periphery of the plume was sampled. Deeper in the Phase 2 core two other geochemical groups of lava are intercalated. One group has relatively low SiO2 abundance and high Nb/Zr Ti/Zr, 3He/4He and high 208Pb/204Pb at a given 206Pb/204Pb. These are distinctive geochemical characteristics of lavas erupted at Loihi seamount. Variations in incompatible element abundance ratios (e.g., Sm/Yb versus Nb/Zr and La/Yb versus Ti/Zr) define mixing trends between these low SiO2 lavas (Loihi-type) and lavas belonging to a high SiO2 group that are the dominant lava type in the shield part of the core (Kea-type). These two groups are presumed to reflect components intrinsic to the plume. Correlations of incompatible element abundance ratios, such as La/Nb, with radiogenic isotope ratios show that Hawaiian shields contain different proportions of geochemically distinctive components. The Koolau shield contains a recycled sedimentary component that is not present in the Mauna Kea shield. The anomalously high Ba/Th in Hawaiian lavas is inferred to be a source characteristic. Ba/Th is correlated with some radiogenic isotope ratios in Kilauea and Mauna Loa lavas, but there is no correlation in Mauna Kea lavas which range in Ba/Th by a factor of 2.6. Copyright 2003 by the American Geophysical Union. Article 2003 English 15252027 10.1029/2002GC000322 Geochemistry, Geophysics, Geosystems 4 Department of Earth, Atmospheric and Planetary Sciences, Massachusetts Institute of Technology, Cambridge, MA 02139, United States 6 https://www.scopus.com/inward/record.uri?eid=2-s2.0-0037926609&doi=10.1029%2f2002GC000322&partnerID=40&md5=638f32ef4969c896ea182af049d85a79 cited By 75 S. Huang F.A. Frey article Hurwitz2002ECV13 Temperature measurements in deep drill holes on volcano summits or upper flanks allow a quantitative analysis of groundwater induced heat transport within the edifice. We present a new temperature-depth profile from a deep well on the summit of Kilauea Volcano, Hawaii, and analyze it in conjunction with a temperature profile measured 26 years earlier. We propose two groundwater flow models to interpret the complex temperature profiles. The first is a modified confined lateral flow model (CLFM) with a continuous flux of hydrothermal fluid. In the second, transient flow model (TFM), slow conductive cooling follows a brief, advective heating event. We carry out numerical simulations to examine the timescales associated with each of the models. Results for both models are sensitive to the initial conditions, and with realistic initial conditions it takes between 750 and 1000 simulation years for either model to match the measured temperature profiles. With somewhat hotter initial conditions, results are consistent with onset of a hydrothermal plume ∼550 years ago, coincident with initiation of caldera subsidence. We show that the TFM is consistent with other data from hydrothermal systems and laboratory experiments and perhaps is more appropriate for this highly dynamic environment. The TFM implies that volcano-hydrothermal systems may be dominated by episodic events and that thermal perturbations may persist for several thousand years after hydrothermal flow has ceased. Article 2002 English 21699313 Journal of Geophysical Research: Solid Earth 107 Blackwell Publishing Ltd ECV 13–1 – 13–10 11 Hawaii; Kilauea Volcano; United States; groundwater flow; heat transfer; hydrothermal system; perturbation; transient flow; volcano; well https://www.scopus.com/inward/record.uri?eid=2-s2.0-0037542515&partnerID=40&md5=09e9685874ef9b1c8ed90cd737dc63cd Cited by: 27 Shaul Hurwitz Steven E. Ingebritsen Michael L. Sorey article Moore2001221 Density measurements of 1600 samples of core from 889 to 3097 m depth below sea level in the Hawaii Scientific Drilling Program hole near Hilo, Hawaii show marked differences between the basaltic rock types and help define stratigraphy in the hole. Water-saturated densities of subaerial lava flows (occurring above 1079 m depth) have the broadest range because of the large density variation within a single lava flow. Water-saturated densities commonly range from 2.0 to 3.0 with an average of 2.55 ± 0.24 g/cc. Dikes and sills range from 2.8 to 3.1 g/cc). Densities of hyaloclastite commonly range from 2.3 to 2.7, with an overall average of about 2.5 g/cc. The low-density of most hyaloclastite is due primarily to palagonitization of abundant glass and presence of secondary minerals in the interstices between fragments. Four principal zones of pillow lava, separated by hyaloclastite, occur in the drill core. The shallowest (1983-2136 m) is paradoxically the densest, averaging 3.01 ± 0.10 g/cc. The second (2234-2470 m) is decidedly the lightest, averaging 2.67 ± 0.13 g/cc. The third (2640-2790 m) and fourth (2918-bottom at 3097 m) are high, averaging 2.89 ± 0.17 and 2.97 ± 0.08 g/cc, respectively. The first pillow zone includes degassed pillows i.e. lava erupted on land that flowed into the sea. These pillows are poor in vesicles, because the subaerial, one-atmosphere vesicles were compressed when the flow descended to deeper water and higher pressure. The second (low-density, non-degassed) pillow zone is the most vesicle-rich, apparently because it was erupted subaqueously at a shallow depth. The higher densities of the third and fourth zones result from a low vesicularity of only a few percent and an olivine content averaging more than 5% for the third zone and about 10% for the fourth zone. The uppermost hyaloclastite extending about 400 m below the bottom of the subaerial basalt is poorly cemented and absorbs up to 6 wt% of water when immersed. Progressing downward the hyaloclastite absorbs less water and becomes better cemented. This change is apparently due to palagonitization of glass and addition of secondary minerals in the deeper older hyaloclastite, a process favored by the increase of temperature with depth. The cementation is largely complete at 1800 m depth where the temperature attains about 20°C. The zone of freshest, uncemented hyaloclastite represents the weakest rock in the drill hole and is a likely level for tectonic or landslide disruption. © 2001 Published by Elsevier Science B.V. Article 2001 English 03770273 10.1016/S0377-0273(01)00242-6 Journal of Volcanology and Geothermal Research 112 221 – 230 1-4 United States; Landslides; Stratigraphy; Thermal effects; Volcanic rocks; basalt; density; hyaloclastite; pillow lava; stratigraphy; Hyaloclastite; Volcanoes https://www.scopus.com/inward/record.uri?eid=2-s2.0-0035694617&doi=10.1016%2fS0377-0273%2801%2900242-6&partnerID=40&md5=00958742710669c478847a2692aad7f3 Cited by: 59 James G Moore article Li2000938 The volcanic edifice of the Hawaiian islands and seamounts, as well as the surrounding area of shallow sea floor known as the Hawaiian swell, are believed to result from the passage of the oceanic lithosphere over a mantle hotspot. Although geochemical and gravity observations indicate the existence of a mantle thermal plume beneath Hawaii, no direct seismic evidence for such a plume in the upper mantle has yet been found. Here we present an analysis of compressional-to-shear (P-to-S) converted seismic phases, recorded on seismograph stations on the Hawaiian islands, that indicate a zone of very low shear-wave velocity (&lt; 4 km s-1) starting at 130-140 km depth beneath the central part of the island of Hawaii and extending deeper into the upper mantle. We also find that the upper-mantle transition zone (410-660 km depth) appears to be thinned by up to 40-50 km to the south-southwest of the island of Hawaii. We interpret these observations as localized effects of the Hawaiian plume conduit in the asthenosphere and mantle transition zone with excess temperature of ~300°C. Large variations in the transition-zone thickness suggest a lower-mantle origin of the Hawaiian plume similar to the Iceland plume, but our results indicate a 100°C higher temperature for the Hawaiian plume. 2000 English 00280836 10.1038/35016054 Nature 405 938-941 GeoForschungsZentrum Potsdam, Telegrafenberg, 14473 Potsdam, Germany; Freie Universität, FR Geophysik, Malteserstr. 74-100, 12249 Berlin, Germany; Bullard Laboratories, Department of Earth Sciences, University of Cambridge, Cambridge CB3 0EZ, United Kingdom; Universität Potsdam, Institut für Geowissenschaften, Postfach 601553, 14415 Potsdam, Germany 6789 crustal structure; hot spot; mantle plume; seismic velocity, air temperature; article; atmosphere; geography; plume; priority journal; sea; shear rate; United States; volcano, Pacific Ocean https://www.scopus.com/inward/record.uri?eid=2-s2.0-0034702189&doi=10.1038%2f35016054&partnerID=40&md5=ca20b23fc1d932fdee5853ea4bfc0cef cited By 172 X. Li R. Kind K. Priestloy S.V. Sobolev F. Tilmann X. Yuar M. Weber article Holcomb2000547 The submarine Hilo Ridge has been interpreted as a part of Mauna Kea volcano, but is crossed at ~1100 m depth by a submerged shoreline terrace composed of basalts that are isotopically distinct from those of Mauna Kea and similar to those of Kohala volcano. This terrace evidently is a product of Kohala instead of Mauna Kea. Almost all of Hilo Ridge below the terrace therefore must predate the principal growth of Mauna Kea, which has superficially isolated the ridge from its Kohala source by overlapping its proximal segment. The Mauna Kea section penetrated by the Hawaii Scientific Drilling Project is predicted to be thinner than expected previously, owing to the overlap. Similar overlaps are suspected among other volcanoes and may cause significant changes in the understanding of Hawaiian volcanism. Article 2000 English 19432682 10.1130/0091-7613(2000)28<547:OVTOOH>2.0.CO;2 Geology 28 Geological Society of America 547 – 550 6 Hawaii [(ISL) Hawaiian Islands]; Hawaii [United States]; Hawaiian Islands; Hilo; Kohala; Mauna Kea; United States; Isotopes; Hilo Ridge; Isotope ratios; Kohala; Mauna Kea; Scientific drilling; isotopic ratio; shoreline; submarine; terrace; volcanism; volcano; Volcanoes https://www.scopus.com/inward/record.uri?eid=2-s2.0-0034432407&doi=10.1130%2f0091-7613%282000%2928%3c547%3aOVTOOH%3e2.0.CO%3b2&partnerID=40&md5=a561bc902e13bff6ac2c279c99c9711f Cited by: 29 Robin T. Holcomb Bruce K. Nelson Peter W. Reiners Nuni-Lyn Sawyer article Sobolev2000986 The hypothesis that mantle plumes contain recycled oceanic crust is now widely accepted. Some specific source components of the Hawaiian plume have been inferred to represent recycled oceanic basalts, pelagic sediments or oceanic gabbros. Bulk lava compositions, however, retain the specific trace- element fingerprint of the original crustal component in only a highly attenuated form. Here we report the discovery of exotic, strontium-enriched melt inclusions in Mauna Loa olivines. Their complete trace-element patterns strongly resemble those of layered gabbros found in ophiolites, which are characterized by cumulus plagioclase with very high strontium abundances. The major-element compositions of these melts indicate that their composition cannot be the result of the assimilation of present-day oceanic crust through which the melts have travelled. Instead, the gabbro has been transformed into a (high-pressure) eclogite by subduction and recycling, and this eclogite has then been incorporated into the Hawaiian mantle plume. The trace-element signature of the original plagioclase is present only as a 'ghost' signature, which permits specific identification of the recycled rock type. The 'ghost plagioclase' trace-element signature demonstrates that the former gabbro can retain much of its original chemical identity through the convective cycle without completely mixing with other portions of the former oceanic crust. 2000 English 00280836 10.1038/35010098 Nature 404 986-990 Max-Planck-Institut für Chemie, Postfach 3060, 55020 Mainz, Germany; Vernadsky Institute of Geochemistry, Russian Academy of Sciences, Kosygin Street 19, 117975 Moscow, Russian Federation; Department of Petrology, Vrije Universiteit, De Boelelaan 1085, 1081 HV, Amsterdam, Netherlands 6781 basalt; mantle plume; melt inclusion; oceanic crust; petrogenesis; petrology; recycling; strontium, article; geography; geology; natural science; oceanic regions; priority journal; United States; volcano, United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-0034720222&doi=10.1038%2f35010098&partnerID=40&md5=05e67efe2c21265184468079798f780c cited By 300 A.V. Sobolev A.W. Hofmann I.K. Nikogosian article Abouchami2000187 We report Pb isotopic compositions for 35 samples of the volcanoes Mauna Loa and Mauna Kea from the Hawaiian Scientific Drilling Project (HSDP-1) core at Hilo. These data were obtained with an external precision of ~ 100 ppm (2σ(ext.)) on the ratios 206Pb/204Pb, 207Pb/204Pb and 208Pb/204Pb by using a Pb triple spike to correct for instrumental mass fractionation. The Pb isotopic compositions in the lower section (1200 to 280 m) of the core sample 200 to 400 ka-old Mauna Kea lavas, and display two well-defined linear arrays in 207Pb/204Pb-206Pb/204Pb and 208Pb/204Pb-206Pb/204Pb isotope spaces. There is a suggestion that Mauna Loa (0 to 280 m depth) also displays such linear array(s). However, analysis of the Mauna Loa samples is complicated by residual contamination and/or sample heterogeneity. While these latter data exhibit a satisfactory array in 208Pb/204Pb vs. 206Pb/204Pb, there still remains scatter in 207Pb/204Pb-206Pb/204Pb space, making it difficult to assess the true Pb isotope systematics of Mauna Loa. The presence of two linear Pb isotopic arrays in Mauna Kea can be interpreted as either reflecting two parallel isochrons or in terms of binary mixing. If interpreted as isochrons, the 207Pb/204Pb-206Pb/204Pb systematics correspond to an age of ~ 1.9 Ga. Comparison of measured Th/U ratios in the lavas and those inferred from Pb isotope systematics strongly suggest that the Pb isotopic arrays reflect binary mixing, and this bears directly on the question of how many distinct components are present in the Hawaiian plume. Most of the new Mauna Kea data lie well outside the mixing-component triangle defined in the literature by the 'Kea', 'Loihi', and 'Koolau' components. On the basis of the relationships between Pb isotope ratios in 3D and a principal component analysis of the Mauna Kea Pb isotope dataset, we show here that a three-component mixing model can in principle explain both mixing lines. However, such an explanation requires a highly specific set of mixing conditions in order to produce parallel arrays in Pb isotope space (2D and 3D). Therefore, our preferred interpretation is that the two arrays reflect binary mixing, with four discrete source components involved in the generation of the Kea lavas. Comparison of the Pb isotope characteristics of these lavas with those of East Pacific Rise (EPR) MORB glasses further suggests that EPR-type Pacific lithosphere does not contribute to the source of Kea lavas. The position of samples along the mixing lines does not correlate with stratigraphic height in the core, and therefore the age of the lavas. Rather, it appears as though the relative proportions of the endmembers are controlled by the spatial configuration of these endmembers, and by melting and transport processes in the source itself. The stratigraphic fluctuations of Pb and Sr isotopes contrast with the monotonic decrease of ε(Nd) and ε(Hf) values as a function of age. This may in part be explained by differences in analytical precision of isotope measurements relative to the total range of values observed. This analytical resolution is far higher for Pb than for the other radiogenic isotopes. Alternatively, the observed fluctuation may be caused by the mobility of lead (as well as Rb and/or Sr) during the ancient differentiation process that created the differences in parent-daughter ratios. (C) 2000 Elsevier Science B.V. All rights reserved. Conference paper 2000 English 00092541 10.1016/S0009-2541(00)00328-4 Chemical Geology 169 187 – 209 1-2 United States; geochemistry; hot spot; lava; lead isotope https://www.scopus.com/inward/record.uri?eid=2-s2.0-0033812173&doi=10.1016%2fS0009-2541%2800%2900328-4&partnerID=40&md5=1e382a010fc6d87bd709e1524d680629 Cited by: 138 W. Abouchami S.J.G. Galer A.W. Hofmann article Laj199915317 Four hundred twenty five new paleointensity (Thellier-Thellier) determinations (out of 545 analyzed samples) have been obtained from core HSDP, which penetrates about 1000 meters (208 flows) of the Mauna Loa and Mauna Kea volcanic series encompassing the last 420 kyr. Rock magnetic investigations identify pseudo-single-domain magnetite as the main magnetic mineral. Inclinations are shallower than expected from a geocentric dipole field but are consistent with data from other geographical regions at the same latitude. The inclination record reveals three episodes of negative inclination whose interpolated age correlates well with that of known geomagnetic events. The paleointensity record from the Mauna Loa sequence is not very detailed and does not allow precise comparison with other data in the 0-50 kyr interval. The record from the Mauna Kea sequence, on the contrary, is very detailed and documents relatively short-lived episodes of low and high field strength from 15 to 60 μT. The average virtual dipole moment (8.7 ± 3.0 1022 A.m2) is not significantly different from the value reported by Kono and Tanaka [1995] for the last 2.5 Myr. A comparison with other data from Hawaii and other geographical regions is described in detail. There are no drastic changes in paleointensity with the inclination anomaly, in agreement with previous results from Hawaii but in contrast with most published results which, however, consider data from polarity transition. Spectral analysis of a particularly detailed portion of the record, between 420 and 326 kyr, documents significant periodicities at 36, 8, 5, and 4 ka in the inclination record but not in the intensity record, suggesting that changes in time of the inclination are to a certain extent independent from those of the intensity. Copyright 1999 by the American Geophysical Union. 1999 English 21699313 10.1029/1999jb900113 Journal of Geophysical Research: Solid Earth 104 Blackwell Publishing Ltd 15317-15338 Lab. Sci. Climat de l'Environnement, CEA-CNRS, Gif-sur-Yvette, France; Lab. Sci. Climat de l'Environnement, CEA-CNRS, 91198 Gif-sur-Yvette Cedex, France B7 magnetic intensity; paleomagnetism; Quaternary, Hawaii; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-0032698529&doi=10.1029%2f1999jb900113&partnerID=40&md5=60f205c3654e5198a1c9ddf4c7976c5c cited By 38 C. Laj C. Kissel article Lassiter1998483 Isotopic heterogeneity in Hawaiian shield lavas reflects the presence of two distinct recycled components in the Hawaiian plume, both from the same packet of recycled oceanic lithosphere. Radiogenic Os-isotopes and anomalously heavy oxygen-isotopes in Koolau lavas reflect melt generation from recycled oceanic crust plus pelagic sediment. In contrast, Kea lavas have unradiogenic Os-isotopes but anomalously light oxygen-isotopes. Oxygen-osmium-lead isotope correlations preclude generation of the Kea isotopic signature from asthenospheric upper mantle or the in situ lithospheric mantle or crust. Instead, melting of recycled, hydrothermally altered ultramafic lower crust or lithospheric mantle in the Hawaiian plume can produce Kea-type lavas. The preservation of both upper- and lower-crustal oxygen isotope signatures in plume-derived Hawaiian lavas indicates that chemical heterogeneities with length scales of only a few kilometers can be preserved in the convecting mantle for long periods of time, probably on the order of 1 Ga or more. 1998 English 0012821X 10.1016/S0012-821X(98)00240-4 Earth and Planetary Science Letters 164 483-496 Department of Terrestrial Magnetism, Carnegie Institution of Washington, Washington, DC 20015, United States 3-4 hot spot; isotopic composition; oceanic crust; osmium, Pacific Ocean https://www.scopus.com/inward/record.uri?eid=2-s2.0-0032583369&doi=10.1016%2fS0012-821X%2898%2900240-4&partnerID=40&md5=e272776d5aa88b3114baec2f46cc8d6f cited By 341 J.C. Lassiter E.H. Hauri article Paillet199611675 Temperature and formation resistivity logs obtained in borehole KP-1 of the Hawaii Scientific Drilling Project indicate that the adjacent formation is characterized by several zones of distinctly different average temperature and water salinity. A series of hydraulic analyses and water sampling programs were conducted to rule out the possibility of local hydraulic effects associated with the presence of the borehole in the generation of these apparent groundwater zones. Hydraulic tests and sampling with the borehole cased to a depth of 710 m and open below that depth indicate that the deep aquifer contains seawater at a temperature nearly identical to that of the open ocean at the same depth. Various analyses give estimates of aquifer transmissivity of about 10-3 m2/s in the vicinity of the borehole. Isolation of this deeper aquifer from the overlying groundwater zones was investigated by perforating the casing at six locations and then measuring the changes in water level in the borehole, in the salinity of the fluid column, in the temperature profile of the fluid column, and in the rate of flow in the fluid column induced by the perforations. These results positively confirm that the zones of distinctly different formation properties indicated on the temperature and resistivity logs are not caused by flow in or around casing. Flow and fluid column salinity induced by the perforations also confirm significant differences between the hydraulic heads and geochemistry of the different groundwater zones inferred from the well logs. 1996 English 21699313 Journal of Geophysical Research: Solid Earth 101 American Geophysical Union 11675-11682 U.S. Geological Survey, Denver, CO, United States; Hawaii Institute of Geophysics, University of Hawaii, Honolulu, HI, United States; U.S. Geological Survey, MS 403, Box 25046 Federal Center, Denver, CO 80225, United States; Hawaii Institute of Geophysics, University of Hawaii at Manoa, 2525 Correa Road, Honolulu, HI 96822, United States 5 aquifer; borehole logging; groundwater; hydrogeology; salinity; temperature, Hawaii; USA https://www.scopus.com/inward/record.uri?eid=2-s2.0-3643129607&partnerID=40&md5=c3335912c340a6c15ac2a55e8bfbdbf3 cited By 7 F.L. Paillet D.M. Thomas article Lipman199611631 Accumulation rates for lava flows erupted from Mauna Loa, as sampled in the uppermost 280 m of the Hilo drill hole, vary widely for short time intervals (several thousand years), but overall are broadly similar to those documented elsewhere on this volcano since 100 ka. Thickness variations and accumulation rates for Mauna Loa lavas at the Hilo drill site have been strongly affected by local paleotopography, including funneling and ponding between Mauna Kea and Kilauea. In addition, gentle submerged slopes of Mauna Kea in Hilo Bay have permitted large shoreline displacements by Mauna Loa flows. Ages of eruptive intervals have been determined from published isotopic data and from eustatic sea level curves modified to include the isostatic subsidence of the island of Hawaii at 2.2-2.6 mm/yr. Prior to 10 ka, rates of Mauna Loa lava accumulation at the drill site varied from 0.6 to 4.3 mm/yr for dateable intervals, with an overall rate of 1.8 mm/yr. Major eruptive pulses at about 1.3 and 10 ka, each probably representing a single long-lived eruption based on lack of weathering between flow units, increase the overall accumulation rate to 2.4 mm/yr. The higher rate since 10 ka reflects construction of thick near-shoreline lava deltas as postglacial sea levels rose rapidly. Large lava deltas form only along coastal segments where initially subaerial slopes have been submerged by the combined effects of eustatic sea level rise, isostatic subsidence, or spreading of volcano flanks. Overall accumulation of 239 m of lava at the drill site since 100-120 ka closely balances submergence of the Hilo area, suggesting that processes of coastal lava deposition have been modulated by rise in sea level. The Hilo accumulation rate is slightly higher than average rates of 1-2 mm/yr determined elsewhere along the Mauna Loa coast, based on rates of shoreline coverage and dated sea cliff and fault scarp exposures. Low rates of coastal lava accumulation since 100 ka, near or below the rate of island-wide isostatic subsidence, indicate that Mauna Loa is no longer growing vigorously or even maintaining its size above sea level. 1996 English 21699313 10.1029/95jb03214 Journal of Geophysical Research: Solid Earth 101 American Geophysical Union 11631-11641 U.S. Geological Survey, Menlo Park, CA, United States; U.S. Geological Survey, MS 910, 345 Middlefield Road, Menlo Park, CA 94025, United States 5 accumulation rate; coastal environment; lava delta; temporal variation; volcanic eruption, USA, Hawaii, Hawaii https://www.scopus.com/inward/record.uri?eid=2-s2.0-0029769194&doi=10.1029%2f95jb03214&partnerID=40&md5=8f5f14574e15454d3c85516e32a8f1ed cited By 33 P.W. Lipman J.G. Moore article Stolper199611593 1996 English 21699313 Journal of Geophysical Research: Solid Earth 101 American Geophysical Union 11593-11598 Div. of Geol. and Planetary Sciences, California Institute of Technology, Pasadena; Center for Isotope Geochemistry, Department of Geology and Geophysics, University of California, Berkeley; Hawaii Inst. Geophys. Planetology, Sch. Ocean Earth Sci. and Technol., University of Hawaii, Honolulu; Center for Isotope Geochemistry, Department of Geology and Geophysics, University of California, Berkeley, CA 94720-4767, United States; Div. of Geol. and Planetary Sciences, California Institute of Technology, Pasadena, CA 91125, United States; Hawaii Inst. Geophys. Planetology, Sch. Ocean Earth Sci. and Technol., Univresity of Hawaii, Honolulu, HI 96822, United States B5 https://www.scopus.com/inward/record.uri?eid=2-s2.0-14244259538&partnerID=40&md5=833430d18e66a9d94a340ffd32614410 cited By 44 E.M. Stolper D.J. DePaolo D.M. Thomas article Thomas199611683 A series of downhole and surface water samples were taken from the 1-km-deep KP-1 borehole located on the eastern flank of the island of Hawaii. Early samples from depths of more than 700 m showed salinities nearly equivalent to seawater but having anomalous cation concentrations that are attributed to ion exchange between formation fluids and residual drilling mud clays. Later deep samples found only minor variations from seawater cation chemistry that are consistent with low-temperature weathering of basalts; δ18O values are equivalent to seawater values and are consistent with this interpretation. Carbon 14 activities of dissolved inorganic carbonate indicate a water age ranging from 5890 to 7170 years B.P. and fluid transport rates of 1.8 to 2.2 m/yr. Fluid samples from perforations at 310 m in the borehole demonstrate that a freshwater aquifer is present at the Mauna Kea/Mauna Loa interface; borehole resistivity logs indicate that it is ∼200 m thick. Although it has not yet been possible to obtain samples of the freshwater zone without contamination from the deep saline fluids, the chloride concentrations of the low-salinity zone are estimated using a mixing enthalpy calculation to be less than 100 mg/L. Light stable isotope data indicate that the fresh water at 320 m is derived from recharge entering the island at an average elevation of 2000 m. Inferred 14C activities of the dissolved bicarbonate in the freshwater zone indicate an average calibrated age of 2200 years B.P. and an average fluid velocity of at least 14 m/yr. A regional water flow model is proposed that suggests that the fresh water found at the 320-m depth is derived from rainfall recharge from the middle elevations of Mauna Kea volcano. This rainfall is channeled beneath the Mauna Loa lavas by the thick soil layer separating the two volcanoes. A second shallow fresh-to-brackish water zone, derived from Mauna Loa recharge, is also inferred to exist below the carbonate formation that underlies the shallow basal lens. The results of our preliminary study of the groundwater system below the KP-1 drill site demonstrate that intervolcano and interflow aquicludes can have a substantial impact on water circulation and discharge from young island volcanoes. 1996 English 21699313 10.1029/95jb03845 Journal of Geophysical Research: Solid Earth 101 American Geophysical Union 11683-11694 Hawaii Inst. Geophys. Planetology, Sch. Ocean Earth Sci. and Technol., University of Hawaii at Manoa, Honolulu, HI, United States; U.S. Geological Survey, Denver, CO, United States; Lawrence Berkeley Laboratory, Berkeley, CA, United States; Lawrence Berkeley Laboratory, Bldg. 70A, MS 33663, 1 Cyclotron Rd., Berkeley, CA 94720, United States; U.S. Geological Survey, MS 403, Box 25046 Federal Center, Denver, CO 80225, United States; Hawaii Inst. Geophys. Planetology, SOEST, University of Hawaii, 2525 Correa Road, Honolulu, HI 96822-2219, United States 5 fluid flow; freshwater; geochemistry; groundwater; hydrogeology; salinity, USA, Hawaii, Hawaii https://www.scopus.com/inward/record.uri?eid=2-s2.0-0029751779&doi=10.1029%2f95jb03845&partnerID=40&md5=fe8f677d942497ac0aabc8aafefe4016 cited By 29 D.M. Thomas F.L. Paillet M.E. Conrad article Moore199611599 A 25.8-m-thick sedimentary section containing coral fragments occurs directly below a surface lava flow (the ∼1340 year old Panaewa lava flow) at the Hilo drill hole. Ten coral samples from this section dated by accelerator mass spectrometry (AMS) radiocarbon and five by thermal infrared multispectral scanner (TIMS) 230Th/U methods show good agreement. The calcareous unit is 9790 years old at the bottom and 1690 years old at the top and was deposited in a shallow lagoon behind an actively growing reef. This sedimentary unit is underlain by a 34-m-thick lava flow which in turn overlies a thin volcaniclastic silt with coral fragments that yield a single 14C date of 10,340 years. The age-depth relations of the dated samples can be compared with proposed eustatic sea level curves after allowance for island subsidence is taken. Island subsidence averages 2.2 mm/yr for the last 47 years based on measurements from a tide gage near the drill hole or 2.5-2.6 mm/yr for the last 500,000 years based on the ages and depths of a series of drowned coral reefs offshore from west Hawaii. The age-depth measurements of coral fragments are more consistent with eustatic sea levels as determined by coral dating at Barbados and Albrolhos Islands than those based on oxygen isotopic data from deep sea cores. The Panaewa lava flow entered a lagoon underlain by coral debris and covered the drill site with 30.9 m of lava of which 11 m was above sea level. This surface has now subsided to 4.2 m above sea level, but it demonstrates how a modern lava flow entering Hilo Bay would not only change the coastline but could extensively modify the offshore shelf. 1996 English 21699313 10.1029/95jb03215 Journal of Geophysical Research: Solid Earth 101 American Geophysical Union 11599-11605 U.S. Geological Survey, Menlo Park, CA, United States; Department of Geology and Geophysics, University of California, Berkeley, CA, United States; U.S. Geological Survey, Denver, CO, United States; U.S. Geological Survey, Hawaiian Volcano Observatory, Hawaii National Park, HI, United States; U.S. Geological Survey, Hawaiian Volcano Observatory, Hawaii National Park, HI 96718, United States; Department of Geology and Geophysics, University of California, Berkeley, CA 94720, United States; U.S. Geological Survey, Federal Center, Denver, CO 80225, United States; U.S. Geological Survey, MS 910, 345 Middlefield Road, Menlo Park, CA 94025, United States 5 age determination; coral; lava flow; radiocarbon dating; subsidence; thorium/uranium dating, USA, Hawaii, Hawaii https://www.scopus.com/inward/record.uri?eid=2-s2.0-0029751838&doi=10.1029%2f95jb03215&partnerID=40&md5=f065689c6758da3994586cede3b2150b cited By 43 J.G. Moore B.L. Ingram K.R. Ludwig D.A. Clague article DePaolo1996 Petrological, geochemical, geomagnetic, and volcanological characterization of the recovered core from a 1056-m-deep well into the flank of the Mauna Kea volcano in Hilo, Hawaii, and downhole logging and fluid sampling have provided a unique view of the evolution and internal structure of a major oceanic volcano unavailable from surface exposures. Core recovery was ∼90%, yielding a time series of fresh, subaerial lavas extending back to ∼400 ka. Results of this 1993 project provide a basis for a more ambitious project to core drill a well 4.5 km deep in a nearby location with the goal of recovering an extended, high-density stratigraphic sequence of lavas. 1996 English 10525173 GSA Today 6 Geological Society of America x1-8 UC Berkeley; Caltech; U. Hawaii; JPL; USGS - HVO; MIT; Mainz, Germany; Lawrence Berkeley Lab; WHOI; USGS; BGC-Berkeley; U. Mass. 8 geochemistry; geomagnetic field; hotspot; petrology; volcanism; volcano, USA, Hawaii, Hawaii, Mauna Kea https://www.scopus.com/inward/record.uri?eid=2-s2.0-0030427741&partnerID=40&md5=6fd129cbc07efd46c462412571f44969 cited By 14 D. DePaolo E. Stolper D. Thomas F. Albarède O. Chadwick D. Clague M. Feigenson F. Frey M. Garcia A. Hofmann B.L. Ingram B.M. Kennedy J. Kirschvink M. Kurz C. Laj J. Lockwood K. Ludwig T. McEvilly R. Moberly G. Moore J. Moore R. Morin F. Paillet P. Renne M. Rhodes M. Tatsumoto H. Taylor G. Walker R. Wilkins article Rhodes199611729 Geochemical discriminants are used to place the boundary between Mauna Loa flows and underlying Mauna Kea flows at a depth of about 280 m. At a given MgO content the Mauna Kea flows are lower in SiO2 and total iron and higher in total alkali, TiO2, and incompatible elements than the Mauna Loa lavas. The uppermost Mauna Kea lavas (280 to 340 m) contain alkali basalts interlayered with tholeiites and correlate with the postshield Hamakua Volcanics. In addition to total alkalis, the alkali basalts have higher TiO2, P2O5, Sr, Ba, Ce, La, Zr, Nb, Y, and V relative to the tholeiites and lower Zr/Nb and Sr/Nb ratios. Some of the alkali basalts are extensively differentiated. Below 340 m all the flows are tholeiitic, with compositions broadly similar to the few "fresh" subaerial shield-building Mauna Kea tholeiites studied to date. High-MgO lavas are unusually abundant, although there is a wide range (7-28%) in MgO content reflecting olivine control. FeO/MgO relationships are used to infer parental picritic magmas with about 15 wt % MgO. Lavas with more MgO than this have accumulated olivine. The Mauna Loa lavas have compositional trends that are controlled by olivine crystallization and accumulation. They compare closely with trends for historical (1843-1984) flows, tending toward the depleted end of the spectrum. They are, though, much more MgO-rich (9-30%) than is typical for most historical and young (&lt;30 ka) prehistoric lavas. The unusual abundance of high-MgO and picritic lavas is attributed to the likelihood that only large-volume, hot, mobile flows will reach Hilo Bay from the northeast rift zone. FeO/MgO relationships are used to infer parental picritic magmas with about 17 wt % MgO. Again, lavas with more MgO than this have accumulated olivine. Systematic changes in incompatible element ratios are used to argue that the magma supply rate has diminished over time. On the other hand, the relatively constant Zr/Nb and Sr/Nb ratios that compare closely with historical and young (&lt;30 kyr) prehistoric flows are used to argue that the source components for these lavas in the Hawaiian plume have remained relatively uniform over the last 100 kyr. 1996 English 21699313 10.1029/95jb03704 Journal of Geophysical Research: Solid Earth 101 American Geophysical Union 11729-11746 Department of Geosciences, University of Massachusetts, Amherst, MA, United States; Department of Geosciences, University of Massachusetts, Morrill Science Center, Amherst, MA 01003, United States 5 basalt; geochemistry; lava flow; petrogenesis; stratigraphy, USA, Hawaii, Hawaii https://www.scopus.com/inward/record.uri?eid=2-s2.0-0029730270&doi=10.1029%2f95jb03704&partnerID=40&md5=aed7f67eed4cf1834097e60129222eb3 cited By 141 J.M. Rhodes article Yang199611747 The lower 776 m of core recovered during the initial phase of the Hawaii Scientific Drilling Project (HSDP) contains lavas erupted from Mauna Kea volcano. Tholeiitic and alkalic basalts, including an Fe-Ti rich flow, are intercalated in the upper 58 m of Mauna Kea lavas. Similar basaltic sections are subaerially exposed on the lower east flank of Mauna Kea. The Fe-Ti rich lavas reflect large amounts of clinopyroxene, plagioclase, and olivine fractionation within the crust and upper mantle, but the range from tholeiitic to alkalic compositions reflects variable extents of melting of a garnet-bearing source. Based on abundances of incompatible elements, the extent of melting for a basanitoid was a factor of 2 less than that for nearly coeval tholeiitic lavas. All flow units in the lower 718 m of the HSDP core are tholeiitic lavas. Their variability in major element compositions reflect variable accumulation of olivine. Incompatible element abundance ratios in these lavas reflect a complex temporal variation in extent of melting. Within the tholeiitic part of the core, lavas from 800 m to 950 m formed by the largest extent of melting, whereas tholeiitic lavas from the bottom of the core and from just below the tholeiitic to alkalic transition formed by lower degrees of melting. Inferred melt compositions at 16% MgO show that the ∼200 to 400 ka Mauna Kea lavas from the HSDP core and the &lt;250 ka subaerial exposures define an inverse correlation between SiO2 and FeO contents. Based on experimental studies, this correlation is caused by differing pressures of melt segregation. Furthermore, abundances of Nb and SiO2 are also inversely correlated in these calculated melts. In general, the younger lavas are relatively enriched in FeO and incompatible elements but are depleted in SiO2. These trends are interpreted to reflect an overall trend of increasing pressure of melt segregation and decreasing extent of melting with decreasing eruption age. There are, however, geochemical variations which indicate short-term reversals in this long-term trend. Previously, the geochemical trends accompanying the transition from tholeiitic to alkalic volcanism at Hawaiian volcanoes have been interpreted as reflecting the effects of increasing distance from the plume axis. The long-term geochemical trends of tholeiitic lavas in the HSDP core also reflect migration of Mauna Kea away from the Hawaiian plume. 1996 English 21699313 10.1029/95jb03465 Journal of Geophysical Research: Solid Earth 101 American Geophysical Union 11747-11767 Dept. Earth, Atmosph. Planet. Sci., Massachusetts Inst. of Technology, Cambridge, MA, United States; Department of Geology and Geography, University of Massachusetts, Amherst, MA, United States; Department of Geology and Geophysics, University of Hawaii at Manoa, Honolulu, HI, United States; Dept. Earth, Atmosph. Planet. Sci., Massachusetts Inst. of Technology, Cambridge, MA 02139-4307, United States; Department of Geology and Geophysics, SOEST, University of Hawaii at Manoa, 2525 Correa Road, Honolulu, HI 96822, United States; Department of Geology and Geography, University of Massachusetts, Morrill Science Center, Amherst, MA 01003-5820, United States 5 basalt; geochemistry; lava flow; petrogenesis; petrology; temporal evolution; volcano, USA, Hawaii, Hawaii, Mauna Kea https://www.scopus.com/inward/record.uri?eid=2-s2.0-0029749664&doi=10.1029%2f95jb03465&partnerID=40&md5=0c856606292a3cb7d5d9d4d719a64eca cited By 50 H.-J. Yang F.A. Frey J.M. Rhodes M.O. Garcia article Morin199611695 As part of the Hawaii Scientific Drilling Project, Kahi Puka Well 1 penetrated about 275 m of Mauna Loa basalts overlying a sequence of Mauna Kea flow units as it was drilled and cored to a total depth of 1053 m below land surface. A borehole televiewer (BHTV) was run in most of the well in successive stages prior to casing in order to obtain magnetically oriented acoustic images of the borehole wall. A total of 283 individual fractures were identified from this log and characterized in terms of strike and dip. These data are divided into three vertical sections based upon age and volcanic source, and lower hemisphere stereographic plots identify two predominant, subparallel fracture subsets common to each section. Assuming that most of the steeply dipping fractures observed in the BHTV log are tensile features generated within basalt flows during deposition and cooling, this fracture information can be combined with models of the evolution of the island of Hawaii to investigate the depositional history of these Mauna Loa and Mauna Kea basalts over the past 400 kyr. The directions of high-angle fractures appear to be generally parallel to topography or to the coastline at the time of deposition, as is supported by surface mapping of modern flows. Consequently, an overall counterclockwise rotation of about 75° in the strike of these fractures from the bottom to the top of the well represents a systematic change in depositional slope direction over time. We attribute the observed rotation in the orientations of the two predominant fracture subsets over the past 400 kyr to changes in the configurations of volcanic sources during shield building and to the structural interference of adjacent volcanoes that produces shifts in topographic patterns. 1996 English 21699313 10.1029/95jb03848 Journal of Geophysical Research: Solid Earth 101 American Geophysical Union 11695-11699 U.S. Geological Survey, Denver, CO, United States; U.S. Geological Survey, MS 403, Denver Federal Center, P.O. Box 25046, Denver, CO 80225, United States 5 borehole logging; borehole televiewer; fracture geometry; tensile fracture; volcano growth, USA, Hawaii, Hawaii https://www.scopus.com/inward/record.uri?eid=2-s2.0-0029776993&doi=10.1029%2f95jb03848&partnerID=40&md5=b397f583aa27f36d3bc72a9471710ca3 cited By 3 R.H. Morin F.L. Paillet article Sharp199611607 Mauna Kea lava flows cored in the HilIo hole range in age from &lt;200 ka to about 400 ka based on 40Ar/39Ar incremental heating and K-Ar analyses of 16 groundmass samples and one coexisting plagioclase. The lavas, all subaerially deposited, include a lower section consisting only of tholeiitic basalts and an upper section of interbedded alkalic, transitional tholeiitic, and tholeiitic basalts. The lower section has yielded predominantly complex, discordant 40Ar/39Ar age spectra that result from mobility of 40Ar and perhaps K, the presence of excess 40Ar, and redistribution of 39Ar by recoil. Comparison of K-Ar ages with 40Ar/39Ar integrated ages indicates that some of these samples have also lost 39Ar. Nevertheless, two plateau ages of 391 ± 40 and 400 ± 26 ka from deep in the hole, combined with data from the upper section, show that the tholeiitic section accumulated at an average rate of about 7 to 8 m/kyr and has an mean recurrence interval of 0.5 kyr/flow unit. Samples from the upper section yield relatively precise 40Ar/39Ar plateau and isotope correlation ages of 326 ± 23, 241 ± 5, 232 ± 4, and 199 ± 9 ka for depths of -415.7 m to -299.2 m. Within their uncertainty, these ages define a linear relationship with depth, with an average accumulation rate of 0.9 m/kyr and an average recurrence interval of 4.8 kyr/flow unit. The top of the Mauna Kea sequence at -280 m must be older than the plateau age of 132 ± 32 ka, obtained for the basal Mauna Loa flow in the corehole. The upward decrease in lava accumulation rate is a consequence of the decreasing magma supply available to Mauna Kea as it rode the Pacific plate away from its magma source, the Hawaiian mantle plume. The age-depth relation in the core hole may be used to test and refine models that relate the growth of Mauna Kea to the thermal and compositional structure of the mantle plume. 1996 English 21699313 10.1029/95jb03702 Journal of Geophysical Research: Solid Earth 101 American Geophysical Union 11607-11616 Berkeley Geochronology Center, Berkeley, CA, United States; U.S. Geological Survey, Menlo Park, CA, United States; U.S. Geological Survey, MS 977, 345 Middlefield Road, Menlo Park, CA 94025, United States; Berkeley Geochronology Center, 2455 Ridge Road, Berkeley, CA 94720, United States 5 accumulation rate; alkali basalt; argon-40/argon-39 dating; lava flow; petrology; potassium/argon dating; recurrence interval; tholeiite, USA, Hawaii, Hawaii https://www.scopus.com/inward/record.uri?eid=2-s2.0-0029729311&doi=10.1029%2f95jb03702&partnerID=40&md5=fc04401fcd1ed6f0db4055c75ba04a76 cited By 88 W.D. Sharp B.D. Turrin P.R. Renne M.A. Lanphere