This file was created by the TYPO3 extension publications --- Timezone: CEST Creation date: 2026-06-13 Creation time: 03:45:42 --- Number of references 53 article Shervais2024 Article 2024 10.1016/j.geothermics.2023.102865 Geothermics 117 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85177873679&doi=10.1016%2fj.geothermics.2023.102865&partnerID=40&md5=a2d359cf012aadc5a477ef1d831e88da Cited by: 8; All Open Access, Gold Open Access, Green Open Access John W. Shervais Jacob DeAngelo Jonathan M. Glen Dennis L. Nielson Sabodh Garg Patrick Dobson Erika Gasperikova Eric Sonnenthal Lee M. Liberty Dennis L. Newell Drew Siler James P. Evans article DeAngelo2024 Article 2024 10.1016/j.geothermics.2023.102882 Geothermics 117 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85178654658&doi=10.1016%2fj.geothermics.2023.102882&partnerID=40&md5=03ed63a75ae826765523ef55c0c2a1e1 Cited by: 5; All Open Access, Green Open Access, Hybrid Gold Open Access Jacob DeAngelo John W. Shervais Jonathan M. Glen Dennis Nielson Sabodh Garg Patrick F. Dobson Erika Gasperikova Eric Sonnenthal Lee M. Liberty Drew L. Siler James P. Evans article Shervais20244252 Article 2024 10.1130/B37413.1 Bulletin of the Geological Society of America 136 4252 – 4262 9-10 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85203428546&doi=10.1130%2fB37413.1&partnerID=40&md5=7b5eb80263bc760efed910071a7bcaec Cited by: 0 John W. Shervais Katherine E. Potter article Wetzel2022885 The western Snake River Plain (WSRP) in southwest Idaho has been characterized as an intracontinental rift basin but differs markedly in topography and style from other Cordilleran extensional structures and structurally from the down-warped lava plain of the eastern Snake River Plain. To investigate mechanisms driving extension and topographic evolution, we sampled granitoid bedrock from Cretaceous and Eocene-aged plutons from the mountainous flanks of the WSRP to detail their exhumation history with apatite (U-Th)/He (AHe) thermochronometry. AHe cooling dates from seventeen samples range from 7.9 ± 1.4 Ma to 55 ± 10 Ma. Most cooling dates from Cretaceous plutons adjacent to the WSRP are Eocene, while Eocene intrusions from within the Middle Fork Boise River canyon ~35 km NE of the WSRP yield Miocene cooling dates. The AHe dates provide evidence of exhumation of the Idaho batholith during the Eocene, supporting a high relief landscape at that time, followed by decreasing relief. The Miocene AHe dates show rapid cooling along the Middle Fork Boise River that we take to indicate focused river incision due to base level fall in the WSRP. Eocene AHe dates limit magnitudes of exhumation and extension on the flanks of the WSRP during Miocene rift formation. This suggests extension was accommodated by magmatic intrusions and intrabasin faults rather than basin-bounding faults. We favor a model where WSRP extension was related to Columbia River Flood Basalt eruption and enhanced by later eruption of the Bruneau-Jarbidge and Twin Falls volcanic fields, explaining the apparent difference with other Cordilleran extensional structures. © 2022. The Authors. All Rights Reserved. 2022 English 1553040X 10.1130/GES02453.1 Geosphere 18 Geological Society of America 885-909 Department of Geography and Geological Sciences, University of Idaho, 875 Perimeter Drive, MS3022, Moscow, ID 83844, United States 2 Apatite; Basalt; Cooling; Tectonics; Topography, Idaho Batholith; Magmatic intrusions; Magmatic process; Miocene; Plutons; Rapid cooling; Rift basin; Snake river plains; Thermochronometry; U-Th/He thermochronology, Rivers, apatite; bedrock; exhumation; granitoid; magmatism; pluton; relief; rift zone; thermochronology; uranium series dating, Idaho; Snake River Plain; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-85129728710&doi=10.1130%2fGES02453.1&partnerID=40&md5=bb65e9f963aa59b4fce762e52de58c39 cited By 0 K.F. Wetzel J.R. Stanley article Allstädt2021177 Marked by the expansion of ice sheets in the high latitudes, the intensification of Northern Hemisphere glaciation across the Plio/Pleistocene transition at ~ 2.7 Ma represents a critical interval of late Neogene climate evolution. To date, the characteristics of climate change in North America during that time and its imprint on vegetation has remained poorly constrained because of the lack of continuous, highly resolved terrestrial records. We here assess the vegetation dynamics in northwestern North America during the late Pliocene and early Pleistocene (c. 2.8–2.4 Ma) based on a pollen record from a lacustrine sequence from paleo-Lake Idaho, western Snake River Plain (USA) that has been retrieved within the framework of an International Continental Drilling Program (ICDP) coring campaign. Our data indicate a sensitive response of forest ecosystems to glacial/interglacial variability paced by orbital obliquity across the study interval, and also highlight a distinct expansion of steppic elements that likely occurs during the first strong glacial of the Pleistocene, i.e. Marine Isotope Stage 100. The pollen data document a major forest biome change at ~ 2.6 Ma that is marked by the replacement of conifer-dominated forests by open mixed forests. Quantitative pollen-based climate estimates suggest that this forest reorganisation was associated with an increase in precipitation from the late Pliocene to the early Pleistocene. We attribute this shift to an enhanced moisture transport from the subarctic Pacific Ocean to North America, confirming the hypothesis that ocean-circulation changes were instrumental in the intensification of Northern Hemisphere glaciation. © 2021, The Author(s). 2021 English 18671594 10.1007/s12549-020-00460-1 Palaeobiodiversity and Palaeoenvironments 101 Springer Science and Business Media Deutschland GmbH 177-195 Institute of Earth Sciences, Heidelberg University, Im Neuenheimer Feld 234–236, Heidelberg, 69120, Germany; Department of Geosciences, University of Tübingen, Hölderlinstraße 12, Tübingen, 72074, Germany; Department of Geosciences, University of Connecticut, 354 Mansfield Road, Storrs, CT 06269, United States; Institute of Geosciences, University of Potsdam, Karl-Liebknecht-Straße 24-26, Potsdam-Golm, 14467, Germany; Institute of Geology and Mineralogy, University of Cologne, Zülpicherstr. 49a, Cologne, 50674, Germany 1 climate effect; climate variation; drilling; glaciation; ice sheet; Neogene; palynology; Pliocene-Pleistocene boundary; proxy climate record; vegetation dynamics, Idaho; North America; Pacific Ocean; Snake River Plain; United States, Coniferophyta https://www.scopus.com/inward/record.uri?eid=2-s2.0-85099108452&doi=10.1007%2fs12549-020-00460-1&partnerID=40&md5=6a1c414e97ff9df8f59b81129feccbfe cited By 4 F.J. Allstädt A. Koutsodendris E. Appel W. Rösler T. Reichgelt S. Kaboth-Bahr A.A. Prokopenko J. Pross article Allstädt2020754 Remagnetization is an important issue in palaeomagnetism. Here, we discuss an extraordinarily thick (∼74 m) dual-polarity transition zone between the Gauss and Matuyama Chrons. The studied succession is from a drill core through lacustrine sediments of palaeo-Lake Idaho (Snake River Plain, NW United States of America) that are intercalated with basalt units. We identified detrital Ti-rich titanomagnetite and magnetite in lamellar exsolutions as the main carriers of a primary remanence, likely derived from the basalts that erupted in the Snake River Plain. Stepwise thermal demagnetization revealed a single-component remanent magnetization with reversed and normal polarities above and below the transition zone, respectively. Based on rock-magnetic results, microscopic observations, and previously known events in the evolution of palaeo-Lake Idaho, the reversed-polarity component in the transition zone represents a secondary chemical remanent magnetization caused by magnetic mineral alteration or partial neo-formation of magnetite, in association with strong depletion of the primary detrital magnetic minerals that affected a wide depth range below the level where the remagnetization event occurred. This remagnetization event was most likely related to lake-level lowering and partial desiccation of palaeo-Lake Idaho. Understanding the nature and origin of the remagnetization allows to identify the polarity boundary in the unusual case of a secondary magnetization with reversed polarity produced downward in a sequence to an extraordinary large depth. Based on available age information, the observed reversal represents the Gauss/Matuyama boundary, which provides an important age constraint for palaeoclimatic interpretation of the succession. © 2020 The Author(s) 2020. Published by Oxford University Press on behalf of The Royal Astronomical Society. 2020 English 0956540X 10.1093/gji/ggaa165 Geophysical Journal International 222 Oxford University Press 754-768 Paleoenvironmental Dynamics Group, Institute of Earth Sciences, Heidelberg University, Im Neuenheimer Feld 234-236, Heidelberg, 69120, Germany; Department of Geosciences, University of Tübingen, Hölderlinstr. 12, Tübingen, 72074, Germany; Institute of Geology and Mineralogy, University of Cologne, Zülpicherstr. 49a, Cologne, 50674, Germany 2 Basalt; Core drilling; Demagnetization; Gaussian distribution; Geomagnetism; Lakes; Lithology; Magnetite; Magnetization; Minerals, Chemical remanent magnetization; Lacustrine sediments; Microscopic observations; Remanent magnetization; Single components; Snake river plains; Stepwise thermal demagnetization; United States of America, Magnetic polarity, basalt; geomagnetism; lacustrine deposit; magnetic mineral; paleomagnetism; remagnetization; remanent magnetization; titanomagnetite, Idaho; Snake River Plain; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-85086761818&doi=10.1093%2fgji%2fggaa165&partnerID=40&md5=a425f2e0c2810c2ed506487e427792aa cited By 1 F.J. Allstädt E. Appel W. Rösler A.A. Prokopenko U. Neumann T. Wenzel J. Pross article AssisFernandes2019289 This study presents 40Ar-39Ar step heating ages of four North American tektites (three bediasites and one georgiaite) and of two groundmass samples extracted at different depths from clast-rich impact melt rocks (CB-W61 and CB-W84) recovered by the USGS-ICDP Eyreville B drill-core about 9 km from the centre of the Chesapeake Bay impact structure. Radiometric age determination on both North American tektites and impact melt rocks from within Chesapeake Bay crater offers the first possibility to confirm the origin of these tektites. For this aim, argon isotopic data from 13 samples/aliquots of tektite rims, cores and bulk, and 4 samples/aliquots from two impact melt rocks were obtained over 15 to 26 step heating extractions. Age spectra of all tektite samples show plateaux comprising 62–98% of the 39Ar release over consecutive intermediate and high temperature heating steps. Few low temperature extractions indicate excess 40Ar. Inverse isochron 40Ar/36Ar intercepts of tektite samples are indistinguishable from air (295.5). However, impact melt rock spectra presented complex Ar-release affecting primarily the low temperature heating-steps. Inverse isochrones indicate excess argon from which the 40Ar/36Ar intercept was used to correct the age calculation. CB-W61 and CB-W61-2 40Ar/36Ar intercepts are 354.5 ± 2.5 and 327.2 ± 6.3, respectively, and those for CB-W84 and CB-W84-2 are 332.0 ± 7.3 and 329.6 ± 5.6, respectively. The inverse isochron weighted mean age (according to currently suggested K-decay constants revisions by Schwarz et al. (2011) and Renne et al. (2011)) for all four tektites is 34.86 ± 0.25 Ma (MSWD = 0.96, P = 0.41; n = 4) and for the two impact melt rocks is 37.16 ± 3.65 Ma (MSWD = 0.83, P = 0.36). The combined tektite and impact melt rocks isochron mean age of 34.86 ± 0.23 (0.32) Ma (MSWD = 0.87, P = 0.43) is slightly – though not significantly – higher than the plateau mean age of 34.55 ± 0.27 (0.36) Ma (MSWD = 0.66, P = 0.62). Placing this age in the Global Stratotype Section and Point (GSSP) marine section exposed at Massignano, Italy, it falls below the Eocene/Oligocene (E/O) boundary overlapping with the 10.28 m Ir-anomaly. These results agree within errors with previously reported ages of 35.20 ± 0.54 Ma, especially those derived from K-Ar and Ar-Ar total fusion analysis. An age of 34.86 ± 0.32 Ma sets the Chesapeake Bay impact event close to the youngest of the three Ir anomalies at ∼35.0 Ma in the case the impactor was Ir-rich (e.g, a chondrite, primitive achondrite, stony-iron or iron meteorite). The concordance with the E/O boundary at ∼33.9 Ma seems only marginally possible, and only if the Ir contribution from the ejecta were, potentially, due either to its small amount becoming diluted in the geologic record or the impactor being Ir poor, e.g., of differentiated achondritic composition. This study also brings to front the need to re-establish the stratigraphic and palaeo-magnetic correlations across the globe for the Ir-anomalies and the magneto-stratigraphy during the mid- to late-Eocene and early-Oligocene, and the need to re-evaluate the markers for the Eocene-Oligocene boundary. © 2019 Elsevier Ltd 2019 English 00167037 10.1016/j.gca.2019.03.004 Geochimica et Cosmochimica Acta 255 Elsevier Ltd 289-308 Museum für Naturkunde, Leibniz-Institute for Evolution and Biodiversity Research, Invalidenstraße 43, Berlin, 10115, Germany; School of Earth and Environmental Sciences, University of Manchester, Oxford Road, Manchester, M13 9PL, United Kingdom; Instituto Dom Luiz, University of Lisbon, Lisbon, 1749-016, Portugal; Klaus-Tschira-Labor für Kosmochemie, Institut für Geowissenschaften, Ruprecht-Karls-Universität Heidelberg, Im Neuenheimer Feld 234-236, Heidelberg, 69120, Germany; Saalbau Weltraum Projekt, Liebigstrasse 6, Heppenheim, 64646, Germany; Zentrum für Rieskrater und Impaktforschung (ZERIN), Nördlingen, Vordere Gerbergasse 3, Nördlingen, 86720, Germany; Florida Institute of Technology, Melbourne, FL 32901, United States argon-argon dating; Eocene-Oligocene boundary; geochronology; impact structure; magnetostratigraphy; melt; meteorite; paleomagnetism; tektite, Ascoli Piceno; Chesapeake Bay; Italy; Marche; Massignano; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-85063349910&doi=10.1016%2fj.gca.2019.03.004&partnerID=40&md5=a88b722be178770fe56331e4a1c9004b cited By 9 V. Assis Fernandes J. Hopp W.H. Schwarz J.P. Fritz M. Trieloff H. Povenmire article Lachmar2019 A geothermal exploration corehole was drilled to a total depth of 1821.5 m on the Mountain Home Air Force Base near Mountain Home, Idaho. The corehole was used to collect an unusually large amount of data, including uniaxial compressive stress (UCS) experiments on core samples, to evaluate the geothermal potential of the western Snake River Plain. In addition, unlike many exploration holes in this region, a fluid entry was encountered at 1745.3 m and flowed artesian to the surface. A maximum temperature of 149.4 °C was calculated for the entry. A temperature log run on the corehole from 3 to 1675 m is nearly linear with little variation. The average geothermal gradient is 73 °C/km, and the average heat flow between 200 and 1500 m is 102 ± 15 mW/m2. Chemical analyses of a sample from the fluid entry suggest that a significant proportion of the water is not meteoric. Five geothermometers show equilibrium temperature in the range of 133–157 °C. Furthermore, based on the unconfined UCS experiments on basalt core samples, a brittle unit was found to comprise the fractured reservoir that the geothermal water flows from, while an overlying ductile unit acts as a hydrothermal caprock. This implies that the reservoir/caprock pair may be a target for future exploration wells drilled to delineate the extent of the potential resource and the boundaries of the connected fracture network. © 2019, The Author(s). 2019 English 21959706 10.1186/s40517-019-0142-7 Geothermal Energy 7 SpringerOpen Department of Geosciences, Utah State University, Logan, UT 84322-4505, United States; Department of Earth Sciences, Southern Methodist University, P.O. Box 750395, Dallas, TX 75275, United States; DOSECC Exploration Services, LLC, 2057 Pioneer Road, Salt Lake City, UT 84104, United States; Department of Physics, University of Alberta, 4-181 CCIS, Edmonton, AB T6G 2E1, Canada; Department of Earth, Atmospheric, and Planetary Sciences, Purdue University, West Lafayette, IN 47907-2051, United States 1 Basalt; Chemical analysis; Core samples; Geothermal prospecting; Heat transfer; Infill drilling; Landforms; Thermal logging, Equilibrium temperatures; Geothermal exploration; Geothermal gradients; Geothermal potential; Geothermometers; Potential resources; Temperature log; Uniaxial compressive, Geothermal energy, basalt; compressive strength; experimental study; geothermal energy; geothermal power; geothermometry; heat flow; temperature effect; uniaxial strength, Idaho; Snake River Plain; United States, Calluna vulgaris https://www.scopus.com/inward/record.uri?eid=2-s2.0-85071910583&doi=10.1186%2fs40517-019-0142-7&partnerID=40&md5=b35ccfbd7f9245c5ebcb42d23da4af66 cited By 3 T.E. Lachmar T.G. Freeman J.A. Kessler J.F. Batir J.P. Evans D.L. Nielson J.W. Shervais X. Chen D.D. Blackwell article Potter2019736 The Snake River Plain of central Idaho represents the world's best example of a mantle hotspot track impinging upon continental crust and provides a record of bimodal volcanism extending over 12 Ma to the present. Project Hotspot recovered almost 2 km of continuous drill core from the Kimama borehole, located in central Idaho on the axial volcanic zone. The Kimama drill core represents the most complete record of mafic volcanism along the Yellowstone-Snake River Plain hotspot track. A total of 432 basalt flow units, representing 183 basalt flows, 78 basalt flow groups, and 34 super groups, along with 42 sediment interbeds are recognized using volcanic facies observations, stratigraphic relationships, borehole geophysical logs, and paleosecular variation in magnetostratigraphy. Rhyolite and other non-basaltic volcanic materials were not encountered in the drill core. Ages for six basalt lava flows were determined by 40Ar/39 using incremental heating experiments. Paleomagnetic inclination was measured on over 1200 samples collected at roughly 2-m-depth intervals, yielding mean values of paleosecular variation between ±50° to ±70° in Kimama flow groups, close to the expected 61° axial dipole average for the Kimama borehole location. Twenty-three magnetic reversals were identified and correlated to dated geomagnetic chrons and subchrons and compared with the 40Ar/39 radiometric ages. A linear fit to 40Ar/39Ar dates, geomagnetic chron and subchron boundaries, and volcanogenic zircon U-Pb ages defines a mean accumulation rate of ~320 m/m.y. and extrapolates to a bottom hole age of 6.3 Ma. Average thicknesses of lithologic units increase from 2.7 m (sediment), 4 m (flow units), 10 m (flows), 23 m (flow groups), to 53 m (super groups). On average, one lava flow inundated the Kimama borehole location every 33 k.y. Intercalated sediments, ranging from 0.06 to 24.5 m thick, make up roughly 6% of the drill core and indicate lulls in local volcanic activity that may have lasted up to 77 k.y. Neutron and gamma-ray logs supplement observations from the drill cores: neutron logs document individual flow units through the contrast between massive flow interiors and more porous flow surfaces, and gamma-ray logs document the depth and thickness of sedimentary interbeds and high-K-Fe basalts. The 5.8 m.y. duration of basaltic volcanism in the Kimama drill core implies a steady rate of volcanism, indicating a relatively stable rate of mantle upflow along the lithosphere-mantle boundary in the wake of Yellowstone-Snake River Plain plume volcanism. © 2019 The Authors. Article 2019 English 1553040X 10.1130/GES01679.1 Geosphere 15 Geological Society of America 736 – 758 Department of Geology, Utah State University, Logan, UT 84321, United States; Volcano Science Center, U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025, United States; College of Earth, Ocean, and Atmospheric Sciences, Oregon State University, Corvallis, OR 97331, United States 3 Idaho; Snake River Plain; United States; Basalt; Binary alloys; Boreholes; Boring; Drills; Gamma rays; Geomagnetism; Infill drilling; Lead alloys; Neutron logging; Plastic flow; Rivers; Sediments; Silicate minerals; Stratigraphy; Uranium alloys; Volcanoes; Zircon; Accumulation rates; Basaltic volcanism; Heating experiment; Lithosphere mantle; Magnetostratigraphy; Paleosecular variations; Snake river plains; Volcanic activities; basalt; borehole; continental crust; facies; lava flow; lithology; magnetic reversal; magnetostratigraphy; paleomagnetism; volcanism; Core drilling https://www.scopus.com/inward/record.uri?eid=2-s2.0-85066821515&doi=10.1130%2fGES01679.1&partnerID=40&md5=ad25ec54bb2b205a9799d084d665e9db Cited by: 3; All Open Access, Gold Open Access, Green Open Access Katherine E. Potter Duane E. Champion Robert A. Duncan John W. Shervais article Gallant2018895 We present a new probabilistic lava flow hazard assessment for the U.S. Department of Energy's Idaho National Laboratory (INL) nuclear facility that (1) explores the way eruptions are defined and modeled, (2) stochastically samples lava flow parameters from observed values for use in MOLASSES, a lava flow simulator, (3) calculates the likelihood of a new vent opening within the boundaries of INL, (4) determines probabilities of lava flow inundation for INL through Monte Carlo simulation, and (5) couples inundation probabilities with recurrence rates to determine the annual likelihood of lava flow inundation for INL. Results show a 30% probability of partial inundation of the INL given an effusive eruption on the eastern Snake River Plain, with an annual inundation probability of 8.4 × 10-5 to 1.8 × 10-4. An annual probability of 6.2 × 10-5 to 1.2 × 10-4 is estimated for the opening of a new eruptive center within INL boundaries. © 2018 Geological Society of America. 2018 English 00917613 10.1130/G45123.1 Geology 46 Geological Society of America 895-898 School of Geosciences, University of South Florida, 4202 E. Fowler Avenue, Tampa, FL 33620, United States; Planetary Geology, Geophysics and Geochemistry Laboratory, NASA Goddard Space Flight Center, 8800 Greenbelt Road, Greenbelt, MD 20771, United States; Department of Astronomy, University of Maryland, College Park, MD 20742, United States 10 Floods; Intelligent systems; Monte Carlo methods; Probability, Annual probabilities; Effusive eruptions; Hazard Assessment; Idaho national laboratories; Nuclear facilities; Recurrence rates; Snake river plains; U.S. Department of Energy, Hazards https://www.scopus.com/inward/record.uri?eid=2-s2.0-85054126074&doi=10.1130%2fG45123.1&partnerID=40&md5=227aa23c0300c0c73e26ee341c5a7d7d cited By 15 E. Gallant J. Richardson C. Connor P. Wetmore L. Connor article Potter2018 Basalts erupted in the Snake River Plain of central Idaho and sampled in the Kimama drill core link eruptive processes to the construction of mafic intrusions over 5.5Ma. Cyclic variations in basalt composition reveal temporal chemical heterogeneity related to fractional crystallization and the assimilation of previously-intruded mafic sills. A range of compositional types are identified within 1,912m of continuous drill core: Snake River olivine tholeiite (SROT), low K SROT, high Fe-Ti, and evolved and high K-Fe lavas similar to those erupted at Craters of the Moon National Monument. Detailed lithologic and geophysical logs document 432 flow units comprising 183 distinct lava flows and 78 flowgroups. Each lava flowrepresents a single eruptive episode, while flow groups document chemically and temporally related flows that formed over extended periods of time. Temporal chemical variation demonstrates the importance of source heterogeneity and magma processing in basalt petrogenesis. Low-K SROT and high Fe-Ti basalts are genetically related to SROT as, respectively, hydrothermally-altered and fractionated daughters. Cyclic variations in the chemical composition of Kimama flow groups are apparent as 21 upward fractionation cycles, six recharge cycles, eight recharge-fractionation cycles, and five fractionation-recharge cycles. We propose that most Kimama basalt flows represent typical fractionation and recharge patterns, consistent with the repeated influx of primitive SROT parental magmas and extensive fractional crystallization coupled with varying degrees of assimilation of gabbroic to ferrodioritic sills at shallow to intermediate depths over short durations. Trace element models show that parental SROT basalts were generated by 5–10% partial melting of enriched mantle at shallow depths above the garnet-spinel lherzolite transition. The distinctive evolved and high K-Fe lavas are rare. Found at four depths, 319, 1045, 1,078, and 1,189m, evolved and high K-Fe flows are compositionally unrelated to SROT magmas and represent highly fractionated basalt, probably accompanied by crustal assimilation. These evolved lavas may be sourced from the Craters of the Moon/Great Rift system to the northeast. The Kimama drill core is the longest record of geochemical variation in the central Snake River Plain and reinforces the concept of magma processing in a layered complex. © 2018 Potter, Shervais, Christiansen and Vetter. 2018 English 22966463 10.3389/feart.2018.00010 Frontiers in Earth Science 6 Frontiers Media S.A. Department of Geology, Utah State University, Logan, UT, United States; Department of Geological Sciences, Brigham Young University, Provo, UT, United States; Department of Geology, Centenary College of Louisiana, Shreveport, LA, United States Basalt; Binary alloys; Drills; Infill drilling; Iron alloys; Moon; Olivine; Petrology; Rivers; Titanium alloys; Trace elements, Chemical compositions; Chemical heterogeneities; Drill core; Fractional crystallization; Geochemical variations; Mid-crustal sill complex; Snake river plains; Tholeiite, Core drilling, basalt; crystal structure; data assimilation; fractional crystallization; hydrothermal alteration; magma; petrogenesis; petrology; tholeiitic basalt, Idaho; Snake River Plain; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-85043571691&doi=10.3389%2ffeart.2018.00010&partnerID=40&md5=210aa79559b5fc4730547b0a04474401 cited By 14 K.E. Potter J.W. Shervais E.H. Christiansen S.K. Vetter article Colón20181 We present new high-precision CA-ID-TIMS and in situ U–Pb ages together with Hf and O isotopic analyses (analyses performed all on the same grains) from four tuffs from the 15−10 Ma Bruneau–Jarbidge center of the Snake River Plain and from three rhyolitic units from the Kimberly borehole in the neighboring 10−6 Ma Twin Falls volcanic center. We find significant intrasample diversity in zircon ages (ranges of up to 3 Myr) and in δ18 O (ranges of up to 6‰) and εHf (ranges of up to 24 ε units) values. Zircon rims are also more homogeneous than the associated cores, and we show that zircon rim growth occurs faster than the resolution of in situ dating techniques. CA-ID-TIMS dating of a subset of zircon grains from the Twin Falls samples reveals complex crystallization histories spanning 104 –106 years prior to some eruptions, suggesting that magma genesis was characterized by the cyclic remelting of buried volcanic rocks and intrusions associated with previous magmatic episodes. Age-dependent trends in zircon isotopic compositions show that rhyolite production in the Yellowstone hotspot track is driven by the mixing of mantle-derived melts (normal δ18 O and εHf) and a combination of Precambrian basement rock (normal δ18 O and εHf down to − 60) and shallow Mesozoic and Cenozoic age rocks, some of which are hydrothermally altered (to low δ18 O values) by earlier stages of Snake River Plain magmatism. These crustal melts hybridize with juvenile basalts and rhyolites to produce the erupted rhyolites. We also observe that the Precambrian basement rock is only an important component in the erupted magmas in the first eruption at each caldera center, suggesting that the accumulation of new intrusions quickly builds an upper crustal intrusive body which is isolated from the Precambrian basement and evolves towards more isotopically juvenile and lower-δ18 O compositions over time. © Springer-Verlag GmbH Germany, part of Springer Nature 2018. 2018 English 00107999 10.1007/s00410-017-1437-y Contributions to Mineralogy and Petrology 173 Springer Science and Business Media Deutschland GmbH 1-18 University of Oregon, Eugene, OR, United States; Department of Earth Sciences, Institute of Geochemistry and Petrology, ETH Zürich, Zurich, Switzerland; Brigham Young University, Provo, UT, United States; University of Alberta, Edmonton, AB, Canada 2 geochronology; hafnium; isotopic analysis; magma; oxygen isotope; rhyolite; tuff; uranium-lead dating; zircon, Idaho; Snake River Plain; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-85044293111&doi=10.1007%2fs00410-017-1437-y&partnerID=40&md5=ea35dcee789b198e52d51cab12785f64 cited By 20 D.P. Colón I.N. Bindeman J.-F. Wotzlaw E.H. Christiansen R.A. Stern article Hughes201889 Physical and compositional measurements are made at the ~ 7 km-long (~ 2200 years B.P.) Kings Bowl basaltic fissure system and surrounding lava field in order to further understand the interaction of fissure-fed lavas with phreatic explosive events. These assessments are intended to elucidate the cause and potential for hazards associated with phreatic phases that occur during basaltic fissure eruptions. In the present paper we focus on a general understanding of the geological history of the site. We utilize geospatial analysis of lava surfaces, lithologic and geochemical signatures of lava flows and explosively ejected blocks, and surveys via ground observation and remote sensing. Lithologic and geochemical signatures readily distinguish between Kings Bowl and underlying pre-Kings Bowl lava flows, both of which comprise phreatic ejecta from the Kings Bowl fissure. These basalt types, as well as neighboring lava flows from the contemporaneous Wapi lava field and the older Inferno Chasm vent and outflow channel, fall compositionally within the framework of eastern Snake River Plain olivine tholeiites. Total volume of lava in the Kings Bowl field is estimated to be ~ 0.0125 km3, compared to a previous estimate of 0.005 km3. The main (central) lava lake lost a total of ~ 0.0018 km3 of magma by either drain-back into the fissure system or breakout flows from breached levees. Phreatic explosions along the Kings Bowl fissure system occurred after magma supply was cut off, leading to fissure evacuation, and were triggered by magma withdrawal. The fissure system produced multiple phreatic explosions and the main pit is accompanied by others that occur as subordinate pits and linear blast corridors along the fissure. The drop in magma supply and the concomitant influx of groundwater were necessary processes that led to the formation of Kings Bowl and other pits along the fissure. A conceptual model is presented that has relevance to the broader range of low-volume, monogenetic basaltic fissure eruptions on Earth, the Moon and other planetary bodies. © 2018 Elsevier B.V. 2018 English 03770273 10.1016/j.jvolgeores.2018.01.001 Journal of Volcanology and Geothermal Research 351 Elsevier B.V. 89-104 Department of Geosciences, Idaho State University, 921 South 8th Avenue, Stop 8072, Pocatello, ID 83209, United States; NASA Ames Research Center, Mountain View, CA 94035, United States; Bay Area Environmental Research Institute, Petaluma, CA 94952, United States; NASA Goddard Space Flight Center, Geology, Geophysics and Geochemistry Lab, Greenbelt, MD 20771, United States; Department of Geological Sciences, Brigham Young University, Provo, UT 84602, United States; Mars Space Flight Facility, Arizona State University, Tempe, AZ 85287, United States Basalt; Geochemical surveys; Geochemistry; Groundwater; Lakes; Moon; Remote sensing; Silicate minerals, Fissure eruptions; Geo-spatial analysis; Geochemical signatures; Geological history; Ground observations; Phreatic explosions; Pit craters; Snake river plains, Explosions, basalt; crater; fissure; lava flow; magma; volcanic eruption, Idaho; Snake River Plain; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-85044639442&doi=10.1016%2fj.jvolgeores.2018.01.001&partnerID=40&md5=fed97740432e480174b8c49a860e1352 cited By 8 S.S. Hughes S.E. Kobs Nawotniak D.W.G. Sears C. Borg W.B. Garry E.H. Christiansen C.W. Haberle D.S.S. Lim J.L. Heldmann article Wilke2017789 The position of the cotectic curve separating quartz and feldspar stability fields in the rhyolite system Qz-Ab-Or(-An-H2O) depends on pressure, making it a potential geobarometer applicable to high-silica volcanic products if melt water contents (H2Omelt) are known. Until recently, the applicability of this geobarometer has been limited because pressure effects can be largely obscured by the effects of nearly ubiquitous normative anorthite (An, CaAl2Si2O8) in rhyolitic melts. In this study, we present new phase equilibria data that allow us to constrain the position of thermal minima and quartz-sanidine-plagioclase triple points on the quartz-feldspar cotectic curves at various pressures and melt normative An contents. Data were derived by conducting crystallization experiments to determine phase relations at the following conditions: 200 MPa, 1·4wt%H2Omelt, 3·5wt% An; 200 MPa, 1·3wt % H2Omelt, 7 wt % An; 500 MPa, 3wt % H2Omelt, 3·5wt % An; 500 MPa, 1·4wt % H2Omelt, 3·5wt % An; 500 MPa, 1·3wt%H2Omelt, 7 wt % An. Using this dataset with published phase equilibria results, we present a geobarometer based on the main parameters influencing cotectic compositions in the rhyolitic system: pressure, H2Omelt and melt An content. Our new geobarometer DERP (DEtermining Rhyolite Pressures) is calibrated to calculate pressures of magma storage from cotectic glass compositions with up to 7wt % normative melt An. DERP is calibrated for any H2Omelt in the pressure range 50-500 MPa. Its application is restricted to high-silica rhyolitic systems saturated with respect to quartz and feldspar(s). DERP was tested against various independent methods for estimating rhyolite pressures available in the literature (with an overall error of less than 100 MPa). Comparing pressures estimated with DERP and rhyolite-MELTS, which are based on the same approach, suggests that rhyolite-MELTS underestimates the effect of An. © The Author 2017. Published by Oxford University Press. All rights reserved. 2017 English 00223530 10.1093/petrology/egx034 Journal of Petrology 58 Oxford University Press 789-818 Leibniz Universität Hannover, Institut für Mineralogie, Callinstraße 3, Hannover, 30167, Germany 4 anorthite; crystallization; feldspar; geobarometry; magma; meltwater; petrology; phase equilibrium; quartz; rhyolite https://www.scopus.com/inward/record.uri?eid=2-s2.0-85027138383&doi=10.1093%2fpetrology%2fegx034&partnerID=40&md5=f7933973ad95715250b4c48909558ebb cited By 27 S. Wilke F. Holtz D.A. Neave R. Almeev article Kessler2017476 Project HOTSPOT, the Snake River Scientific Drilling Project (International Continental Scientific Drilling Program), tested for deep geothermal resources and examined the petrology of volcanic rocks with three drillholes in the central and western Snake River Plain (western USA). The MH-2 drillhole targeted fractured crystalline and hydrothermally altered basalt in the area of the Mountain Home Air Force Base (Idaho) to a total depth of 1821 m. At 1745 m depth the drillhole encountered flowing artesian hydrothermal fluids of at least 150 °C. We integrate geological analyses of core, image log, and borehole geophysical data, and in situ stress analyses to describe the structural environment that produces permeability for artesian flow. The rocks in the lower 540 m of the drillhole consist of basalt flows as much as 30 m thick, altered basalt, and thin sedimentary horizons. The mechanical stratigraphy is defined by nine mechanical horizons that are in three ranges of rock strength on the basis of experimentally determined strength data, core logging, and geophysical log signatures. Hydrothermal alteration products and mineralization in the core are associated with three highly faulted sections; the lowermost section is associated with the zone of flowing thermal water. Shear slip indicators on faults observed in core indicate slip ranging from pure strike slip to normal failure mechanisms in the stronger horizons. The borehole breakouts indicate that the maximum horizontal stress, SH, is oriented 047° ± 7°, and drilling-induced tensile fractures indicate that SH is oriented at 67° ± 21°.The in situ stress orientations exhibit little variation over the depth of the measured interval, but the SH magnitude varies with depth, and is best explained by an oblique normal fault stress regime.The geomechanical model indicates that if pore pressures at depth are elevated above the normal hydrostatic gradient, as observed here, the system has the potential to deform by mixed normal and strike-slip failure. Our observations and interpretations suggest that the MH-2 borehole was drilled into oblique normal faults that intersect a buried 300°-trending fault block masked by the basaltic volcanic complex. These data indicate that the transition from the central to western Snake River Plain is characterized by complex structures developed in response to a transitional stress state related to Snake River Plain and western Basin and Range stress regimes. The western Basin and Range stress and tectonic regime may extend from northern Nevada into western Idaho and may enhance the potential for geothermal resources by creating interconnected fracture and fault-related permeability at depth. © 2017 Geological Society of America. Article 2017 English 19418264 10.1130/L609.1 Lithosphere 9 Geological Society of America 476 – 498 Department of Geology, Utah State University, 4505 Old Main Hill, Logan, UT 84322, United States; Department of Physics, University of Alberta, 4-181 CCIS, Edmonton, AB T6G 2E1, Canada; Occidental Petroleum Corporation, 5 Greenway Plaza, Houston, TX 77046, United States; Anadarko Petroleum Company, 1201 Lake Robbins Drive, The Woodlands, TX 77380, United States 3 Idaho; Snake River Plain; United States; Air; Basalt; Boreholes; Boring; Clay alteration; Core analysis; Faulting; Fracture; Geology; Geophysics; Geothermal fields; Geothermal prospecting; Horizontal drilling; Rivers; Rock drills; Sedimentary rocks; Software testing; Stratigraphy; Stresses; Strike-slip faults; Structural geology; Volcanic rocks; Volcanoes; Well logging; Continental scientific drillings; Drilling-induced tensile fractures; Geothermal exploration; Hydrostatic gradients; Hydrothermal alterations; Mechanical stratigraphy; Sedimentary horizons; Structural environment; artesian well; borehole geophysics; geological survey; geomechanics; geothermal system; hydrothermal activity; hydrothermal fluid; in situ stress; petrology; strike-slip fault; Fault slips https://www.scopus.com/inward/record.uri?eid=2-s2.0-85019883682&doi=10.1130%2fL609.1&partnerID=40&md5=98f280eff23cf4b3e1bafa8596f7e582 Cited by: 9; All Open Access, Bronze Open Access, Green Open Access J.A. Kessler K.K. Bradbury J.P. Evans M.A. Pulsipher J.W. Shervais F.E. Rowe J. Varriale article Lachmar2017 A 1912-m exploration corehole was drilled along the axis of the eastern Snake River Plain, Idaho. Two temperature logs run on the corehole display an obvious inflection point at about 960 m. Such behavior is indicative of downward fluid flow in the wellbore. The geothermal gradient above 935 m is 4.5 °C/km, while the gradient is 72–75 °C/km from 980 to 1440 m. Projecting the higher gradients upward to where they intersect the lower gradient on the temperature logs places the bottom of the cold, freshwater Snake River Plain aquifer, which suppresses the geothermal gradient at this location, at least 860 m below the surface. The average heat flow for the corehole between 983 and 1550 m is 132 mW/m2. Although the maximum bottom-hole temperature extrapolated from a measured time–temperature curve was only 59.3 °C, geothermometers suggest an equilibrium temperature on the order of 125–140 °C based on a single fluid sample from 1070 m. Furthermore, below 960 m the basalt core shows obvious signs of alteration, including a distinct color change, the formation of smectite clay, and the presence of secondary minerals filling vesicles and fracture zones. This alteration boundary could act as an effective cap or seal for a hot-water geothermal system. © 2017, The Author(s). 2017 English 21959706 10.1186/s40517-017-0086-8 Geothermal Energy 5 SpringerOpen Department of Geology, Utah State University, Logan, UT 84322-4505, United States; Department of Earth Sciences, Syracuse University, Syracuse, NY 13244, United States; Department of Earth Science & Geography, Vassar College, Poughkeepsie, NY 12604, United States; Department of Earth Sciences, Southern Methodist University, Dallas, TX 75275-0395, United States; DOSECC Exploration Services, LLC, 2075 Pioneer Road, Salt Lake City, UT 84104, United States 1 Aquifers; Basalt; Clay alteration; Flow of fluids; Geothermal fields; Geothermal logging; Rivers; Water; X ray diffraction, Bottom hole temperatures; Corehole; Equilibrium temperatures; Freshwater aquifer; Geothermal gradients; Geothermal potential; Geothermometers; Temperature log, Thermal logging, aquifer; basalt; geothermal system; geothermometry; heat flow; temperature gradient; thermal alteration; X-ray diffraction, Idaho; Snake River Plain; United States, Calluna vulgaris https://www.scopus.com/inward/record.uri?eid=2-s2.0-85038103911&doi=10.1186%2fs40517-017-0086-8&partnerID=40&md5=bd74d4c9eef37ed62bf07cab26bfe4e9 cited By 5 T.E. Lachmar T.G. Freeman C.J. Sant J.R. Walker J.F. Batir J.W. Shervais J.P. Evans D.L. Nielson D.D. Blackwell article Knott20161121 The 1.95-km-thick Cassia Formation, defined in the Cassia Hills at the southern margin of the Snake River Plain, Idaho, consists of 12 refined and newly described rhyolitic members, each with distinctive field, geochemical, mineralogical, geochronological, and paleomagnetic characteristics. It records voluminous high-temperature, Snake River-type explosive eruptions between ca. 11.3 Ma and ca. 8.1 Ma that emplaced intensely welded rheomorphic ignimbrites and associated ash-fall layers. One ignimbrite records the ca. 8.1 Ma Castleford Crossing eruption, which was of supereruption magnitude (~1900 km3). It covers 14,000 km2 and exceeds 1.35 km thickness within a subsided, proximal caldera-like depocenter. Majorand trace-element data define three successive temporal trends toward less-evolved rhyolitic compositions, separated by abrupt returns to more-evolved compositions. These cycles are thought to reflect increasing mantle- derived basaltic intraplating and hybridization of a midcrustal region, coupled with shallower fractionation in upper-crustal magma reservoirs. The onset of each new cycle is thought to record renewed intraplating at an adjacent region of crust, possibly as the North American plate migrated westward over the Yellowstone hotspot. A regional NE-trending monocline, here termed the Cassia monocline, was formed by synvolcanic deformation and subsidence of the intracontinental Snake River basin. Its structural and topographic evolution is reconstructed using thickness variations, offlap relations, and rheomorphic transport indicators in the successive dated ignimbrites. The subsidence is thought to have occurred in response to incremental loading and modification of the crust by the mantle-derived basaltic magmas. During this time, the area also underwent NW-trending faulting related to opening of the western Snake River rift and E-W Basin and Range extension. The large eruptions probably had different source locations, all within the subsiding basin. The proximal Miocene topography was thus in marked contrast to the more elevated present-day Yellowstone plateau. © 2016 Geological Society of America. 2016 English 00167606 10.1130/B31324.1 Bulletin of the Geological Society of America 128 Geological Society of America 1121-1146 Department of Geology, University of Leicester, Leicester, LE1 7RH, United Kingdom; Earth and Planetary Science Department, University of California, Santa Cruz, CA 95064, United States; Quaternary Dating Laboratory, Natural History Museum of Denmark, University of Copenhagen, Copenhagen, 2100, Denmark; Scottish Universities Environmental Research Centre, East Kilbride, G75 0QF, United Kingdom; Department of Geosciences, Idaho State University, Pocatello, ID 83209, United States 7 Explosives; Geochronology; Subsidence; Trace elements, Explosive eruption; Explosive volcanism; Miocene topography; North american plates; Snake river plains; Thickness variation; Transport indicators; Yellowstone hotspot, Rivers, explosive volcanism; geochemistry; geochronology; mineralogy; Miocene; paleomagnetism; rhyolite; subsidence; hot spot; ignimbrite; trace element; volcanology, Idaho; Snake River Plain; United States; Wyoming; Yellowstone Caldera https://www.scopus.com/inward/record.uri?eid=2-s2.0-84977485066&doi=10.1130%2fB31324.1&partnerID=40&md5=9c1e1b32a2e212549be4f86d3d2d4572 cited By 25 T.R. Knott M.J. Branney M.K. Reichow D.R. Finn R.S. Coe M. Storey D. Barfod M. McCurry article Walker2016691 The MH-2B borehole, a part of Project HOTSPOT, was drilled to a depth of 1821 m in late Cenozoic basalts, hyaloclastites and interbedded lake sediments, on the Mountain Home Air Force Base in southern Idaho, USA. Drillers encountered hot water (145°C) under artesian pressure at 1745 m in a narrow zone of highly fractured rock associated with a major sub-surface fault. X-ray diffraction (XRD) analysis identified corrensite (with and without smectite) between 1700 and 1800 m, but only smectite above 1700 m and below 1800 m. This corrensite horizon contains a relatively narrow zone of fracturing and hot artesian water near its centre but for the most part occurs in relatively massive basalt flows. No evidence was found for randomly interstratified chlorite-smectite. © 2016 by Walter de Gruyter Berlin/Boston. 2016 English 00098558 10.1180/claymin.2016.051.4.10 Clay Minerals 51 Mineralogical Society 691-696 Department of Earth Science and Geography, Vassar College, Poughkeepsie, NY, United States 4 X ray diffraction analysis, Air Force Base; Artesian pressure; Corrensite; Hyaloclastites; Lake sediments; Project hotspot; Smectites; Snake river plains, Basalt, artesian well; basalt; borehole breakout; Cenozoic; corrensite; hyaloclastite; hydrothermal alteration; lacustrine deposit; smectite, Idaho; Snake River Plain; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-85008192160&doi=10.1180%2fclaymin.2016.051.4.10&partnerID=40&md5=0e56fac4dc6d518043f4168b0c491dc1 cited By 2 J. Walker J. Wheeler article Moody2016115 Geothermal energy depends on high subsurface temperature, adequate permeability and fracture volume, and accessible groundwater supply to support heat exchange with surrounding rock. Some regions may have adequate thermal resources but lack the necessary permeability or deep circulating water. Exploitation of such areas for geothermal energy could occur if permeability can be enhanced enough to provide the necessary heat exchange. These improvements to the geothermal reservoir would produce what is termed an "enhanced geothermal system" (EGS). The Snake River Plain (SRP) in southern Idaho is a geological region with high heat flux (~110 mW/m2) that has been recommended as an EGS target. In this study, we consider how the geologic and thermal history of the SRP might influence its EGS potential. We describe the fracture distribution (mean = 28.63 fractures/10 m) in a welded tuff core recovered from one of the few deep boreholes located on the SRP and provide a preliminary discussion of the likely geomechanical behavior under in situ stress. Spatial autocorrelation of fracture features is defined with geostatistical techniques and used in a stochastic simulation of possible structures in other welded tuff reservoirs. Autocorrelation scales for the continuous date are on the order of 70 meters with high subsample scale variability (56 m). Results should aid in designing criteria for a hydraulic fracturing plan that would augment the permeability and connectivity of an SRP reservoir's preexisting fracture network. © 2016 The Geological Society of America. All rights reserved. 2016 English 9780813725192 00721077 10.1130/2016.2519(08) Special Paper of the Geological Society of America 519 Geological Society of America Dowling C.B., Florea L.J., Neumann K. 115-136 Department of Geological Sciences, University of Idaho, 875 Perimeter Drive, MS 3022, Moscow, ID 83844, United States; Idaho National Laboratory, Earth Resources Recovery and Sustainability, 2525 Fremont Avenue, Idaho Falls, ID, United States Autocorrelation; Boreholes; Fracture; Geothermal fields; Geothermal wells; Groundwater; Heat exchangers; Heat flux; Hydraulic fracturing; Petroleum reservoir engineering; Stochastic models; Stochastic systems; Welding, Enhanced geothermal systems; Fracture distributions; Geomechanical behavior; Geostatistical techniques; Preexisting fracture; Spatial autocorrelations; Stochastic simulations; Subsurface temperature, Geothermal energy, fracture network; geothermal power; geothermal system; groundwater exploration; heat flux; hydraulic fracturing; permeability; reservoir; surface temperature, Idaho; Idaho; Snake River Plain; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-84971377828&doi=10.1130%2f2016.2519%2808%29&partnerID=40&md5=d964eb00f94fcbdea8329227ccdbfb45 cited By 0 A. Moody J. Fairley M. Plummer article McLing2016144 A map of groundwater temperatures from the Eastern Snake River Plain (ESRP) regional aquifer can be used to identify and interpret important features of the aquifer, including aquifer flow direction, aquifer thickness, and potential geothermal anomalies. The ESRP is an area of high heat flow, yet most of this thermal energy fails to reach the surface, due to the heat being swept downgradient by the aquifer to the major spring complexes near Thousand Springs, ID, a distance of 300 km. Nine deep boreholes that fully penetrate the regional aquifer display three common features: (1) high thermal gradients beneath the aquifer, corresponding to high conductive heat flow in low-permeability hydrothermally-altered rocks; (2) isothermal temperature profiles within the aquifer, characteristic of an actively flowing groundwater; and (3) moderate thermal gradients in the vadose zone with values that indicate that over half of the geothermal heat flow is removed by advective transport in the regional aquifer system. This study utilized temperature data from 250 ESRP aquifer wells to evaluate regional aquifer flow direction, aquifer thickness, and potential geothermal anomalies. Because the thermal gradients are typically low in the aquifer, any measurement of groundwater temperature is a reasonable estimate of temperature throughout the aquifer thickness, allowing the construction of a regional aquifer temperature map for the ESRP. Mapped temperatures are used to identify cold thermal plumes associated with recharge from tributary valleys and adjacent uplands, and warm zones associated with geothermal input to the aquifer. Warm zones in the aquifer can have various causes, including local circulation of groundwater through the deep conductively dominated region, slow groundwater movement in low-permeability regions, or localized heat flow from deeper thermal features. © 2015 Elsevier B.V. 2016 English 03770273 10.1016/j.jvolgeores.2016.04.006 Journal of Volcanology and Geothermal Research 320 Elsevier B.V. 144-155 Idaho National Laboratory, P.O. Box 1625, Idaho Falls, ID 83415-2107, United States; The Center for Advanced Energy Studies, 995 University Blvd, Idaho Falls, ID 83401, United States; Smith Geologic and Photographic Services, LLC, Nathrop, CO 81236, United States; University of Idaho, Moscow, ID 83844, United States; Earth and Environmental Sciences Division, Los Alamos National Laboratory, Los Alamos, NM 87545, United States Aquifers; Boreholes; Geothermal energy; Geothermal heating; Groundwater; Groundwater flow; Heat transfer; Rivers; Temperature distribution; Thermal gradients, Advective transport; Geothermal potential; Ground water movement; Groundwater temperatures; Hydrothermally altered rocks; Isothermal temperature; Snake river plains; Thermal groundwater, Groundwater resources, aquifer; flow modeling; groundwater; heat flow; permeability; temperature profile; tracer, Idaho; Snake River Plain; United States, Calluna vulgaris https://www.scopus.com/inward/record.uri?eid=2-s2.0-84965053138&doi=10.1016%2fj.jvolgeores.2016.04.006&partnerID=40&md5=05fdc3b4dcecd0d63439ee1e025113fd cited By 9 T.L. McLing R.P. Smith R.W. Smith D.D. Blackwell R.C. Roback A.J. Sondrup article 10.1127/ejm/2015/0027-2423 {The effect of the normative anorthite content on the position of cotectic curves in the Qz–Ab–Or–An system has been investigated at 200 MPa and a water activity of 0.5. To simulate compositions as close as possible to those of natural high-silica rhyolites, all investigated compositions also contained ~ 1 wt\% FeO and 0.2 wt\% TiO2. The position of the cotectic curves was deduced from crystallization experiments carried out between 790 and 850°C and using fourteen starting glass compositions containing ~ 3 wt\% H2O. The liquidus phase of the different starting materials was used to constrain the primary fields of quartz, plagioclase and sanidine. The compositions of residual melts coexisting with solid phases were used to define the position of cotectic curves. Compared to the haplogranite system, the eutectic point is shifted away from the Ab apex, and its composition is estimated to be Qz42Ab21Or37 when projected onto the haplogranite system. The implications for the estimation of the depth of magma storage conditions are discussed on the basis of an example from the Snake River Plain high-silica rhyolites.} 2015 03 0935-1221 10.1127/ejm/2015/0027-2423 European Journal of Mineralogy 27 147-159 2 https://doi.org/10.1127/ejm/2015/0027-2423 Sören Wilke Carolin Klahn Torsten Bolte Renat Almeev François Holtz article Wiesmaier20151007 In order to explore the materials' complexity induced by bubbles rising through mixing magmas, bubble-advection experiments have been performed, employing natural silicate melts at magmatic temperatures. A cylinder of basaltic glass was placed below a cylinder of rhyolitic glass. Upon melting, bubbles formed from interstitial air. During the course of the experimental runs, those bubbles rose via buoyancy forces into the rhyolitic melt, thereby entraining tails of basaltic liquid. In the experimental run products, these plume-like filaments of advected basalt within rhyolite were clearly visible and were characterised by microCT and high-resolution EMP analyses. <br><br> The entrained filaments of mafic material have been hybridised. Their post-experimental compositions range from the originally basaltic composition through andesitic to rhyolitic composition. Rheological modelling of the compositions of these hybridised filaments yield viscosities up to 2 orders of magnitude lower than that of the host rhyolitic liquid. Importantly, such lowered viscosities inside the filaments implies that rising bubbles can ascend more efficiently through pre-existing filaments that have been generated by earlier ascending bubbles. MicroCT imaging of the run products provides textural confirmation of the phenomenon of bubbles trailing one another through filaments. This phenomenon enhances the relevance of bubble advection in magma mixing scenarios, implying as it does so, an acceleration of bubble ascent due to the decreased viscous resistance facing bubbles inside filaments and yielding enhanced mass flux of mafic melt into felsic melt via entrainment. In magma mixing events involving melts of high volatile content, bubbles may be an essential catalyst for magma mixing. <br><br> Moreover, the reduced viscosity contrast within filaments implies repeated replenishment of filaments with fresh end-member melt. As a result, complex compositional gradients and therefore diffusion systematics can be expected at the filament-host melt interface, due to the repetitive nature of the process. However, previously magmatic filaments were tacitly assumed to be of single-pulse origin. Consequently, the potential for multi-pulse filaments has to be considered in outcrop analyses. As compositional profiles alone may remain ambiguous for constraining the origin of filaments, and as 3-D visual evidence demonstrates that filaments may have experienced multiple bubbles passages even when featuring standard diffusion gradients, therefore, the calculation of diffusive timescales may be inadequate for constraining timescales in cases where bubbles have played an essential role in magma mixing. Data analysis employing concentration variance relaxation in natural samples can distinguish conventional single-pulse filaments from advection via multiple bubble ascent advection in natural samples, raising the prospect of yet another powerful application of this novel petrological tool. © 2015 Author(s). 2015 English 18699510 10.5194/se-6-1007-2015 Solid Earth 6 Copernicus GmbH 1007-1023 Dept. of Earth and Environmental Sciences, Ludwig-Maximilians-Universität München, Münich, 80333, Germany; GEOVOL, Universidad de Las Palmas de Gran Canaria, Las Palmas de Gran Canaria, 35017, Spain; Department of Physics and Geology, University of Perugia, Perugia, 06100, Italy; Research School of Earth Sciences, Australian National University, Canberra, ACT 0200, Australia; Earth Ocean and Ecological Sciences, University of Liverpool, Liverpool, L69 3GP, United Kingdom 3 Advection; Basalt; Cylinders (shapes); Glass; Mixing; Silicates; Viscosity, Compositional gradients; Diffusion gradients; Magmatic temperatures; Orders of magnitude; Reduced viscosity; Rheological modelling; Viscous resistance; Volatile contents, Computerized tomography, advection; bubble; chemical alteration; chemical composition; entrainment; experimental study; igneous geochemistry; magma assimilation; mixing; rhyolite; silicate melt https://www.scopus.com/inward/record.uri?eid=2-s2.0-84940029526&doi=10.5194%2fse-6-1007-2015&partnerID=40&md5=b2e077761c9c6882732b703f784e33dd cited By 15 S. Wiesmaier D. Morgavi C.J. Renggli D. Perugini C.P. De Campos K.-U. Hess W. Ertel-Ingrisch Y. Lavallée D.B. Dingwell article Liberty2015919 Hotspot: The Snake River Geothermal Drilling Project was undertaken to better understand geothermal systems across the Snake River Plain volcanic province. A series of surface and borehole seismic profiles were obtained to provide insights into volcanic stratigraphy and test the capabilities of engineering-scale seismic imaging in such terranes. The Kimberly site drilled through 1.9 km of mostly rhyolite, with thin sedimentary interbeds in the upper part of the section. The Kimama site drilled through 1.9 km of mostly basalt with sedimentary interbeds at ∼200 m depth and 1700 m depth. The Mountain Home site contained numerous sediment and volcanic rock layers. Downhole and surface vibroseis seismic results suggest sedimentary interbeds at depth correspond with low-velocity, high-temperature zones that relate to reflections on seismic profiles. Our results suggest that eruption flow volumes can be estimated and flow boundaries can be imaged with surface seismic methods using relatively high-fold and wide-angle coverage. High-frequency attenuation is observed at all sites, and this deficit may be countered by acquisition design and a focus on signal processing steps. Separation of surface and body waves was obtained by muting, and the potential for large static effects was identified and addressed in processing. An accurate velocity model and lithology contacts derived from borehole information improved the confidence of our seismic interpretations. © 2015 European Association of Geoscientists & Engineers. 2015 English 00168025 10.1111/1365-2478.12277 Geophysical Prospecting 63 919-936 Boise State University, Department of Geosciences, 1910 University Drive, Boise, ID 83725-1536, United States; Institute for Geophysical Research, Department of Physics, University of Alberta, Edmonton, AB T6G 2E1, Canada; Department of Geology, Utah State University, 4505 Old Main Hill, Logan, UT 843224905, United States 4 Boreholes; Geothermal fields; Geothermal wells; Infill drilling; Lithology; Rivers; Sedimentology; Seismic waves; Seismology; Signal processing; Stratigraphy; Volcanoes, Geothermal; Geothermal drilling; Geothermal systems; High frequency attenuation; High temperature zones; Seismic imaging; Seismic interpretation; Snake river plains, Volcanic rocks, body wave; borehole; data interpretation; geothermal system; imaging method; seismology; signal processing; volcanic rock, Idaho; Snake River Plain; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-84937978127&doi=10.1111%2f1365-2478.12277&partnerID=40&md5=b9b7f5079d15f25c6e9f5c05d1eba720 cited By 3 L.M. Liberty J.W. Shervais article Shervais2015761 The Snake River volcanic province (SRP) overlies a thermal anomaly that extends deep into the mantle; it represents one of the highest heat flow provinces in North America. Our goals for this Phase 1 study are to: (1) adapt the methodology of Play Fairway Analysis for geothermal exploration to create a formal basis for its application to geothermal systems, (2) assemble relevant data for the SRP from publicly available and private sources, and (3) build a geothermal play fairway model for the SRP and identify the most promising plays, using software tools that are standard in the petroleum industry. The success of play fairway analysis in geothermal exploration depends critically on defining a systematic methodology that is grounded in theory (as developed within the petroleum industry over the last two decades) and within the geologic and hydrologic framework of real geothermal systems. Our preliminary assessment of the data suggests that important undiscovered geothermal resources may be located in several areas of the SRP, including the western SRP (associated with buried lineaments defined by gravity or magnetic anomalies, and capped by extensive deposits of lacustrine sediment), at lineament intersections in the central SRP (along the Banbury-Hagerman trend N W of Twin Falls, and along the northern margin of the Mt Bennett Hills-Camas Prairie area), and along the margins of the eastern SRP. Additional high temperature resources are likely associated with rhyolite domes and crypto-domes in the eastern SRP, but are masked by shallow groundwater flow leading to low upper crustal heat flow values. These blind resources may be exploitable with existing deep drilling technology. Groundwater modeling planned for later phases of the PFA project will address whether temperatures at viable producing depths are sufficient to support electricity production. © Copyright (2015) by Geothermal Resources Council All rights reserved. 2015 English 9781510817241 01935933 Transactions - Geothermal Resources Council 39 Geothermal Resources Council 761-769 Department of Geology, Utah State University, Logan, UT, United States; US Geological Survey, Menlo Park, CA, United States; Center for Geophysical Investigation of Shallow Subsurface, Boise State University, Boise, ID, United States; Lawrence Berkeley National Laboratory, Berkeley, CA, United States; National Renewable Energy Laboratory, Golden, CO, United States; DOSECC Exploration Services, LLC., Salt Lake City, UT, United States; Leidos, Inc., San Diego, CA, United States; US Geological Survey, Portland, OR, United States Application programs; Domes; Geothermal fields; Geothermal wells; Groundwater; Groundwater flow; Groundwater resources; Heat transfer; Petroleum industry; Petroleum prospecting; Rivers; Structural geology, Electricity production; Geothermal exploration; Groundwater modeling; Idaho; Play fairway analysis; Preliminary assessment; Snake river plains; Systematic methodology, Geothermal prospecting https://www.scopus.com/inward/record.uri?eid=2-s2.0-84963994586&partnerID=40&md5=009779353fb4453be8913e6ebea395de cited By 3 J.W. Shervais J.M. Glen L.M. Liberty P. Dobson E. Gasperikova E. Sonnenthal C. Visser D. Nielson S. Garg J.P. Evans D. Siler J. Deangelo N. Athens E. Burns article Bolte2015 The magma storage conditions of the 6.62 Ma Blacktail Creek Tuff eruption, belonging to the Heise volcanic field (6.62–4.45 Ma old) of the Yellowstone hotspot system, have been investigated by combining thermobarometric and experimental approaches. The results from different geothermometers (e.g., Fe–Ti oxides, feldspar pairs, apatite and zircon solubility, and Ti in quartz) indicate a pre-eruptive temperature in the range 825–875 °C. The temperature estimated using two-pyroxene pairs varies in a range of 810–950 °C, but the pyroxenes are probably not in equilibrium with each other, and the analytical results of melt inclusion in pyroxenes indicate a complex history for clinopyroxene, which hosts two compositionally different inclusion types. One natural Blacktail Creek Tuff rock sample has been used to determine experimentally the equilibrium phase assemblages in the pressure range 100–500 MPa and a water activity range 0.1–1.0. The experiments have been performed at fluid-present conditions, with a fluid phase composed of H2O and CO2, as well as at fluid-absent conditions. The stability of the quartzo-feldspathic phases is similar in both types of experiments, but the presence of mafic minerals such as biotite and clinopyroxene is strongly dependent on the experimental approach. Possible explanations are given for this discrepancy which may have strong impacts on the choice of appropriate experimental approaches for the determination of magma storage conditions. The comparison of the composition of natural phases and of experimentally synthesized phases confirms magma storage temperatures of 845–875 °C. Melt water contents of 1.5–2.5 wt% H2O are required to reproduce the natural Blacktail Creek Tuff mineral assemblage at these temperatures. Using the Ti-in-quartz barometer and the Qz–Ab–Or proportions of natural matrix glasses, coexisting with quartz, plagioclase and sanidine, the depth of magma storage is estimated to be in a pressure range between 130 and 250 MPa. © 2015, Springer-Verlag Berlin Heidelberg. 2015 English 00107999 10.1007/s00410-015-1112-0 Contributions to Mineralogy and Petrology 169 Springer Verlag Institute of Mineralogy, Leibniz University of Hannover, Callinstraße 3, Hannover, 30167, Germany; Department of Geology and Geophysics, University of Utah, Salt Lake City, UT 84112-011, United States 2 clinopyroxene; hot spot; melt inclusion; meltwater; plagioclase; quartz; rhyolite; sanidine; temperature, Idaho; Snake River Plain; United States; Yellowstone Volcanic Plateau, Gymnocephalus cernuus https://www.scopus.com/inward/record.uri?eid=2-s2.0-84922252893&doi=10.1007%2fs00410-015-1112-0&partnerID=40&md5=542deb402f6566256c2512e26a5f1b91 cited By 28 T. Bolte F. Holtz R. Almeev B. Nash article osti_1236394 2014 2 10.2172/1236394 Report to Department of Energy Geothermal Technology Office https://www.osti.gov/biblio/1236394 John W. Shervais James P. Evans Lee M. Liberty David D. Blackwell article Jean2014119 The Snake River Plain represents 17 m.y. of volcanic activity that took place as the North American continent migrated over a relatively fixed magma source, or hotspot. We present new Pb, Sr, and Nd data for a suite of 25 basalts collected from Western and Central Snake River Plain (SRP). The new isotope data, combined with previously published data from the SRP, provide a traverse of the Wyoming craton margin, from the 87Sr/86Sr = 0.706 line boundary of western SRP with Phanerozoic accreted terranes, east through the central and eastern SRP, to the Yellowstone Plateau. Low-K basalts from the western SRP, overlain by high-K basalts, provide a temporal record of regional source variation from ~16.8 to 0.2 Ma. Principal Component Analysis (PCA) of the new and previously published SRP basalt Pb isotopes reveals that &gt;97% of the total variability is accounted for by mixing between three end-members and is consistent with a sublithospheric Yellowstone hotspot mantle source with a radiogenic isotope composition similar to the mantle source of the early Columbia River Basalt Group (CRBG) and two continental lithosphere end-members, heterogeneous in age and composition. We use the SRP Pb, Sr, and Nd isotope data to model the Yellowstone Hotspot-continental lithosphere interaction by three component mixing between two continental lithospheric components, Archean lithosphere (CL1) that represents older lithosphere underlying the Yellowstone Plateau in the east, and Paleoproterozoic lithosphere (CL2) representing the younger lithosphere underlying the SRP in the west near the craton margin, and a sublithospheric end-member, representing the Yellowstone hotspot (PL). The results suggest a continuous flow of PL material westward as the NA continental lithosphere migrated over the upwelling hotspot along a shoaling gradient in the sub-continental mantle lithosphere. The model shows a decrease in Total Lithosphere end-members (CL1 + CL2) and the Lithosphere Ratio (CL1/CL2), from the craton interior at Yellowstone toward its western margin, consistent with geologic and geophysical evidence that the continental lithosphere beneath the SRP decreases in age and thickness from east to west. The Lithosphere Ratio shows step-like decreases from Yellowstone in the east to the 87Sr/86Sr = 0.706 line in the west, indicating that the SRP cuts across geochemically distinct parcels of lithospheric mantle, consistent with terrane accretion models for the craton margin. In the western SRP, young high-K basalts have a lower mass fraction of Total Lithospheric compared to the underlying low-K tholeiites, but the same Lithosphere Ratio, consistent with a recent (700-900 ka) decrease in lithosphere contribution between eruption of early low- and younger high-K basalts. © 2013 Elsevier B.V. 2014 English 0012821X 10.1016/j.epsl.2013.12.012 Earth and Planetary Science Letters 389 119-131 Department of Geology, Utah State University, 4505 Old Main Hill, Logan, UT 84322-4500, United States; Department of Geological Sciences, San Diego State University, San Diego, CA 92182-1020, United States; Institut für Mineralogie, Leibniz Universität, Hannover, 30167, Germany Columbia river basalts; Continental lithosphere; Geophysical evidence; Plume dynamics; Snake river plains; Total variabilities; Volcanic activities; Yellowstones, Basalt; Isotopes; Lead; Lithology; Mixing; Principal component analysis; Rivers, Strontium, alkali basalt; continental lithosphere; craton; hot spot; igneous geochemistry; isotopic analysis; isotopic composition; lead isotope; neodymium isotope; plume; strontium isotope; terrane; tholeiitic basalt, Idaho; Snake River Plain; United States; Wyoming; Yellowstone Volcanic Plateau https://www.scopus.com/inward/record.uri?eid=2-s2.0-84892174388&doi=10.1016%2fj.epsl.2013.12.012&partnerID=40&md5=060460e1f77f9c5696587e73d525495b cited By 24 M.M. Jean B.B. Hanan J.W. Shervais article Shervais201485 The Yellowstone supervolcano erupted roughly 640,000 years ago, covering much of North America in a thick coat of ash. Material ejected from the volcano devastated the surrounding area, and particles injected into the atmosphere changed the Earth's climate. Over the past 18 million years the Yellowstone hot spot has powered a series of similar eruptions. In southern Idaho, the 640-kilometer-long Snake River Plain traces the path of the Yellowstone hot spot over this period. ©2014. American Geophysical Union. All Rights Reserved. 2014 English 00963941 10.1002/2014EO100001 Eos 95 American Geophysical Union 85-86 Utah State University, Logan, United States; University of Alberta, Edmonton, Canada; Brigham Young University, Provo, UT, United States; University of South Carolina, Columbia, United States 10 ash; climate change; drilling; hot spot; mantle plume; volcanic eruption; volcanic ash, Idaho; Snake River Plain; United States; Yellowstone Volcanic Plateau https://www.scopus.com/inward/record.uri?eid=2-s2.0-84899115855&doi=10.1002%2f2014EO100001&partnerID=40&md5=e892ceab8c63c614b7ac8379ea96fbc7 cited By 6 J.W. Shervais J.P. Evans E.H. Christiansen A. Prokopenko article Anders20142871 The Heise and Picabo volcanic fields of eastern Idaho are part of the more extensive time-transgressive Yellowstone-Snake River Plain hotspot track. Calderas associated with these two silicic volcanic fields are buried under 1 to 3 km of younger basalt, so their locations and eruption record histories have been based on analysis of silicic units along the margins of the eastern Snake River Plain along with some limited geophysical data. A 1.5 km borehole penetrating through basalt into underlying silicic rocks provides new data we used to reassess caldera locations and the timing of eruptions of these volcanic fields. Using these new caldera locations, we calculate an extension-adjusted rate of 2.35 cm/yr for the North American plate over the last 6.66 m.y. and a velocity of 2.30 cm/yr over the 10.27 m.y. Recalculation of a previously determined plate velocity-based migration of the deformation field surrounding the eastern Snake River Plain yields an extension-adjusted rate of 2.38 ± 0.21 cm/yr. These migration rates all fall within the previously published range of North American plate velocities of 2.2 ± 0.8 cm/yr, 2.4 cm/yr, and 2.68 ± 0.78 cm/yr based on a global hot spot reference frame. The consistency of these rates suggest that over the last 10 m.y., the Yellowstone hot spot is fixed with respect to the motion of the North American plate and therefore consistent with a classical deep-sourced hotspot model. ©2014. American Geophysical Union. All Rights Reserved. 2014 English 21699313 10.1002/2013JB010483 Journal of Geophysical Research: Solid Earth 119 Blackwell Publishing Ltd 2871-2906 Department of Earth and Environmental Sciences and Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, United States; Department of Geosciences, Idaho State University, Pocatello, ID, United States; Science Department, Red Hook High School, Red Hook, NY, United States; Department of Earth and Environmental Science, Long Island University, Brookville, NY, United States; U.S. Geological Survey, Menlo Park, CA, United States; Department of Geology, Brigham Young University Idaho, Rexburg, ID, United States; Department of Earth and Environment, Franklin and Marshall College, Lancaster, PA, United States 4 basalt; caldera; deformation; hot spot; ignimbrite; lithospheric structure; Neogene; North American plate; volcanic eruption; volcanic landform, Idaho; Snake River Plain; United States; Yellowstone River https://www.scopus.com/inward/record.uri?eid=2-s2.0-84901020438&doi=10.1002%2f2013JB010483&partnerID=40&md5=489f853cb6a6a54da01dded980e86d36 cited By 20 M.H. Anders D.W. Rodgers S.R. Hemming J. Saltzman V.J. Divenere J.T. Hagstrum G.F. Embree R.C. Walter article Shervais201336 HOTSPOT is an international collaborative effort to understand the volcanic history of the Snake River Plain (SRP). The SRP overlies a thermal anomaly, the Yellowstone-Snake River hotspot, that is thought to represent a deep-seated mantle plume under North America. The primary goal of this project is to document the volcanic and stratigraphic history of the SRP, which represents the surface expression of this hotspot, and to understand how it affected the evolution of continental crust and mantle. An additional goal is to evaluate the geothermal potential of southern Idaho. Project HOTSPOT has completed three drill holes. (1) The Kimama site is located along the central volcanic axis of the SRP; our goal here was to sample a long-term record of basaltic volcanism in the wake of the SRP hotspot. (2) The Kimberly site is located near the margin of the plain; our goal here was to sample a record of high-temperature rhyolite volcanism associated with the underlying plume. This site was chosen to form a nominally continuous record of volcanism when paired with the Kimama site. (3) The Mountain Home site is located in the western plain; our goal here was to sample the Pliocene-Pleistocene transition in lake sediments at this site and to sample older basalts that underlie the sediments. We report here on our initial results for each site, and on some of the geophysical logging studies carried out as part of this project. Article 2013 English 18168957 10.5194/sd-15-36-2013 Scientific Drilling Copernicus GmbH 36 – 45 Department of Geology, Utah State University, 4505 Old Main Hill, Logan, UT 84322-4505, United States; Department of Physics, CCIS 3-091, University of Alberta, Edmonton, AB, T6G 2E1, Canada; DOSECC, Inc., 2075 Pioneer Road, Suite B, Salt Lake City, UT 84104-4231, United States; Department of Geological Sciences, Brigham Young University, Provo, UT 84602, United States; U.S. Geological Survey, Central Mineral and Environmental Resources Science Center, Denver Federal Center, Box 25046, MS-973, Denver, CO 80225, United States; Center for Geophysical Investigation of the Shallow Subsurface, Boise State University, 1910 University Drive, Boise, ID 83725-1536, United States; Huffington Department of Earth Sciences, Southern Methodist University, P.O. Box 750395, Dallas, TX 75275-0395, United States; U.S. Geological Survey, 345 Middlefield Road, Menlo Park, CA 94025-3591, United States; Department of Earth and Ocean Sciences, University of South Carolina, Columbia, SC 29208, United States 15 Distributed computer systems; Infill drilling; Stratigraphy; Volcanoes; Basaltic volcanism; Continental crusts; Geophysical logging; Geothermal potential; Scientific drilling; Snake river plains; Surface expression; Thermal anomalies; Rivers https://www.scopus.com/inward/record.uri?eid=2-s2.0-84877816432&doi=10.5194%2fsd-15-36-2013&partnerID=40&md5=c3e1ecc424b53224ea759b52297a1d93 Cited by: 30; All Open Access, Gold Open Access, Green Open Access John W. Shervais Dennis Nielson James P. Evans Eric H. Christiansen Lisa Morgan W.C. Pat Shanks Alexander A. Prokopenko Thomas Lachmar Lee M. Liberty David D. Blackwell Jonathan M. Glen Duane Champion Katherine E. Potter James A. Kessler article Jean20131319 The temporal and magmatic evolution of central Snake River Plain (SRP; Idaho, USA) olivine tholeiites erupted within the past 4 m.y. is evaluated here. This investigation correlates and merges both geochemical and paleomagnetic measurements to constrain the volcanic history recovered from the 340 m Regional Aquifer Systems Analysis (RASA) test well located near Wendell, Idaho. Only a handful of studies have accomplished this task of shedding light on the chemical stratigraphy of the SRP and the petrogenesis of basalts with depth, and therefore through time. Paleomagnetic relationships suggest that time breaks between individual lava flows represent a few years to decades, time breaks between flow groups represent at least a couple of hundred years or possibly much longer, while significant hiatuses in volcanism, revealed by thick sediment packages or polarity reversals (both are evidenced in this well), are inferred to last thousands to tens of thousands of years. Major element geochemistry from 52 basaltic lava flows demonstrates near primitive compositions (i.e., ~10 wt% MgO) and tholeiitic iron enrichment trends, similar to lavas from the eastern SRP. Trace element concentrations are similar to those of ocean island basalts, with enriched Ba and Pb, and light rare earth element (REE)/heavy REE ratios similar to those of many Neogene volcanics of the western Cordillera. When combined, we identify a total of 11 flow groups, which we also classify as fractionation or recharge on the basis of decreasing or increasing MgO weight percent with depth. Taking into consideration these trends, we review the potential recharge, fractionation, and assimilation processes that characterize much of SRP olivine tholeiite, and conclude that assimilation, in combination with fractional crystallization, is the dominant petrogenesis for the basalts in the central SRP. Although fractionation of Wendell parent magmas was accompanied by assimilation of crustal material, this could not have been assimilation of ancient cratonic crust. The geochemical cycles observed in this well are inferred to represent fractionation and recharge of basaltic magma from a series of sill-like layered mafic intrusions located in the middle crust, similar to what has been proposed for the processes that control the eruptive history of basalts in the eastern SRP. © 2013 Geological Society of America. 2013 English 1553040X 10.1130/GES00914.1 Geosphere 9 1319-1335 Department of Geology, Northern Illinois University, Davis Hall 312, DeKalb, Illinois 60115, United States; Institutfur Mineralogie, Leibniz Universitaet Hannover, Callinstr. 3, 30167 Hannover, Germany; Department of Geology, Utah State University, 4505 Old Main Hill, Logan, Utah 84322-4505, United States; U.S. Geological Survey, 345 Middlefield Road, Menlo Park, California 94025, United States; Department of Geology, Centenary College, Shreveport, Louisiana 71134, United States 5 aquifer; basalt; concentration (composition); fractional crystallization; igneous geochemistry; igneous intrusion; lava flow; magma; ocean island basalt; paleomagnetism; petrogenesis; tholeiite; trace element; volcanism, Idaho; Snake River Plain; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-84885087820&doi=10.1130%2fGES00914.1&partnerID=40&md5=7c7a1e8aa211bd128655576c085b5db6 cited By 7 M.M. Jean J.W. Shervais D.E. Champion S.K. Vetter article Konstantinou20131681 The Jim Sage volcanic suite (JSVS) exposed in the Jim Sage and Cotterel Mountains of southern Idaho (USA) consists of two volcanic members composed of ~240 km3 of Miocene rhyolite lavas separated by an interval of lacustrine sediments. It is capped by rheomorphic ignimbrite and as much as 100 m of basaltic lava fl ows probably derived from the central Snake River Plain (SRP) province to the north. The occurrence of volcanic vents in the JSVS links the lava fl ows to their local eruptive centers, while the adjacent Albion-Raft River-Grouse Creek metamorphic core complex exposes ~3000 km2 of once deep-seated rocks that offer constraints on the composition of the potential crustal sources of these rhyolites. U-Pb zircon ages from the rhyolite lavas of the JSVS range from 9.5 to 8.2 Ma. The Miocene basalt of the Cotterel Mountains has an 87Sr/86Sri composition of 0.7066-0.7075 and εNd(i) = -3.7, and the rhyolite lavas of the JSVS have 87Sr/86Sri = 0.7114-0.7135 and εNd(i) values that range from -6.7 to -7.1. Zircon from the rhyolites of the JSVS range in δ18Ozr (Vienna standard mean ocean water, VSMOW) from -0.5‰ to 5.7‰ and have εHf(i) values ranging from -0.8 to -6.8. Based on geochronology, whole-rock major elements, trace elements, isotopes (Sr and Nd), and in situ zircon O and Hf isotopic compositions, we infer that the JSVS is genetically related to the central SRP province. The eruption of the low-δ18O rhyolites of the JSVS, outside of the main topographic extent of the SRP province (without the large calderas inferred for the SRP rhyolites) implies that there might be an alternative mechanism for the formation of the low-δ18O signature other than the proposed assimilation of hydrothermally altered caldera blocks. One suggestion is that the north to south propagation of SRP-type low-δ18O rhyolitic melt along the Albion fault led to off-axis magmatism. Another possibility is that there was prior and widespread (across a region wider than the SRP) hydrothermal alteration of the crust related to its earlier magmatic and faulting history. The eruption of SRP-type lavas in the hanging wall of an evolving metamorphic core complex helps us outline the role of the SRP magmatic province in the extensional evolution of the northeastern Basin and Range. The lavas of the JSVS imply the addition of basalt, related to the SRP hotspot, to the crust beneath the Raft River Basin that provided a heat source for crustal melting and weakening of the deep crust; this led to a vertical component of crustal fl ow and doming during extension, after the eruption of the 9.5-8.2 Ma JSVS rhyolites. This younger than 8.2 Ma component of vertical motion during faulting of the Miocene stratifi ed sequence of the Raft River Basin and the rotation of the Albion fault to shallower angles collectively resulted in the subhorizontal detachment structure imaged seismically beneath the Raft River Basin. © 2013 Geological Society of America. 2013 English 1553040X 10.1130/GES00948.1 Geosphere 9 1681-1703 Department of Geological and Environmental Sciences, Stanford University, Stanford, CA 94305, United States; Department of Geoscience, University of Wisconsin, 1215 W. Dayton Street, Madison, WI 53706, United States; School of the Environment, Washington State University, WA 99164-2812, United States; U.S. Geological Survey, Menlo Park, CA 94025, United States 6 Hydrothermal alterations; Isotopic composition; Lacustrine sediments; Metamorphic core complex; Off-axis magmatism; Snake river plains; Standard mean ocean waters; Vertical component, Basalt; Faulting; Geochronology; Hafnium; Isotopes; Lead; Neodymium; Rivers; Strontium; Volcanoes; Watersheds; Zircon, Granite, basalt; basin evolution; caldera; detachment fault; faulting; geochronology; hafnium; hydrothermal alteration; igneous geochemistry; ignimbrite; isotopic composition; lacustrine deposit; lava flow; magmatism; Miocene; oxygen isotope; range expansion; rhyolite; uranium-lead dating; volcanic eruption; zircon, Idaho; Raft River; Snake River Plain; United States, Tetraonidae https://www.scopus.com/inward/record.uri?eid=2-s2.0-84889670967&doi=10.1130%2fGES00948.1&partnerID=40&md5=ebb1b1f756a6062f2d8b778b55fcf7c9 cited By 15 A. Konstantinou J. Valley A. Strickland E.L. Miller C. Fisher J. Vervoort J. Wooden article Morgavi2013119 Magma mixing may operate at any stage in the evolution of a magmatic system. The development of mixing is strongly controlled by fluid dynamics and its understanding requires a comprehensive physico-chemical approach in order to identify and interpret its occurrence in nature. Here, we experimentally study the physical and chemical interplays during the mixing of basaltic and rhyolitic natural melts from the Snake River Plains, USA. In particular, we present the results of the first high-temperature mixing experiments performed under controlled chaotic dynamic conditions, providing a new methodological approach to constrain the complexities of the mixing process between natural silicate melts.The mixing process is initially governed by the dynamics of stretching and folding of the melts, producing alternating flow bands. These bands increase the contact area between the end-members, which subsequently enhance chemical exchanges and thus contribute to the generation of regions with variable degrees of hybridization. We quantified the mobility of major and trace elements across contact areas, and analyzed the concentration variance decay induced by chemical diffusion. The analysis shows that elements diffuse with different efficiencies as the chemical gradient evolves and therefore, the achievement of hybrid compositions contrasts between elements. The approach introduced in this study can, in principle, be applied to mixing trends observed in nature in order to estimate the time-scales and degree of magma mixing evidenced across volcanic rocks/deposits. © 2012 Elsevier B.V. 2013 English 00092541 10.1016/j.chemgeo.2012.10.003 Chemical Geology 346 119-212 Department of Earth and Environmental Sciences, Ludwig-Maximilian-University, Theresienstrasse 41, 80333 Munich, Germany; Department Earth Sciences, University of Perugia, Piazza Universitá, 06100 Perugia, Italy; Department Geology and Geophysics, University of Liverpool, Liverpool, United Kingdom; U.S. Geological Survey, 973 Federal Center, Denver, CO 80225-0046, United States Chemical diffusion; Chemical gradients; Element mobility; Hybrid melts; Major and trace elements; Methodological approach; Mixing experiments; Snake river plains, Chemical analysis; Diffusion in solids; Experiments; Silicates, Mixing, basalt; concentration (composition); diffusion; experimental study; fluid dynamics; mixing; mobility; physicochemical property; rhyolite; silicate melt, Idaho; Snake River Plain; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-84876956502&doi=10.1016%2fj.chemgeo.2012.10.003&partnerID=40&md5=663d4a14f76585bb4f1f0ea50ca55d9a cited By 38 D. Morgavi D. Perugini C.P. De Campos W. Ertl-Ingrisch Y. Lavallée L. Morgan D.B. Dingwell article Morgavi201387 In this work we present the results of time series experiments performed by mixing basaltic and rhyolitic melts at high temperature using a device recently developed to trigger chaotic dynamics in a mixing system. The morphology of mixing patterns is quantified at different times by measuring their fractal dimension and a linear relationship is derived between mixing time and morphological complexity. The complexity of mixing patterns is also compared to the degree of homogenization of chemical elements during mixing and empirical relationships are established between the fractal dimension and the temporal variation of concentration variance of elements.New concepts and tools to study the magma mixing process unfold from the experimental results presented in this work. The first one is that the mixing patterns are fractals and they can be quantified by measuring their fractal dimension. This represents a further step in the quantification of the magma mixing process. The second outcome is that the relationship between the fractal dimension of the mixing patterns and mixing time is linear. This has important volcanological implications as the analyses of the morphology of mixing patterns in volcanic rocks can be complemented by experiments to build a new chronometer to estimate the mixing-to-eruption time. A further result from this work is the relationship between the fractal dimension of mixing patterns and concentration variance of chemical elements. This represents the first morphochemical study in igneous petrology bringing with it the potential to infer the relative mobility of chemical elements during the time progression of mixing by analyzing the morphology of mixing patterns in the rocks. © 2012. 2013 English 03770273 10.1016/j.jvolgeores.2012.12.007 Journal of Volcanology and Geothermal Research 253 87-96 Dept. Earth and Environmental Sciences, Ludwig-Maximilian-University (LMU), Theresienstrasse 41/III, 80333 München, Germany; Dept. Earth Sciences, University of Perugia, Piazza Universitá, 06100 Perugia, Italy Basaltic melts; Chaotic dynamics; Empirical relationships; High temperature; Linear relationships; Magma mixing; Mixing system; Mixing time; Morphological complexity; Relative mobility; Rhyolitic; Rhyolitic melts; Temporal variation; Time-series experiments, Chemical elements; Experiments; Fractal dimension; Fractals; Igneous rocks; Morphology; Petrography, Mixing, basalt; concentration (composition); element mobility; experimental study; high temperature; igneous geochemistry; magma chemistry; mixing ratio; morphometry; rhyolite; temporal variation; volcanology https://www.scopus.com/inward/record.uri?eid=2-s2.0-84872468459&doi=10.1016%2fj.jvolgeores.2012.12.007&partnerID=40&md5=de3cd11af88b4891c6d0e8f7c49c78e6 cited By 17 D. Morgavi D. Perugini C.P. De Campos W. Ertel-Ingrisch D.B. Dingwell article Perugini20138 The ability of chemical elements to diffuse in silicate melts is central to igneous processes. It controls the rates of phase transitions such as crystal growth and dissolution kinetics, the rate of homogenization of compositional gradients generated by fractional crystallization and assimilation of country rocks as well as one of the most intriguing processes of all, magma mixing.A very useful measure, commonly used to quantify the rate of homogenization of chemical elements in silicate melts, is the diffusion coefficient. It is widely approximated to be of a constant value (at a fixed pressure and temperature) for a melt with a given composition and rheology. When dealing with magma mixing processes, melts with different initial compositions and rheological properties (e.g. basalt and rhyolite) coexist in the same system. Under such circumstances, the compositional and rheological dependence of diffusion coefficients must be considered, leading to a considerable increase of complexity in the modeling of magma mixing. Yet, an additional and even more dramatic increase in complexity is due to the fact that the mixing of magmas is undoubtedly a very dynamic process. Scale-invariant distributions of filaments of different melts are generated by stretching and folding dynamics. This has a dual effect on the mobility of chemical elements. On the one hand their mobility increases because of an exponential increase of contact area. On the other hand, mobility can be buffered by the different diffusivities in the melts (larger in the low-viscosity than in the high-viscosity melt). Uphill diffusion of chemical elements is likely to develop at the interface between interacting magmas, further increasing the complexity of the process.Here we aim to understand chemical element mobility during melt homogenization in a magma mixing event under dynamic conditions. We have performed experiments by mixing phonolitic and alkali-basaltic melts. The mixing process was induced using a high-temperature centrifuge apparatus. The rotating speed and acceleration during all experiments were 1850. rpm and 1000. g, respectively. Experiments were performed for 5, 20 and 120. min. Samples were arranged in a buoyantly unstable geometry, with the denser material placed at the inner side of the rotating circle, resulting in injection of the mafic melt into the felsic melt during rotation. The temperature during experimental runs was 1200 (± 1)°C.From the resultant glasses, vortex-like structures generated by repeated stretching and folding dynamics were observed at the interface between the two melts. The concentrations of major and trace elements were then measured along interfaces by electron microprobe and LA-ICP-MS. The mobility of each element was next quantified by calculating the decrease (or relaxation) of concentration variance with time. The first notable result is that for major and trace elements, concentrations variance decays exponentially. The exponent of the exponential function is then chosen as a measure of element mobility. Our results show clearly that different chemical elements homogenize in the melt at differing rates. Amongst the major elements Na is the fastest element followed by Al, Mg, Ca, K and Si. The trace elements, Ba, Rb, Sr, Nb and Zr exhibit similar mobilities. The REE display the lowest mobility and they show a systematic decrease from light to heavy.The results from this study indicate that the decay of concentration variance is a robust tool for obtaining new insights into chemical exchanges during the mixing of silicate melts. Concentration variance includes in a single measure an expression of the influence of all possible factors (e.g. viscosity, composition, fluid-dynamic regime) controlling the mobility of chemical elements during the mixing of two liquids. A new parameter, the Relaxation of Concentration Variance (RCV), is proposed as an effective tool for quantifying the homogenization of chemical elements during the mixing of silicate melts. © 2012 Elsevier B.V. 2013 English 00092541 10.1016/j.chemgeo.2012.10.050 Chemical Geology 335 8-23 Department of Earth Sciences, University of Perugia, Italy; Department of Earth and Environmental Sciences, Ludwig-Maximilian-University, Germany Centrifuge experiments; Chemical exchange; Compositional gradients; Contact areas; Crystal growth and dissolution; Dual effect; Dynamic condition; Dynamic process; Effective tool; Electron microprobes; Element mobility; Exponential increase; Folding dynamics; Fractional crystallization; High temperature; High viscosities; Initial composition; La-ICP-MS; Magma mixing; Major and trace elements; Major elements; Mixing process; Natural melts; New parameters; Pressure and temperature; Rheological property; Rotating speed; Scale-invariant; Silicate melts; Up-hill diffusion, Barium; Centrifuges; Chemical elements; Crystal growth; Diffusion; Dynamics; Experiments; Mixing; Niobium; Rheology; Rubidium; Silicates; Sodium; Spectrometry; Viscosity; Zirconium, Process control, alkali basalt; centrifugal model test; concentration (composition); country rock; dissolution; element mobility; experimental study; fractional crystallization; igneous geochemistry; magma; P-T conditions; reaction kinetics; rheology; silicate melt; trace element https://www.scopus.com/inward/record.uri?eid=2-s2.0-84869871626&doi=10.1016%2fj.chemgeo.2012.10.050&partnerID=40&md5=5148ad116957e853ec311a2b572f31f7 cited By 28 D. Perugini C.P. De Campos D.B. Dingwell A. Dorfman article Morgavi2013615 We present the first set of chaotic mixing experiments performed using natural basaltic and rhyolitic melts. The mixing process is triggered by a recently developed apparatus that generates chaotic streamlines in the melts, mimicking the development of magma mixing in nature. The study of the interplay of physical dynamics and chemical exchanges between melts is carried out performing time series mixing experiments under controlled chaotic dynamic conditions. The variation of major and trace elements is studied in detail by electron microprobe and Laser Ablation ICP-MS. The mobility of each element during mixing is estimated by calculating the decrease in the concentration variance in time. Both major and trace element variances decay exponentially, with the value of exponent of the exponential function quantifying the element mobility. Our results confirm and quantify how different chemical elements homogenize in the melt at differing rates. The differential mobility of elements in the mixing system is considered to be responsible for the highly variable degree of correlation (linear, nonlinear, or scattered) of chemical elements in many published inter-elemental plots. Elements with similar mobility tend to be linearly correlated, whereas, as the difference in mobility increases, the plots become progressively more nonlinear and/or scattered. The results from this study indicate that the decay of concentration variance is in fact a robust tool for obtaining new insights into chemical exchanges during mixing of silicate melts. Concentration variance is (in a single measure) an expression of the influence of all possible factors (e.g., viscosity, composition, and fluid dynamic regime) controlling the mobility of chemical elements and thus can be an additional petrologic tool to address the great complexity characterizing magma mixing processes. © 2013 Springer-Verlag Berlin Heidelberg. 2013 English 00107999 10.1007/s00410-013-0894-1 Contributions to Mineralogy and Petrology 166 615-638 Department of Earth and Environmental Sciences, Ludwig-Maximilian-University (LMU), Theresienstrasse 41/III, 80333 Munich, Germany; Department of Earth Sciences, University of Perugia, Piazza Universitá, 06100 Perugia, Italy 2 chaotic dynamics; concentration (composition); element mobility; experimental study; magma chemistry; mixing; rhyolite; tectonic evolution; tectonic setting; time series analysis https://www.scopus.com/inward/record.uri?eid=2-s2.0-84880638818&doi=10.1007%2fs00410-013-0894-1&partnerID=40&md5=a4d1c0154874ef8e89844585677fcfde cited By 37 D. Morgavi D. Perugini C.P. Campos W. Ertel-Ingrisch D.B. Dingwell article Perugini2012326 We present new experimental results on the study of the space and time modulation of compositional fields during chaotic mixing between mafic and felsic silicate melts. The experimental strategy was planned using numerical simulations performed using the experimental geometry. These mixing experiments were performed using a recently developed experimental apparatus, which is capable of mixing high-viscosity silicate melts at high temperatures and under precisely controlled conditions of fluid-dynamics and strain. The compositional variability produced by the mixing process was investigated both along linear analytical transects and on high-resolution 2D X-ray maps, covering the mixing patterns.Our results indicate that chaotic flow fields represent very powerful dynamics to blend silicate melts, even under laminar fluid dynamic conditions (Reynolds number ca. 10-7) and for dissimilar melts with high viscosity ratios (on the order of 103). The repetition of stretching and folding processes between the two melts induced a strong increase of contact interfaces thus favoring efficient chemical exchanges. As a result the initial mafic composition is no longer detectable in the mixing system after ca. 2h (i.e. the duration of the experiment). A further important result is the observation of highly non-linear patterns in inter-elemental plots produced by the onset of diffusive fractionation processes. This is contrary to common thinking that magma mixing should always produce linear trends between pairs of chemical elements.A new measure, the "concentration variance", is proposed to quantify chemical element mobility during the mixing process. This measure is statistically robust and can be quantitatively used to measure chemical element mobility independently of the geometry in which the compositional variation (i.e. transects, areas, etc.) is embedded or the local strain history of the mingling.Our results highlight concentration variance as a robust probe of the as yet poorly-understood processes involved in the common petrological process of magma mixing. © 2012 Elsevier B.V. 2012 English 00244937 10.1016/j.lithos.2012.09.010 Lithos 155 326-340 Department of Earth Sciences, University of Perugia, Italy; Department of Earth and Environmental Sciences, Ludwig-Maximilian-University, Germany computer simulation; experimental study; felsic rock; fluid dynamics; fractionation; high temperature; igneous intrusion; laminar flow; mafic rock; mixing; petrology; Reynolds number; silicate melt https://www.scopus.com/inward/record.uri?eid=2-s2.0-84869875621&doi=10.1016%2fj.lithos.2012.09.010&partnerID=40&md5=8aeb369f940fa82ebfc8d89444f5827b cited By 34 D. Perugini C.P. De Campos W. Ertel-Ingrisch D.B. Dingwell article Schmitt20121017 Hotspot: The Snake River Geothermal Drilling Project was undertaken to better understand the geothermal systems in three locations across the Snake River Plain with varying geological and hydrological structure. An extensive series of standard and specialized geophysical logs were obtained in each of the wells. Hydrogen-index neutron and γ-γ density logs employing active sources were deployed through the drill string, and although not fully calibrated for such a situation do provide semi-quantitative information related to the 'stratigraphy' of the basalt flows and on the existence of alteration minerals. Electrical resistivity logs highlight the existence of some fracture and mineralized zones. Magnetic susceptibility together with the vector magnetic field measurements display substantial variations that, in combination with laboratory measurements, may provide a tool for tracking magnetic field reversals along the borehole. Full waveform sonic logs highlight the variations in compressional and shear velocity along the borehole. These, together with the high resolution borehole seismic measurements display changes with depth that are not yet understood. The borehole seismic measurements indicate that seismic arrivals are obtained at depth in the formations and that strong seismic reflections are produced at lithological contacts seen in the corresponding core logging. Finally, oriented ultrasonic borehole televiewer images were obtained over most of the wells and these correlate well with the nearly 6 km of core obtained. This good image log to core correlations, particularly with regards to drilling induced breakouts and tensile borehole and core fractures will allow for confident estimates of stress directions and or placing constraints on stress magnitudes. Such correlations will be used to orient in core orientation giving information useful in hydrological assessments, paleomagnetic dating, and structural volcanology. 2012 English 9781622764341 01935933 Transactions - Geothermal Resources Council 36 2 1017-1022 Institute for Geophysical Research, Dept. of Physics, University of Alberta, Edmonton, AB, Canada; Center for Geophysical Investigation of the Shallow Subsurface, Boise State University, Boise, ID, United States; Department of Geology, Utah State University, Logan, UT, United States; ICDP Operational Support Group, Deutsches GeoForschungZentrum GFZ, Potsdam, Germany; United States Geological Survey, Menlo Park, CA, United States Electrical resistivity; Geophysical logging; Hydrological assessment; Laboratory measurements; Magnetic field reversal; Snake river plains; Substantial variations; Vertical seismic profiles, Electric conductivity; Electric logging; Fracture; Geothermal fields; Geothermal wells; Landforms; Lithology; Magnetic susceptibility; Radioactivity logging; Rivers; Seismology; Stratigraphy; Stresses; Structural geology, Boreholes https://www.scopus.com/inward/record.uri?eid=2-s2.0-84876249897&partnerID=40&md5=ae01f8c1773fa469b24c606824e1f013 cited By 7 L.M. Liberty J.E. Kessler R. Kofman R. Bishop J.W. Shervais J.P. Evans D.E. Champion article Shervais2012767 The Snake River volcanic province (SRP) overlies a thermal anomaly that extends deep into the mantle; it represents one of the highest heat flow provinces in North America. The primary goal of this project is to evaluate geothermal potential in three distinct settings: (1) Kimama site: inferred high sub-aquifer geothermal gradient associated with the intrusion of mafic magmas, (2) Kimberly site: a valley-margin setting where surface heat flow may be driven by the up-flow of hot fluids along buried caldera ring-fault complexes, and (3) Mountain Home site: a more traditional fault-bounded basin with thick sedimentary cover. The Kimama hole, on the axial volcanic zone, penetrated 1912 m of basalt with minor intercalated sediment; no rhyolite basement was encountered. Temperatures are isothermal through the aquifer (to 960 m), then rise steeply on a super-conductive gradient to an estimated bottom hole temperature of ∼98°C. The Kimberly hole is on the inferred margin of a buried rhyolite eruptive center, penetrated rhyolite with intercalated basalt and sediment to a TD of 1958 m. Temperatures are isothermal at 55-60°C below 400 m, suggesting an immense passive geothermal resource. The Mountain Home hole is located above the margin of a buried gravity high in the western SRP. It penetrates a thick section of basalt and lacustrine sediment overlying altered basalt flows, hyaloclastites, and volcanic sediments, with a TD of 1821 m. Artesian flow of geothermal water from 1745 m depth documents a power-grade resource that is now being explored in more detail. In-depth studies continue at all three sites, complemented by high-resolution gravity, magnetic, and seismic surveys, and by downhole geophysical logging. Conference paper 2012 English 978-162276434-1 01935933 Transactions - Geothermal Resources Council 36 2 767 – 772 Department of Geology, Utah State University, Logan, UT, United States; DOSECC, Inc., Salt Lake City, UT, United States; Department of Geological Sciences, Brigham Young University, Provo, UT, United States; US Geological Survey, Denver, CO, United States; Department of Physics, University of Alberta, Edmonton, AB, Canada; Center for Geophysical Investigation of the Shallow Subsurface, Boise State University, Boise, ID, United States; Roy Huffington Dept. of Earth Sciences, Southern Methodist University, Dallas, TX, United States; US Geological Survey, Menlo Park, CA, United States Aquifers; Basalt; Geothermal fields; Geothermal wells; Granite; Isotherms; Natural resources exploration; Rivers; Sedimentology; Volcanoes; Bottom hole temperatures; Downhole geophysical logging; Geothermal resources; Hot spot; Idaho; Lacustrine sediments; Rhyolite; Snake river plains; Sediments https://www.scopus.com/inward/record.uri?eid=2-s2.0-84876233464&partnerID=40&md5=c4e66fa8a0f5f878b9f4ba46fe518258 Cited by: 14 John W. Shervais Dennis Nielson James P. Evans Thomas Lachmar Eric H. Christiansen Lisa Morgan W. C. Pat Shanks Christopher Delahunty Lee M. Liberty David D. Blackwell Jonathan M. Glen James A. Kessler Katherine E. Potter Marlon M. Jean Christopher J. Sant Thomas G. Freeman article Almeev20121837 The phase relations have been investigated experimentally at 200 and 500 MPa as a function of water activity for one of the least evolved (Indian Batt Rhyolite) and of a more evolved rhyolite composition (Cougar Point Tuff XV) from the 12·8-8·1 Ma Bruneau-Jarbidge eruptive center of the Yellowstone hotspot. Particular priority was given to accurate determination of the water content of the quenched glasses using infrared spectroscopic techniques. Comparison of the composition of natural and experimentally synthesized phases confirms that high temperatures (&gt;900°C) and extremely low melt water contents (&lt;1·5 wt % H. 2O) are required to reproduce the natural mineral assemblages. In melts containing ∼0·5-1·5 wt % H. 2O, the liquidus phase is clinopyroxene (excluding Fe-Ti oxides, which are strongly dependent on fO. 2), and the liquidus temperature of the more evolved Cougar Point Tuff sample (BJR; ∼940-1000°C) is at least 30°C lower than that of the Indian Batt Rhyolite lava sample (IBR2; 970-1030°C). For the composition BJR, the comparison of the compositions of the natural and experimental glasses indicates a pre-eruptive temperature of at least 900°C. The composition of clinopyroxene and pigeonite pairs can be reproduced only for water contents below 1·5 wt % H. 2O at 900°C, or lower water contents if the temperature is higher. For the composition IBR2, a minimum temperature of 920°C is necessary to reproduce the main phases at 200 and 500 MPa. At 200 MPa, the pre-eruptive water content of the melt is constrained in the range 0·7-1·3 wt % at 950°C and 0·3-1·0 wt % at 1000°C. At 500 MPa, the pre-eruptive temperatures are slightly higher (by ∼30-50°C) for the same ranges of water concentration. The experimental results are used to explore possible proxies to constrain the depth of magma storage. The crystallization sequence of tectosilicates is strongly dependent on pressure between 200 and 500 MPa. In addition, the normative Qtz-Ab-Or contents of glasses quenched from melts coexisting with quartz, sanidine and plagioclase depend on pressure and melt water content, assuming that the normative Qtz and Ab/Or content of such melts is mainly dependent on pressure and water activity, respectively. The combination of results from the phase equilibria and from the composition of glasses indicates that the depth of magma storage for the IBR2 and BJR compositions may be in the range 300-400 MPa (∼≤13 km) and 200-300 MPa (∼≤10 km), respectively. © The Author 2012. Published by Oxford University Press. All rights reserved. 2012 English 00223530 10.1093/petrology/egs035 Journal of Petrology 53 1837-1866 Institute of Mineralogy, Leibniz University of Hannover, Callinstraße 3, 30167 Hannover, Germany; Department of Geology and Geophysics, University of Utah, Salt Lake City, UT 84112-011, United States 9 concentration (composition); crystallization; experimental study; high temperature; hot spot; lava; magma; phase equilibrium; rhyolite; tectosilicate; volcanic eruption; water content, Idaho; Snake River Plain; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-84865577284&doi=10.1093%2fpetrology%2fegs035&partnerID=40&md5=495cd1ba7506bb8631c3b28537f07b69 cited By 56 R.R. Almeev T. Bolte B.P. Nash F. Holtz M. Erdmann H.E. Cathey article Nielson2012727 The Hotspot project has sampled three different geothermal environments in the Snake River Plain (SRP) in Idaho. The project used slim-hole wire line coring in conjunction with a bottom hole temperature probe developed by DOSECC. The first hole at Kimama in the center of the eastern SRP was cored to a depth of 1,915 m. Temperature measurements showed the SRP fresh water aquifer extends to a depth of 965 m and masks the underlying temperature gradient of 74.5°C/Km. A core hole in the town of Kimberly reached a depth of 1,959 m and demonstrated a resource of >50°C from 800 m to the bottom of the hole. A core hole at Mountain Home AFB in the eastern SRP reached a depth of 1,821 m and documents an intermediate- to high-temperature resource. 2012 English 9781622764341 01935933 Transactions - Geothermal Resources Council 36 1 727-730 DOSECC, Salt Lake City, UT, United States; Utah State University, Logan, UT, United States Air Force Base; Bottom-hole temperatures; ID; Kimama; Kimberly; Slim-hole coring; Snake River, Aquifers; Geothermal wells; Rivers; Temperature measurement; Thermal gradients, Geothermal fields https://www.scopus.com/inward/record.uri?eid=2-s2.0-84876209584&partnerID=40&md5=1dd7f4860dcaab17e56aa3d71bdf790f cited By 13 D.L. Nielson C. Delahunty J.W. Shervais article Breckenridge2012615 The U.S. Air Force is facing a number of challenges as it moves into the future, one of the biggest being how to provide safe and secure energy to support base operations. A team of scientists and engineers met at Mountain Home Air Force Base near Boise, Idaho, to discuss the possibility of exploring for geothermal resources under the base. The team identified that there was a reasonable potential for geothermal resources based on data from an existing well. In addition, a regional gravity map helped identify several possible locations for drilling a new well. The team identified several possible sources of funding for this well - the most logical being to use U.S. Department of Energy funds to drill the upper half of the well and U.S. Air Force funds to drill the bottom half of the well. The well was designed as a slimhole well in accordance with State of Idaho Department of Water Resources rules and regulations. Drilling operations commenced at the Mountain Home site in July of 2011 and were completed in January of 2012. Temperatures increased gradually, especially below a depth of 2000 ft. Temperatures increased more rapidly below a depth of 5500 ft. The bottom of the well is at 5976 ft, where a temperature of about 140°C was recorded. The well flowed artesian from a depth below 5600 ft, until it was plugged off with drilling mud. Core samples were collected from the well and are being analyzed to help understand permeability at depth. Additional tests using a televiewer system will be run to evaluate orientation and directions at fractures, especially in the production zone. A final report on the well exploitation will be forthcoming later this year. The Air Force will use it to evaluate the geothermal resource potential for future private development options at Mountain Home AFB. 2012 English 9781622764341 01935933 Transactions - Geothermal Resources Council 36 1 615-619 Energy and Environmental Sciences Directorate, Idaho National Laboratory, Idaho Falls, ID, United States; DOSECC, Salt Lake City, UT, United States; Department of Geology, Utah State University, Logan, UT, United States Air Force Base; Deep slimhole cores; Department of Water Resources; Geothermal; Resource assessments; Rules and regulations; Scientists and engineers; U.S. Department of Energy, Drills; Geothermal fields; Landforms; Oil well drilling, Military aviation https://www.scopus.com/inward/record.uri?eid=2-s2.0-84876279676&partnerID=40&md5=0949eaa3e39c446a1710c892c1c03a5e cited By 5 R.P. Breckenridge D.L. Nielson J.W. Shervais T.R. Wood article Delahunty2012641 A deep core drilling project focused on evaluating the geothermal potential of the Snake River Plains in southern Idaho. Slim-hole continuous diamond coring and associated geophysical surveys were used to sample different geothermal environments. Three locations were drilled with target depths as follows: Kimama 1915 m, Kimberly 1959 m, and Mountain Home 1821 m. All total depths were accomplished or exceeded. A continuous core sample was produced and down-hole temperature while drilling was collected. Conference paper 2012 English 978-162276434-1 01935933 Transactions - Geothermal Resources Council 36 1 641 – 647 DOSECC, Salt Lake City, UT, United States; Utah State University, Logan, UT, United States Core drilling; Geothermal fields; Geothermal; Kimama (Idaho); Kimberly (Idaho); Mountain Home (Idaho); Slim-hole coring; Snake river plains; Wireline; Rivers https://www.scopus.com/inward/record.uri?eid=2-s2.0-84876266974&partnerID=40&md5=834e838891feea9c2b0f84755d4a21a8 Cited by: 4 Chris Delahunty Dennis L. Nielson John W. Shervais article Lachmar2012689 A geothermal test well at Mountain Home AFB in southwestern Idaho encountered artesian flow of geothermal water from a depth of 1,745 m. Samples taken from the well head after 12 hours of flow had a pH of 9.59, and an electrical conductivity of 870 μS. The high pH suggests that the water is at equilibrium with weathered basalt at the measured temperature. The water is high in sulfate relative to chloride and bicarbonate, and high in sodium relative to calcium and magnesium, but has a TDS content of only 1,120 mg/L. Pyrite is probably the source of the sulfate. Deuterium and oxygen-18 levels are -88 and -3.2 per mil, respectively, suggesting that the water is old, not meteoric, and/or has undergone significant fractionation. Calculated equilibrium temperatures vary from ∼134°C to ∼154°C. The calculated temperatures are similar to those measured in the test well. The data suggest a potential electric-grade resource. Further work is in progress. 2012 English 9781622764341 01935933 Transactions - Geothermal Resources Council 36 1 689-692 Department of Geology, Utah State University, Logan, UT, United States; Idaho National Laboratory, Idaho Falls, ID, United States; DOSECC, Inc., Salt Lake City, UT, United States Calcium and magnesiums; Electrical conductivity; Equilibrium temperatures; Geothermal water; Hot spot; Measured temperatures; Mountain Home; Snake river plains, Basalt; Chemistry; Chlorine compounds; Electric conductivity; Geothermal fields; Landforms; Sodium bicarbonate; Sodium sulfate, Geothermal wells https://www.scopus.com/inward/record.uri?eid=2-s2.0-84876257544&partnerID=40&md5=6362105e04c4dfb1138a410ececf94f6 cited By 4 T.E. Lachmar T.G. Freeman T.R. Wood J.W. Shervais D.L. Nielson article Sant2011987 Project Hotspot offers further understanding of the history and evolution of the Snake River Plain (SRP) through drilling wells in the SRP. The first well at Kimama encountered almost entirely basalt. Kimama drilled through a gradual transition from fresh to altered basalt with depth. The evolution of mineralization with depth at Kimama was initially calcite and some quartz followed by smectite clay minerals (nontronite and saponite) and zeolites. Smectite clay minerals are a great indicator of paleo-temperature of geothermal fluids. Description of the Kimama core, mineral habits, and forthcoming chemical analyses will be discussed in this paper. 2011 English 9781618394828 01935933 Transactions - Geothermal Resources Council 35 2 987-989 Utah State University, Logan, UT, United States Geothermal; Geothermometers; Hot spot; Kimama; Snake river plains, Basalt; Calcite; Carbonate minerals; Chemical analysis; Clay; Drilling; Geothermal fields; Geothermal prospecting; Mineralogy; Quartz; Rivers, Clay minerals https://www.scopus.com/inward/record.uri?eid=2-s2.0-84860874752&partnerID=40&md5=4c1375940814f3e072b0c614de546e39 cited By 3 C.J. Sant J.W. Shervais article Shervais2009141 Basaltic volcanism in the western Snake River Plain underwent an abrupt change circa ~ 700 ka to 900 ka, from low-K tholeiitic basalt and ferrobasalt to high-K transitional alkali basalt. The low-K tholeiitic basalts share major element, trace element, and isotopic characteristics with olivine tholeiites of the eastern Snake River Plain, and must have been derived by similar processes from similar sources. In contrast, the younger high-K alkali basalts share major element, trace element, and isotopic characteristics with plume-derived alkali basalts of ocean islands suites like Hawaii. We conclude that this abrupt transition reflects either or both the erosion of pre-existing mantle lithosphere in the wake of the Yellowstone-Snake River plume, or the depletion of this lithosphere in fusible components so that it no longer contributed to the overall mass flux of magma. The abruptness of the transition implies that it may have a catastrophic origin, such as lithospheric delamination caused by a Rayleigh-Taylor instability beneath the Idaho batholith. © 2009 Elsevier B.V. All rights reserved. 2009 English 03770273 10.1016/j.jvolgeores.2009.01.023 Journal of Volcanology and Geothermal Research 188 141-152 Department of Geology, Utah State University, Logan, UT 84322-4505, United States; Department of Geology, Centenary College, Shreveport, LA 71134, United States 1-3 Abrupt change; Abrupt transition; Alkali basalt; Alkaline plumes; Basaltic volcanism; Hotspots; Idaho Batholith; Isotopic characteristics; Lithospheric; Major elements; Mantle lithosphere; Mass flux; Rayleigh-Taylor instabilities; Snake River; Snake river plains; SRP; Tholeiitic basalts; Yellowstone plume; Yellowstones, Isotopes; Oceanography; Olivine; Rivers; Sedimentary rocks; Silicate minerals; Trace elements, Basalt, alkali basalt; alkaline rock; hot spot; mantle plume; ocean island basalt; tholeiite; trace element; volcanism, Idaho; North America; Snake River Plain; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-71749107576&doi=10.1016%2fj.jvolgeores.2009.01.023&partnerID=40&md5=3f84660d1f74e44ff589eb6d8e4f3a3e cited By 14 J.W. Shervais S.K. Vetter article Shervais2008 The trace of the Snake River-Yellowstone hot spot is the world's best example of a mantle plume that has been overridden by continental lithosphere. The "standard model" calls for the plume head to rise under northern Nevada and be forced northward to form basalts of the Columbia Plateau; subsequent movement of North America to the southwest over the plume tail created a hot spot trace on the surface. We present a new conceptual model for the origin of this feature that resolves inconsistencies in the current standard model and explains the recent documentation of a thermal anomaly in the mantle below Yellowstone today that plunges ∼ 65° WNW. Our model implies that the plume tail was forced beneath thinned cratonic lithosphere to the SE along with part of the plume head and has remained in this orientation for the last 12 Ma. We infer that almost all of the voicanism in SE Oregon and SW Idaho prior to 12 Ma results from overriding the southern extension of the plume head, not the plume tail, and that a distinct plume tail hot spot track was not established until formation of the Bruneau-Jarbidge eruptive center around 12 Ma. The plume tail track may also be controlled by a preexisting structural boundary in lithosphere that is thinner than adjacent lithosphere. This model demonstrates the potential importance of lithospheric topography on controlling the surface manifestation of plume volcanism and the complexity that may arise when lithospheric thickness is nonuniform. Copyright 2008 by the American Geophysical Union. 2008 English 02787407 10.1029/2007TC002181 Tectonics 27 Department of Geology, Utah State University, Logan, UT 84322-4505, United States; Department of Geological Sciences, San Diego State University, San Diego, CA 92182-1020, United States 5 basalt; continental lithosphere; craton; extensional tectonics; hot spot; mantle plume; structural control; topography; volcanic eruption; volcanism, Idaho; Nevada; North America; Oregon; Snake River; United States; Yellowstone River https://www.scopus.com/inward/record.uri?eid=2-s2.0-58149519348&doi=10.1029%2f2007TC002181&partnerID=40&md5=201d139369a6d75a0c81816e7317fa51 cited By 67 J.W. Shervais B.B. Hanan article Botcharnikov20081687 Crystallization experiments using a hydrous ferrobasalt as starting material, conducted at 200 MPa, 940-1200°C, at a wide range of water activities (0.1-1) and redox conditions (QFM - 3 to QFM + 4, where QFM is the quartz-fayalite-magnetite oxygen buffer), show that H2O influences significantly the differentiation history of ferrobasaltic magmas. A combination of our data with published experiments on dry ferrobasalt at 1 atm provides an extensive experimental database for modeling and quantifying crystallization and differentiation processes within a typical Fe-rich tholeiitic system under both dry and hydrous conditions. The addition of H2O decreases liquidus temperatures and changes significantly the proportions, temperature range and sequence of crystallizing mineral phases. The dry liquidus is at about 1170°C whereas the liquidus for H2O-saturated melts is at ∼1060°C. The main phases crystallizing from H2O-bearing ferrobasalt at the investigated conditions are olivine (OL), clinopyroxene (CPX), plagioclase (PL), magnetite (MT), hematite (HM), ilmenite (ILM) and amphibole (AM). The phase assemblage is similar to that of the dry system except for the presence of HM at extremely oxidizing conditions and AM at low temperatures (&lt; 950°C) and H2O-saturated conditions. The important observation made in this study is that the stability of Fe-Ti-oxides, and in particular MT, as well as the simultaneous coprecipitation of MT and ILM, are almost independent of the activity of H2O (a H2O) in the system, whereas the liquidus temperatures of the silicate minerals are dramatically depressed by increasing a H2O. The stabilities of oxides are controlled mainly by the redox conditions prevailing in the system. The most pronounced effect of a H2O on the liquidus temperatures of silicates is observed for PL, which shows a considerable delay in crystallization with progressive magma differentiation. Early crystallization of Fe-Ti-oxides in H2O-bearing ferrobasaltic compositions precludes any significant Fe enrichment during differentiation. As Fe enrichment is a characteristic feature of the Skaergaard intrusion, it implies that the Skaergaard parental magma did not contain considerable amounts of water. On the other hand, our experiments indicate that the differentiation of some ferrobasaltic series from the Columbia River flood basalt province might have occurred in magmatic systems containing significant amounts of volatiles (∼0.5-3 wt % H2O). © The Author 2008. Published by Oxford University Press. All rights reserved. 2008 English 00223530 10.1093/petrology/egn043 Journal of Petrology 49 1687-1727 Institut für Mineralogie, Leibniz Universität Hannover, Callinstr. 3, D-30167 Hannover, Germany 9 crystallization; differentiation; experimental study; flood basalt; hydrothermal system; magma; modeling; precipitation (chemistry); redox conditions; silicate mineral, Arctic; Columbia River; Greenland; North America; Skaergaard Intrusion https://www.scopus.com/inward/record.uri?eid=2-s2.0-53349116865&doi=10.1093%2fpetrology%2fegn043&partnerID=40&md5=ec7e9202baa46bea20e9b83bfe2aaced cited By 152 R.E. Botcharnikov R.R. Almeev J. Koepke F. Holtz article Hanan200851 The Snake River Plain represents 17 m.y. of volcanic activity that took place as the North American continent migrated over a relatively fixed magma source, or hotspot. The identification of a clear seismic image of a plume beneath Yellowstone is compelling evidence that the Miocene to recent volcanism associated with the Columbia Plateau, Oregon High Lava Plains, Snake River Plain, Northern Nevada Rift and Yellowstone Plateau represents a single magmatic system related to a mantle plume. A remaining enigma is, why do radiogenic isotope signatures from basalts erupted over the Mesozoic-Paleozoic accreted terrains suggest a plume source while basalts erupted across the Proterozoic-Archean craton margin indicate an ancient subcontinental mantle lithosphere source? We show that ancient cratonic lithosphere like that of the Wyoming province superimposes its inherent isotopic composition on sublithospheric plume and/or asthenospheric melts. The results show that Yellowstone plume could have a radiogenic isotope composition similar to the mantle source of the early Columbia River Basalt Group and that the plume source composition has persisted to the present day. © 2008 The Geological Society of America. 2008 English 00917613 10.1130/G23935A.1 Geology 36 51-54 Department of Geological Sciences, San Diego State University, San Diego, CA 92182-1020, United States; Department of Geology, Utah State University, Logan, UT 84322-4505, United States; Department of Geology, Centenary College, Shreveport, LA 71134, United States 1 Lithosphere; Mantle plume; Volcanic activity, Basalt; Geochemistry; Isotopes; Tectonics; Volcanoes, Volcanic rocks, basalt; continental lithosphere; isotopic composition; lead isotope; mantle plume; mantle source; neodymium isotope; strontium isotope, Idaho; North America; Snake River Plain; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-38349057664&doi=10.1130%2fG23935A.1&partnerID=40&md5=c6e0b389b06c512525be01941edc64d2 cited By 71 B.B. Hanan J.W. Shervais S.K. Vetter article Shervais200656 Article 2006 English 18163459 10.2204/iodp.sd.3.14.2006 Scientific Drilling 1 56 – 57 Geology Department, Utah State University, 4505 Old Main Hill, Logan, UT 84322-4505, United States; Department of Geology, University of Leicester, University Road, Leicester LE1 7RH, United Kingdom; Department of Geological Sciences, University of Idaho, Moscow, ID 83844-3022, United States; Department of Geological Science, San Diego State University, MC-1020, 5500 Campanile Drive, San Diego, CA 92182-1020, United States; Department of Geosciences, Idaho State University, Campus Box 8072, 785 South 8th Avenue, Pocatello, ID 83209-8072, United States; Department of Geological Sciences, University of South Carolina, 701 Sumter Street, Columbia, S.C. 29208, United States 3 https://www.scopus.com/inward/record.uri?eid=2-s2.0-84860848276&doi=10.2204%2fiodp.sd.3.14.2006&partnerID=40&md5=be74630da1f339c16b23d221345767ed Cited by: 12; All Open Access, Gold Open Access, Green Open Access John W. Shervais Michael J. Branney Dennis J. Geist Barry B. Hanan Scott Hughes Alexsander A. Prokopenko Douglas F. Williams article Wicks200672 The Yellowstone caldera, in the western United States, formed ∼640,000 years ago when an explosive eruption ejected ∼1,000 km3 of material. It is the youngest of a series of large calderas that formed during sequential cataclysmic eruptions that began ∼16 million years ago in eastern Oregon and northern Nevada. The Yellowstone caldera was largely buried by rhyolite lava flows during eruptions that occurred from ∼150,000 to ∼70,000 years ago. Since the last eruption, Yellowstone has remained restless, with high seismicity, continuing uplift/subsidence episodes with movements of ∼70 cm historically to several metres since the Pleistocene epoch, and intense hydrothermal activity. Here we present observations of a new mode of surface deformation in Yellowstone, based on radar interferometry observations from the European Space Agency ERS-2 satellite. We infer that the observed pattern of uplift and subsidence results from variations in the movement of molten basalt into and out of the Yellowstone volcanic system. © 2006 Nature Publishing Group. 2006 English 00280836 10.1038/nature04507 Nature 440 Nature Publishing Group 72-75 US Geological Survey, MS 977, Menlo Park, CA 94555, United States; US Geological Survey, David A. Johnston Cascades Volcano Observatory, Bldg. 10, 1300 SE Cardinal Court, Vancouver, WA 98683, United States 7080 Earthquakes; Interferometry; Radar; Satellites, Cataclysmic eruptions; Hydrothermal activity, Volcanoes, caldera; crustal deformation; igneous intrusion; uplift, analytic method; article; interferometer; priority journal; surface property; telecommunication; thermal analysis; volcano, North America; United States; Wyoming; Yellowstone Caldera https://www.scopus.com/inward/record.uri?eid=2-s2.0-33644773463&doi=10.1038%2fnature04507&partnerID=40&md5=f5fbd6dab6a6403b0d391723bd5829a1 cited By 128 C.W. Wicks W. Thatcher D. Dzurisin J. Svarc article Shervais200527 Basaltic volcanism in the Snake River Plain of southern Idaho has long been associated with the concept of a mantle plume that was overridden by North America during the Neogene and now resides beneath the Yellowstone plateau. This concept is consistent with the time-transgressive nature of rhyolite volcanism in the plain, but the history of basaltic volcanism is more complex. In the eastern Snake River Plain, basalts erupted after the end of major silicic volcanism. The basalts typically erupt from small shield volcanoes that cover up to 680 km 2 and may form elongate flows that extend 50-60 km from the central vent. The shields coalesce to form extensive plains of basalt that mantle the entire width of the plain, with the thickest accumulations of basalt forming an axial high along the length of the plain. In contrast, basaltic volcanism in the western Snake River Plain formed in two episodes: the first (ca. 7-9 Ma) immediately following the eruption of rhyolites lavas now exposed along the margins of the plain, and the second forming in the Pleistocene (δ2 Ma), long after active volcanism ceased in the adjacent eastern Snake River Plain. Pleistocene basalts of the western Snake River Plain are intercalated with, or overlie, lacustrine sediments of Pliocene-Pleistocene Lake Idaho, which filled the western Snake River Plain graben after the end of the first episode of basaltic volcanism. The contrast in occurrence and chemistry of basalt in the eastern and western plains suggest the interpretation of volcanism in the Snake River Plain is more nuanced than simple models proposed to date. © 2005 Geological Society of America. 2005 English 10.1130/2005.fld006(02) GSA Field Guides 6 Geological Society of America 27-52 Department of Geology, Utah State University, Logan, UT 84322-4505, United States; Idaho Geological Survey, University of Idaho, Moscow, ID 83844-3014, United States; Idaho Geological Survey, Boise State University, Boise, ID 83725-1535, United States; Department of Geology, Centenary College, Shreveport, LA 71134, United States; Department of Geological Sciences, University of South Carolina, Columbia, SC 29208, United States; Department of Geological Sciences, San Diego State University, San Diego, CA 92182-1020, United States Granite; Rivers, Basalt geochemistry; Basaltic volcanism; First episodes; Lacustrine sediments; Mantle plume; Silicic volcanism; Snake river plains; Yellowstones, Basalt https://www.scopus.com/inward/record.uri?eid=2-s2.0-85065264109&doi=10.1130%2f2005.fld006%2802%29&partnerID=40&md5=a913f9d79d0f1515b6795e68f79261f0 cited By 24 J.W. Shervais J.D. Kauffman V.S. Gillerman K.L. Othberg S.K. Vetter R.V. Hobson M. Zarnetske M.F. Cooke S.H. Matthews B.B. Hanan article shervais2002origin 2002 Tectonic and Magmatic Evolution of the Snake River Plain Volcanic Province 30 Idaho Geologic Survey Bulletin Moscow, Idaho USA 343--361 John W Shervais Gaurav Shroff Scott K Vetter Scott Matthews Barry B Hanan James J McGee B Bonnichsen CM White M McCurry