This file was created by the TYPO3 extension publications --- Timezone: CEST Creation date: 2026-04-15 Creation time: 03:18:44 --- Number of references 2 article Fekiacova200765 The "Ko'olau" component of the Hawaiian mantle plume represents an extreme (EM1-type) end member of Hawaiian shield lavas in radiogenic isotope space, and was defined on the basis of the composition of subaerial lavas exposed in the Makapu'u section of Ko'olau Volcano. The 679 m-deep Ko'olau Scientific Drilling Project (KSDP) allows the long-term evolution of Ko'olau Volcano to be reconstructed and the longevity of the "Ko'olau" component in the Hawaiian plume to be tested. Here, we report triple spike Pb isotope and Sr and Nd isotope data on KSDP core samples, and rejuvenation stage Honolulu Volcanics (HV) (together spanning ∼ 2.8 m.y.), and from ∼ 110 Ma basalts from ODP Site 843, thought to be representative of the Pacific lithosphere under Hawai'i. Despite overlapping ranges in Pb isotope ratios, KSDP and HV lavas form two distinct linear arrays in 208Pb/204Pb-206Pb/204Pb isotope space. These arrays intersect at the radiogenic end indicating they share a common component. This "Kalihi" component has more radiogenic Pb, Nd, Hf, but less radiogenic Sr isotope ratios than the "Makapu'u" component. The mixing proportions of these two components in the lavas oscillated through time with a net increase in the "Makapu'u" component upsection. Thus, the "Makapu'u" enriched component is a long-lived feature of the Hawaiian plume, since it is present in the main shield-building stage KSDP lavas. We interpret the changes in mixing proportions of the Makapu'u and Kalihi components as related to changes in both the extent of melting as well as the lithology (eclogite vs. peridotite) of the material melting as the volcano moves away from the plume center. The long-term Nd isotope trend and short-term Pb isotope fluctuations seen in the KSDP record cannot be ascribed to a radial zonation of the Hawaiian plume: rather, they reflect the short length-scale heterogeneities in the Hawaiian mantle plume. Linear Pb isotope regressions through the HV, recent East Pacific Rise MORB and ODP Site 843 datasets are clearly distinct, implying that no simple genetic relationship exists between the HV and the Pacific lithosphere. This observation provides strong evidence against generation of HV as melts derived from the Pacific lithosphere, whether this be recent or old (100 Ma). The depleted component present in the HV is unlike any MORB-type mantle and most likely represents material thermally entrained by the upwelling Hawaiian plume and sampled only during the rejuvenated stage. The "Kalihi" component is predominant in the main shield building stage lavas but is also present in the rejuvenated HV. Thus this material is sampled throughout the evolution of the volcano as it moves from the center (main shield-building stage) to the periphery (rejuvenated stage) of the plume. The presence of a plume-derived material in the rejuvenated stage has significant implications for Hawaiian mantle plume melting models. © 2007 Elsevier B.V. All rights reserved. 2007 English 0012821X 10.1016/j.epsl.2007.06.005 Earth and Planetary Science Letters 261 65-83 Max-Planck-Institut für Chemie, Abteilung Geochemie, Postfach 3060, 55020 Mainz, Germany; Department of Geology and Geophysics, University of Hawai'i, Manoa, Honolulu, Hawai'i 96822, United States 1-2 Lithosphere; Mantle plumes; Radial zonation, Isotopes; Lithology; Melting; Seismology; Volcanic rocks, Volcanoes, basalt; igneous geochemistry; isotopic composition; lava; lead isotope; mantle plume; neodymium isotope; Ocean Drilling Program; strontium isotope; volcanic rock, Hawaii [United States]; Hawaiian Islands; Koolau; North America; Oahu; Pacific islands; Pacific Ocean; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-34548207227&doi=10.1016%2fj.epsl.2007.06.005&partnerID=40&md5=18a1a57295d61af4737da19663a3ac1e cited By 71 Z. Fekiacova W. Abouchami S.J.G. Galer M.O. Garcia A.W. Hofmann article Haskins2004162 The Ko'olau Scientific Drilling Project (KSDP) was initiated to determine if the distinctive geochemistry of Ko'olau lavas is a near-surface feature. This project successfully deepened a recent, ∼351 m deep, tri-cone rotary-drilled water well by coring another ∼328 m. Three Ar-Ar plateau ages of 2.8 to 2.9 Ma from the drill core section of 103 flows confirm stratigraphic interpretations that core drilling recovered the deepest and oldest subaerially erupted lavas yet sampled from this volcano. The petrography and geochemistry of the core, and cuttings from this and another new Ko'olau water well (∼433 m deep) were determined. These analyses revealed that the geochemically distinct lavas of Ko'olau form a veneer only 175-250 in thick at the drill sites, covering flows with more typical Hawaiian tholeiite compositions. The compositional change occurred near the end of shield volcanism and is not abrupt. Thus, it is probably not related to a catastrophic event such as the collapse of the northeast flank of this volcano. The distinct geochemistry of surface Ko'olau lavas cannot be explained by melting pyroxenitic or combined pyroxenitic and peridotitic sources. Additional recycled oceanic crustal components, such as plagioclase-rich cumulates and sediment, were probably involved. As the Ko'olau volcano drifted off the Hawaiian hotspot and the overall degree of melting decreased, the proportion of melts from recycled oceanic crustal material increased relative to those from mantle peridotite. © Springer-Verlag 2004. 2004 English 00107999 10.1007/s00410-003-0546-y Contributions to Mineralogy and Petrology 147 162-188 Department of Geology and Geophysics, University of Hawai'i, 1680 East-West Road, Honolulu, HI 96822, United States 2 geochemistry; lava; petrography; volcanic rock, Hawaii [United States]; North America; United States https://www.scopus.com/inward/record.uri?eid=2-s2.0-2342445383&doi=10.1007%2fs00410-003-0546-y&partnerID=40&md5=7dd285442cb4679b2b285aff913b0a99 cited By 52 E.H. Haskins M.O. Garcia