This file was created by the TYPO3 extension publications --- Timezone: CEST Creation date: 2026-05-26 Creation time: 15:12:18 --- Number of references 72 article Akamatsu2025 Article 2025 10.1016/j.lithos.2025.107946 Lithos 496-497 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85215581899&doi=10.1016%2fj.lithos.2025.107946&partnerID=40&md5=bca798aedc31cc94af168630c6a87b56 Cited by: 1; All Open Access, Hybrid Gold Open Access Y. Akamatsu T. Kuwatani R. Oyanagi article Merseburger2025 Article 2025 10.1016/j.lithos.2025.108261 Lithos 516-517 https://www.scopus.com/inward/record.uri?eid=2-s2.0-105016850910&doi=10.1016%2fj.lithos.2025.108261&partnerID=40&md5=fc74efc8fb2f072bf2b300e2857a1642 Cited by: 0 Sven Merseburger Felix Marxer Ingo Horn Dieter Garbe-Schönberg Ulrike Westernströer Sandrin T. Feig Andreas B. Kaufmann François Holtz Jürgen Koepke article Michibayashi2025 Article 2025 10.1016/j.lithos.2025.107970 Lithos 496-497 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85216491816&doi=10.1016%2fj.lithos.2025.107970&partnerID=40&md5=3aa14442fc5f6ffb7131e84e37e217e7 Cited by: 0; All Open Access, Green Open Access, Hybrid Gold Open Access Katsuyoshi Michibayashi Yuki Kakihata Itsuki Natsume Takeo Okuwaki Marguerite Godard Peter Kelemen article Yoshikawa2025 Article 2025 10.1016/j.chemgeo.2025.123072 Chemical Geology 695 https://www.scopus.com/inward/record.uri?eid=2-s2.0-105018745346&doi=10.1016%2fj.chemgeo.2025.123072&partnerID=40&md5=e0c044a16b19b3136b85bd10c838084b Cited by: 1; All Open Access, Hybrid Gold Open Access Masako Yoshikawa Tomoyuki Shibata Ryoko Senda Yumiko Harigane Muhamad Asyraf Aminuddin Tomoaki Morishita article Koepke2025 Article 2025 10.1016/j.lithos.2025.107979 Lithos 498-499 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85217153042&doi=10.1016%2fj.lithos.2025.107979&partnerID=40&md5=83ab2e4c2dfb27d1084dedb40e4ad56b Cited by: 0; All Open Access, Hybrid Gold Open Access Jürgen Koepke Sandrin T. Feig Jasper Berndt Renat R. Almeev article Kleijbeuker2025 Article 2025 10.1029/2024GC011886 Geochemistry, Geophysics, Geosystems 26 4 https://www.scopus.com/inward/record.uri?eid=2-s2.0-105003895995&doi=10.1029%2f2024GC011886&partnerID=40&md5=efc0e9b8d9a79669b1924f0119f2f827 Cited by: 0; All Open Access, Gold Open Access Laurens H. Kleijbeuker Hamed Amiri Maartje F. Hamers Alissa J. Kotowski article Matter2025 Article 2025 10.1038/s43247-025-02509-5 Communications Earth and Environment 6 1 https://www.scopus.com/inward/record.uri?eid=2-s2.0-105011705357&doi=10.1038%2fs43247-025-02509-5&partnerID=40&md5=6ca8379acc6d354f9dd11a045b1d5e90 Cited by: 1; All Open Access, Gold Open Access Juerg M. Matter Joanna Speer Christopher Day Peter B. Kelemen Amal Ibrahim Sulaiman Al Mani Ehab Tasfai Moeez Ilyas Karan Khimji Talal Hasan article Jesus2025 Article 2025 10.1016/j.lithos.2024.107913 Lithos 494-495 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85212577315&doi=10.1016%2fj.lithos.2024.107913&partnerID=40&md5=85971bd5fef2da6bbce01265f24a43b5 Cited by: 1; All Open Access, Hybrid Gold Open Access Ana P. Jesus Harald Strauss Mário A. Gonçalves Michelle Harris Diogo Silva Martin J. Whitehouse Damon A.H. Teagle article Eslami2025 Article 2025 10.1016/j.lithos.2025.108160 Lithos 512-513 https://www.scopus.com/inward/record.uri?eid=2-s2.0-105009352572&doi=10.1016%2fj.lithos.2025.108160&partnerID=40&md5=510b47cac324f523eb019e576edada36 Cited by: 0; All Open Access, Green Open Access, Hybrid Gold Open Access Alireza Eslami Benjamin Malvoisin Mayuko Fukuyama Marguerite Godard Yuji Ichiyama László Előd Aradi Katsuyoshi Michibayashi Zaicong Wang Ming Li Alessandro Cavallo article Tenuta2025 Article 2025 10.1038/s41598-025-04161-7 Scientific Reports 15 1 https://www.scopus.com/inward/record.uri?eid=2-s2.0-105009532128&doi=10.1038%2fs41598-025-04161-7&partnerID=40&md5=9abb109f6215667612997c5d8bfa7127 Cited by: 0; All Open Access, Gold Open Access, Green Open Access S. Tenuta K.A. Evans S.M. Reddy B.M. Tutolo W.D.A. Rickard D.W. Saxey article Grant2024 Here we present a method for using the spatial x–y coordinate of an image cropped from the cylindrical surface of digital 3D drill core images and demonstrate how this spatial metadata can be used to improve unsupervised machine learning performance. This approach is applicable to any data set with known spatial context, however, here it is used to classify 400 m of drillcore imagery into 12 distinct classes reflecting the dominant rock types and alteration features in the core. We modified two unsupervised learning models to incorporate spatial metadata and an average improvement of 25% was achieved over equivalent models that did not utilize metadata. Our semi-supervised workflow involves unsupervised network training followed by semi-supervised clustering where a support vector machine uses a subset of M expert labeled images to assign a pseudolabel to the entire data set. Fine-tuning of the best performing model showed an f1 (macro average) of 90%, and its classifications were used to estimate bulk fresh and altered rock abundance downhole. Validation against the same information gathered manually by experts when the core was recovered during the Oman Drilling Project revealed that our automatically generated data sets have a significant positive correlation (Pearson's r of 0.65–0.72) to the expert generated equivalent, demonstrating that valuable geological information can be generated automatically for 400 m of core with only ∼24 hr of domain expert effort. © 2024 The Authors. Earth and Space Science published by Wiley Periodicals LLC on behalf of American Geophysical Union. Article 2024 10.1029/2023EA003220 Earth and Space Science 11 John Wiley and Sons Inc 3 Oman; coordinate; data set; drilling; image analysis; machine learning; rock; satellite imagery; support vector machine https://www.scopus.com/inward/record.uri?eid=2-s2.0-85187869703&doi=10.1029%2f2023EA003220&partnerID=40&md5=ab7ef4b1f846866dfd08f48dec510521 Cited by: 1; All Open Access, Gold Open Access Lewis J. C. Grant Miquel Massot-Campos Rosalind M. Coggon Blair Thornton Francesca C. Rotondo Michelle Harris Aled D. Evans Damon A. H. Teagle article Tenuta2024 Article 2024 10.1016/j.lithos.2024.107841 Lithos 488-489 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85207665138&doi=10.1016%2fj.lithos.2024.107841&partnerID=40&md5=3e01bf0f529a95bf6bcd90d554744a20 Cited by: 1; All Open Access, Hybrid Gold Open Access Stefano Tenuta Katy A. Evans Steven M. Reddy David W. Saxey Tommaso Tacchetto Denis Fougerouse Xiao Sun article Leong2024 Article 2024 10.1016/j.lithos.2024.107828 Lithos 488-489 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85205934617&doi=10.1016%2fj.lithos.2024.107828&partnerID=40&md5=0db1de0876a160ffeb978217d610a58a Cited by: 0; All Open Access, Hybrid Gold Open Access James Andrew Leong Juan Carlos Obeso Thomas Sharp Everett Shock Peter Kelemen article Decrausaz2023171 Earth's long-term cycling of carbon is regulated from mid-ocean ridges to convergent plate boundaries by mass transfers involving mantle rocks. Here we examine the conversion of peridotite to listvenite (magnesite + quartz rock) during CO2 metasomatism along the basal thrust of the Semail Ophiolite (Fanja, Sultanate of Oman). At the outcrop scale, this transformation defines reaction zones, from serpentinized peridotites to carbonated serpentinites and listvenites. Based on a detailed petrological and chemical study, we show that carbonation progressed through three main stages involving the development of replacive textures ascribed to early stages, whilst carbonate (± quartz) veining becomes predominant in the last stage. The pervasive replacement of serpentine by magnesite is characterized by the formation of spheroids, among which two types are identified based on the composition of their core regions: Fe-core and Mg-core spheroids. Fe zoning is a type feature of matrix and vein magnesite formed during the onset carbonation (Stage 1). While Fe-rich magnesite is predicted to form at low fluid XCO2 from a poorly to moderately oxidized protolith, our study evidences that the local non-redox destabilization of Fe oxides into Fe-rich magnesite is essential to the development of Fe-core spheroids. The formation of Fe-core spheroids is followed by the pervasive (over-)growth of Mg-rich spheroids and aggregates (Stage 2) at near-equilibrium conditions in response to increasing fluid XCO2. Furthermore, the compositions of carbonates indicate that most siderophile transition elements released by the dissolution of primary minerals are locally trapped in carbonate and oxides during matrix carbonation, while elements with a chalcophile affinity are the most likely to be leached out of reaction zones. © 2023 Thierry Decrausaz et al. Article 2023 10.5194/ejm-35-171-2023 European Journal of Mineralogy 35 Copernicus Publications 171 – 187 2 Oman; Semail Ophiolite; Iron oxides; Magnesite; Quartz; Serpentine; Textures; Zoning; Chemical zoning; Convergent plate boundaries; Last stage; Mantle rocks; matrix; Mid-ocean-ridge; Quartz rocks; Reaction zones; Serpentinized peridotites; Sultanate of Oman; carbonate; iron; manganese; metasomatism; mid-ocean ridge; peridotite; quartz vein; ultramafic rock; Carbonation https://www.scopus.com/inward/record.uri?eid=2-s2.0-85151426343&doi=10.5194%2fejm-35-171-2023&partnerID=40&md5=7f83598ece0fedfe26332025aca776bf Cited by: 5; All Open Access, Gold Open Access Thierry Decrausaz Marguerite Godard Manuel D. Menzel Fleurice Parat Emilien Oliot Romain Lafay Fabrice Barou article Sohn2023 Article 2023 10.1016/j.hydroa.2023.100163 Journal of Hydrology X 21 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85173040843&doi=10.1016%2fj.hydroa.2023.100163&partnerID=40&md5=4786b0ec97f6e9c70fcf03357efe2824 Cited by: 1; All Open Access, Gold Open Access R.A. Sohn J.M. Matter article WOS:000969084500001 2023 10.1029/2023JB026677 JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH 128 4 Peter B. Kelemen Jurg M. Matter Damon A. H. Teagle Jude A. Coggon Marguerite Godard Katsuyoshi Michibayashi Eiichi Takazawa Alexis S. Templeton Ken Williams Zaher Al Sulaimani article WOS:000930327800001 2023 10.1111/jmg.12713 JOURNAL OF METAMORPHIC GEOLOGY 41 5 epidote; lower oceanic crust; olivine gabbro; Oman ophiolite; prehnite; serpentinization Toshio Nozaka Yamato Tateishi article WOS:000976645200001 2023 10.3389/fmicb.2023.1138656 FRONTIERS IN MICROBIOLOGY 14 subsurface; serpentinite; recombination; evolution; geographic isolation; parapatric speciation; dispersal limitation; competitive exclusion Mason Munro-Ehrlich Daniel B. Nothaft Elizabeth M. Fones Juerg M. Matter Alexis S. Templeton Eric S. Boyd article Akamatsu2023 Article 2023 10.1029/2022GC010792 Geochemistry, Geophysics, Geosystems 24 6 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85163692922&doi=10.1029%2f2022GC010792&partnerID=40&md5=f8272e40077da840d9e187196ee444cb Cited by: 2; All Open Access, Gold Open Access Y. Akamatsu I. Katayama K. Okazaki K. Michibayashi article Plümper2023165 Olivine is the main component of the Earth’s upper mantle, on which our tectonic plates rest. As such, olivine has been studied since the dawn of geology and is regarded as the storyteller of the Earth’s interior. Its physical and chemical properties provide insight into its creation in magmas and its voyage through the upper mantle. However, when olivine is exposed to aqueous fluids, it adopts a more rebellious, rock star–like disposition. Here, we show that the discord, or disequilibrium, between olivine, its reaction products, and fluids containing water and carbon dioxide is so significant that it has been instrumental in changing the Earth throughout the planet’s history and will continue to do so well into the future. © 2023 Mineralogical Society of America. All rights reserved. Article 2023 10.2138/gselements.19.3.165 Elements 19 Mineralogical Society of America 165 – 172 3 Carbon dioxide; Earth (planet); Olivine; Stars; Alteration; Aqueous fluids; Exposed to; Physical and chemical properties; Star-like; Tectonic plates; Upper mantle; carbon dioxide; chemical alteration; olivine; serpentine; upper mantle; Serpentine https://www.scopus.com/inward/record.uri?eid=2-s2.0-85173609187&doi=10.2138%2fgselements.19.3.165&partnerID=40&md5=3cc68f775bb654b43797d7724f0a6fca Cited by: 2; All Open Access, Green Open Access Oliver Plümper Juerg Matter article WOS:001022757300001 2023 10.1029/2022JB026130 JOURNAL OF GEOPHYSICAL RESEARCH-SOLID EARTH 128 6 electrical resistivity; elastic wave velocity; oceanic crust; crack; Oman drilling Project; IODP hole 1256D Y. Akamatsu K. Nagase N. Abe K. Okazaki K. Hatakeyama I. Katayama article Lima-Zaloumis2022 Article 2022 10.1038/s43247-022-00551-1 Communications Earth and Environment 3 1 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85139513072&doi=10.1038%2fs43247-022-00551-1&partnerID=40&md5=3363dc94720b1cc50a24362ac9692c9e Cited by: 9; All Open Access, Gold Open Access, Green Open Access Jon Lima-Zaloumis Anna Neubeck Magnus Ivarsson Maitrayee Bose Rebecca Greenberger Alexis S. Templeton Andrew D. Czaja Peter B. Kelemen Tomas Edvinsson article Fones2022 Article 2022 10.1111/1462-2920.16041 Environmental Microbiology https://www.scopus.com/inward/record.uri?eid=2-s2.0-85130352571&doi=10.1111%2f1462-2920.16041&partnerID=40&md5=74cc74bc6c69d5336b2a8539cf66a73b Cited by: 7 Elizabeth M. Fones Alexis S. Templeton David W. Mogk Eric S. Boyd article grambling2022thermal We investigate the cooling histories of peridotites and gabbros from localities that expose oceanic lithosphere formed beneath two fast seafloor spreading centers: Hess Deep as recovered from IODP Expedition 345 and ODP Leg 147, and the Oman Ophiolite as sampled by the Oman Drilling Project, ICDP Expedition 5057 (OmanDP). At these locations, relict crust-mantle transition zones are directly sampled, enabling characterization of the thermal history of the crust-mantle transition, and by inference, the depth extent of hydrothermal circulation beneath spreading centers. We measured major and trace element abundances in crustal gabbros and mantle peridotites from Hess Deep and OmanDP, and applied major and trace element-based thermometers. Geospeedometric interpretation of the temperatures suggests similar cooling histories at both locations; cooling rates ranged from 0.02 to 2.6 °C/y from peak temperatures up to 1,350°C. The rates are consistent on either side of the paleo-Moho (i.e., in the crust and mantle). Models for conductive cooling of the lower oceanic crust predict rates more than two orders of magnitude slower at the crust-mantle transition zone, while thermal models that invoke deep and efficient hydrothermal circulation throughout the entire crustal section predict rates consistent with our observations. We infer that hydrothermal cooling extended to or near the petrologic Moho beneath the East Pacific Rise and the OmanDP paleo-spreading center, consistent with the Sheeted Sills model for crustal accretion. Comparison with previously published rates recalculated using the methods we employed suggests the oceanic lower crust is cooled hydrothermally in some places and by conduction at others. © 2021. American Geophysical Union. All Rights Reserved. 2022 English 21699313 10.1029/2021JB022696 Journal of Geophysical Research: Solid Earth 127 Wiley Online Library e2021JB022696 Department of Earth and Planetary Sciences, University of Tennessee, Knoxville, TN, United States; Department of Geological Sciences, University of Texas at Austin, Austin, TX, United States; Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI, United States; Leibniz Universität Hannover, Institut für Mineralogie, Hannover, Germany; Western Colorado University, Gunnison, CO, United States; Lamont Doherty Earth Observatory, Columbia University, New York, NY, United States 1 gabbro; hydrothermal alteration; mantle source; ophiolite; seafloor spreading; temperature anomaly; thermometry; trace element, East Pacific Rise; Hess Deep; Pacific Ocean https://www.scopus.com/inward/record.uri?eid=2-s2.0-85124075477&doi=10.1029%2f2021JB022696&partnerID=40&md5=29ba2009a0cf81bb0211776533045cf9 cited By 3 Nadine L Grambling Nicholas Dygert Beau Boring Marlon M Jean Peter B Kelemen article Rospabé202275 The Oman Drilling Project (OmanDP), performed under the International Continental Scientific Drilling Program (ICDP), is an international scientific research project that undertook drilling at a range of sites in the Semail ophiolite (Oman) to collect core samples spanning the stratigraphy of the ophiolite, from the upper oceanic crust down to the basal thrust. The cores were logged to International Ocean Discovery Program (IODP) standards aboard the D/V Chikyu. During ChikyuOman2018 Leg 3 (July-August 2018), participants described cores from the crust-mantle transition (CM) sites. The main rock types recovered at these sites were gabbros, dunites and harzburgites, rocks typically forming the base of the oceanic crust and the shallow mantle beneath present-day spreading centres. In addition to the core description, selected samples were analysed by X-ray fluorescence spectrometry (XRF) for their chemical compositions, including major, minor and some trace elements. To complement these standard procedures, we developed new approaches to measure ultra-trace element concentrations using a procedure adapted from previous works to prepare fine-grained pressed powder pellets coupled with laser ablation-inductively coupled plasma mass spectrometry (LA-ICP-MS) analysis using instrumentation aboard the D/V Chikyu. First, three (ultra)mafic reference materials were investigated to test and validate our procedure (BHVO-2, BIR-1a and JP-1), and then the procedure was applied to a selection of gabbro and dunite samples from the CM cores to explore the limitations of the method in its current stage of development. The obtained results are in good agreement with preferred values for the reference materials and with subsequent solution replicate analyses of the same samples performed in shore-based laboratories following Leg 3 for the CM samples. We describe this procedure for the determination of 37 minor and (ultra-)trace elements (transition elements and Ga, Li and Large-Ion Lithophile Elements (LILE), Rare Earth Elements (REE), High-Field-Strength Elements (HFSE), U, Th, and Pb) in mafic and ultramafic rocks. The presented method has the major advantage that it allows the determination at sea of the (ultra-)trace element concentrations in a "dry", safe way, without using acid reagents. Our new approach could be extended for other elements of interest and/or be improved to be adapted to other rock materials during future ocean drilling operations aboard the D/V Chikyu and other platforms. © 2022 Mathieu Rospabé et al. 2022 English 18168957 10.5194/sd-30-75-2022 Scientific Drilling 30 Copernicus GmbH 75-99 Research Institute for Marine Geodynamics (IMG), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima, Kanagawa, Yokosuka, 237-0061, Japan; Géosciences Environnement Toulouse (GET), Observatoire Midi-Pyrénées, Université de Toulouse, CNRS, IRD, 14 avenue E. Belin, Toulouse, 31400, France; Institute of Earth Sciences, Academia Sinica, Academia Road, Nangang, Taipei, 11529, Taiwan; Department of Sciences, College of Science and Engineering, Kanazawa University, Kanazawa, Ishikawa, 920-1192, Japan; Department of Geology, Faculty of Science, Niigata University, Niigata, Niigata, 950-2181, Japan; Instituto Andaluz de Ciencias de la Tierra (IACT), Consejo Superior de Investigaciones Científicas-Universidad de Granada, Avd. Palmeras 4, Armilla, Granada, 18100, Spain; School of Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, European Way, Southampton, SO14-3ZH, United Kingdom; Géosciences Montpellier, CNRS, Université Montpellier, Place E. Bataillon, Montpellier, 34095, France; Department of Geology, Trinity College Dublin, Dublin 2, Ireland; Mantle Drilling Promotion Office, Institute for Marine-Earth Exploration and Engineering (MarE3), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 3173-25 Showa-machi, Kanazawa-ku, Kanagawa, Yokohama, 236-0001, Japan; Institute for Marine-Earth Exploration and Engineering (MarE3), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), 2-15 Natsushima, Kanagawa, Yokosuka, 237-0061, Japan Exploratory geochemistry; Fluorescence spectroscopy; Inductively coupled plasma; Inductively coupled plasma mass spectrometry; Infill drilling; Laser ablation; Pelletizing; Petrology; Preferred numbers; Rare earths; Rocks; Stratigraphy, Crust mantle; Drilling projects; Laser-ablation inductively-coupled plasma mass spectrometry; Mass spectrometry analysis; New approaches; Oceanic crust; Pressed powder pellets; Trace elements concentration; Traces elements; Ultratraces, Trace elements https://www.scopus.com/inward/record.uri?eid=2-s2.0-85125994511&doi=10.5194%2fsd-30-75-2022&partnerID=40&md5=315c7ac77a0fde9f666b4d46f0825e9e cited By 1 M. Rospabé F. Kourim A. Tamura E. Takazawa M. Giampouras S. Chatterjee K. Ishii M.J. Cooper M. Godard E. Carter N. Abe K. Moe D.A.H. Teagle Oman Drilling Project "ChikyuOman2018 Leg 3"Science Team article Menzel20221191 The reaction of serpentinized peridotite with CO2-bearing fluids to form listvenite (quartz-carbonate rock) requires massive fluid flux and significant permeability despite an increase in solid volume. Listvenite and serpentinite samples from Hole BT1B of the Oman Drilling Project help to understand mechanisms and feedbacks during vein formation in this process. Samples analyzed in this study contain abundant magnesite veins in closely spaced, parallel sets and younger quartz-rich veins. Cross-cutting relationships suggest that antitaxial, zoned magnesite veins with elongated grains growing from a median zone towards the wall rock are among the earliest structures to form during carbonation of serpentinite. Their bisymmetric chemical zoning of variable Ca and Fe contents, a systematic distribution of SiO2 and Fe-oxide inclusions in these zones, and cross-cutting relations with Fe oxides and Cr spinel indicate that they record progress of reaction fronts during replacement of serpentine by carbonate in addition to dilatant vein growth. Euhedral terminations and growth textures of magnesite vein fill, together with local dolomite precipitation and voids along the vein-wall rock interface, suggest that these veins acted as preferred fluid pathways allowing infiltration of CO2-rich fluids necessary for carbonation to progress. Fracturing and fluid flow were probably further enabled by external tectonic stress, as indicated by closely spaced sets of subparallel carbonate veins. Despite widespread subsequent quartz mineralization in the rock matrix and veins, which most likely caused a reduction in the permeability network, carbonation proceeded to completion within listvenite horizons. © 2022 Manuel D. Menzel et al. 2022 English 18699510 10.5194/se-13-1191-2022 Solid Earth 13 Copernicus GmbH 1191-1218 Tectonics and Geodynamics, RWTH Aachen University, Lochnerstrasse 4-20, Aachen, 52056, Germany; Bureau of Economic Geology, The University of Texas at Austin, Austin, TX, United States; Géosciences Montpellier, CNRS, Université de Montpellier, Montpellier, France 8 Carbon dioxide; Flow of fluids; Iron oxides; Magnesia; Magnesite; Mineralogy; Quartz; Rocks; Serpentine; Textures, Carbonate rock; Cross-cutting; Drilling projects; Fe oxide; Fluid fluxes; Quartz + carbonates; Serpentinite; Serpentinized peridotites; Solid volumes; Vein formation, Carbonation, mineralization; ophiolite; peridotite; quartz; serpentinite; serpentinization; zoning, Oman https://www.scopus.com/inward/record.uri?eid=2-s2.0-85135632552&doi=10.5194%2fse-13-1191-2022&partnerID=40&md5=4f073b16e5b5b17664442b223bf829d4 cited By 0 M.D. Menzel J.L. Urai E. Ukar T. Decrausaz M. Godard article kelemen2022ongoing 2022 Authorea Preprints Authorea Peter B Kelemen James A Leong Juan Carlos Obeso Juerg Matter Eric T Ellison Alexis S Templeton Daniel B Nothaft Alireza Eslami Katy Evans Marguerite Godard others article hong2022new 2022 Journal of Geophysical Research: Solid Earth 127 Wiley Online Library e2022JB024379 7 Gilbert Hong Jessica Lynn Till Annika Greve Sang-Mook Lee Oman Drilling Project Phase 2 Science Party article carter2022bimodal 2022 Journal of Geophysical Research: Solid Earth 127 Wiley Online Library e2021JB022669 1 Elliot J Carter Brian O’Driscoll Ray Burgess Patricia L Clay James Hepworth Oman Drilling Project Science Team article kelemen2022listvenite This paper provides an overview of research on core from Oman Drilling Project Hole BT1B and the surrounding area, plus new data and calculations, constraining processes in the Tethyan subduction zone beneath the Samail ophiolite. The area is underlain by gently dipping, broadly folded layers of allochthonous Hawasina pelagic sediments, the metamorphic sole of the Samail ophiolite, and Banded Unit peridotites at the base of the Samail mantle section. Despite reactivation of some faults during uplift of the Jebel Akdar and Saih Hatat domes, the area preserves the tectonic “stratigraphy” of the Cretaceous subduction zone. Gently dipping listvenite bands, parallel to peridotite banding and to contacts between the peridotite and the metamorphic sole, replace peridotite at and near the basal thrust. Listvenites formed at less than 200°C and (poorly constrained) depths of 25–40 km by reaction with CO2-rich, aqueous fluids migrating from greater depths, derived from devolatilization of subducting sediments analogous to clastic sediments in the Hawasina Formation, at 400°–500°. Such processes could form important reservoirs for subducted CO2. Listvenite formation was accompanied by ductile deformation of serpentinites and listvenites—perhaps facilitated by fluid-rock reaction—in a process that could lead to aseismic subduction in some regions. Addition of H2O and CO2 to the mantle wedge, forming serpentinites and listvenites, caused large increases in the solid mass and volume of the rocks. This may have been accommodated by fractures formed as a result of volume changes, mainly at a serpentinization front. © 2022. American Geophysical Union. All Rights Reserved. 2022 English 21699313 10.1029/2021JB022352 Journal of Geophysical Research: Solid Earth 127 Wiley Online Library e2021JB022352 Lamont Doherty Earth Observatory, Columbia University, Palisades, NY, United States; Department of Geosciences, University of Calgary, Calgary, AB, Canada; Géosciences Montpellier, Université de Montpellier, CNRS, Montpellier, France; Kochi Institute for Core Sample Research, JAMSTEC, Kochi, India; Department of Earth & Planetary Sciences, McGill University, Montreal, QC, Canada; Department of Earth, Planetary & Space Sciences, University of California, Los Angeles, CA, United States; Department of Geological Sciences, University of Colorado, Boulder, CO, United States; Tectonics & Geodynamics, RWTH Aachen University, Aachen, Germany; Department of Earth, Environmental and Planetary Sciences, Brown University, Providence, RI, United States; Department of Earth Science, University of California, Santa Barbara, CA, United States; Department of Geological Sciences, University of Texas, Austin, TX, United States; Department of Earth Science, University of Bergen, Bergen, Norway; Department of Ocean & Earth Science, National Oceanography Centre Southampton, Southampton, United Kingdom; Alara Resources Ltd., Muscat, Oman; School of Geography, Earth and Environmental Sciences, University of Plymouth, Plymouth, United Kingdom; Department of Earth & Planetary Sciences, Nagoya University, Nagoya, Japan; Department of Geology, Niigata University & VERC IMG JAMSTEC, Niigata, Japan; Oman Water Society & Middle East Desalination Research Center, Muscat, Oman; Department of Earth and Environmental Sciences, Columbia University, New York, NY, United States; School of Ocean and Earth Science, University of Southampton, Southampton, United Kingdom; Geography, Earth and Environmental Sciences, Plymouth University, Plymouth, United Kingdom; School of Earth and Ocean Sciences, Cardiff University, Cardiff, United Kingdom; Department of Petrology, Center de Recherches Pétrographiques et Géochimiques (CRPG), Vandœuvre-lés-Nancy, France; Department of Geosciences, CRPG-CNRS Université de Lorraine, France; Department of Earth Sciences, Federal Institute of Technology, Zurich, Switzerland; Institute of Geosciences, Christian-Albrecht University of Kiel, Kiel, Germany; Department of Géosciences, CNRS Université de Montpellier, Montpellier, France; Department of Applied Geosciences, German University of Technology in Oman, Oman; Department of Earth, Planetary and Space Sciences, University of California, Los Angeles, CA, United States; Institute for Mineralogy, Leibniz University of Hanover, Hanover, Germany; Institute of Geosciences, Kiel University, Kiel, Germany; Department of Geosciences, Université de Montpellier, Montpellier, France; Department of Geological Sciences, University of Colorado, Boulder, CO, United States; Department of Earth Sciences, Kanazawa University, Kanazawa, Japan; Department of Geosciences, CNRS Université de Montpellier, Montpellier, France; Earth, Ocean and Atmospheric Sciences, University of British Columbia, Vancouver, BC, Canada 2 carbon cycle; drilling; ductile deformation; mantle; mass transfer; ophiolite; subduction zone; ultramafic rock, Oman https://www.scopus.com/inward/record.uri?eid=2-s2.0-85131513917&doi=10.1029%2f2021JB022352&partnerID=40&md5=33a9a1a01c09c7008cae841a58027261 cited By 5 Peter B Kelemen Juan Obeso James A Leong Marguerite Godard Keishi Okazaki Alissa J Kotowski Craig E Manning Eric T Ellison Manuel D Menzel Janos L Urai others article engelhardt2022icdp 2022 European Journal of Mineralogy 34 Copernicus GmbH 603--626 6 Artur Engelhardt Jürgen Koepke Chao Zhang Dieter Garbe-Schönberg Ana Patr{\'\i}cia Jesus article Kourim2022 The transition from the gabbroic oceanic crust to the residual mantle harzburgites of the Oman ophiolite has been drilled at Holes CM1A and CM2B (Wadi Tayin massif) during Phase 2 of the International Continental Scientific Drilling Program Oman Drilling Project (November 2017–January 2018). In order to unravel the formation processes of ultramafic rocks in the Wadi Tayin massif crust-mantle transition zone and deeper in the mantle sections beneath oceanic spreading centers, our study focuses on the whole rock major and trace element compositions (together with CO2 and H2O concentrations) of these ultramafic rocks (56 dunites and 49 harzburgites). Despite extensive serpentinization and some carbonation, most of the trace element contents (REE, HFSE, Ti, Th, U) record high temperature, magmatic process-related signatures. Two major trends are observed, with good correlations between (a) Th and U, Nb and LREE on one hand, and between (b) heavy REE, Ti and Hf on the other hand. We interpret the first trend as the signature of late melt/peridotite interactions as LREE are known to be mobilized by such processes (‘‘lithospheric process’’) and the second trend as the signature of the initial mantle partial melting (‘‘asthenospheric process’’), with little or no overprint from melt/rock reaction events. © 2022. American Geophysical Union. All Rights Reserved. 2022 English 21699313 10.1029/2021JB022694 Journal of Geophysical Research: Solid Earth 127 John Wiley and Sons Inc Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan; Research Institute for Marine Geodynamics (IMG), Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan; Department of Earth & Planetary Sciences, University of Tennessee, Knoxville, TN, United States; Department of Geology, Faculty of Science, Niigata University, Niigata, Japan; Department of Earth Sciences, National Taiwan University, Taipei, Taiwan; Géosciences Montpellier, CNRS, Université Montpellier, Montpellier, France; Géosciences Environnement Toulouse (GET), Observatoire Midi-Pyrénées, Université de Toulouse, CNRS, IRD, Toulouse, France; Instituto Andaluz de Ciencias de la Tierra (IACT), Consejo Superior de Investigaciones Científicas, Universidad de Granada, Granada, Spain; School of Ocean & Earth Science, National Oceanography Centre Southampton, University of Southampton, Southampton, United Kingdom; Lamont–Doherty Earth Observatory, Columbia University, Palisades, NY, United States 4 crust-mantle boundary; drilling; dunite; geochemistry; harzburgite; partial melting; serpentinization; transition zone, Oman https://www.scopus.com/inward/record.uri?eid=2-s2.0-85128721983&doi=10.1029%2f2021JB022694&partnerID=40&md5=0aa7c03846c80d9ec32cf6a22d6c4288 cited By 0 F. Kourim M. Rospabé N. Dygert S. Chatterjee E. Takazawa K.-L. Wang M. Godard M. Benoit M. Giampouras K. Ishii D.A.H. Teagle M.-J. Cooper P. Kelemen article Aiken2022 Serpentinization and carbonation of mantle rocks (peridotite alteration) are fundamentally important processes for a spectrum of geoscience topics, including arc volcanism, earthquake processes, chemosynthetic biological communities, and carbon sequestration. Data from a hydrophone array deployed in the Multi-Borehole Observatory (MBO) of the Oman Drilling Project demonstrates that free gas generated by peridotite alteration and/or microbial activity migrates through the formation in discrete bursts of activity. We detected several, minutes-long, swarms of gas discharge into Hole BA1B of the MBO over the course of a 9 month observation interval. The episodic nature of the migration events indicates that free gas accumulates in the permeable flow network, is pressurized, and discharges rapidly into the borehole when a critical pressure, likely associated with a capillary barrier at a flow constriction, is reached. Our observations reveal a dynamic mode of fluid migration during serpentinization, and highlight the important role that free gas can play in modulating pore pressure, fluid flow, and alteration kinetics during peridotite weathering. © 2022. The Authors. 2022 English 00948276 10.1029/2022GL100395 Geophysical Research Letters 49 John Wiley and Sons Inc Njord Centre, Departments of Physics and Geosciences, University of Oslo, Oslo, Norway; Department of Geology and Geophysics, Woods Hole Oceanographic Institution, Woods Hole, MA, United States; CNRS, IRD, ISTerre, University Grenoble Alpes, Grenoble INP, University Savoie Mont Blanc, University Gustave Eiffel, Grenoble, France; School of Ocean and Earth Science, University of Southampton, Southampton, United Kingdom; Lamont Doherty Earth Observatory, Columbia University, Palisades, NY, United States 21 Acoustics; Boreholes; Flow of fluids; Gases; Groundwater; Rocks; Weathering, Arc volcanism; Earthquake process; Free gas; Gas migration; Geosciences; Mantle rocks; Peridotite alterations; Reaction-driven crackings; Serpentinization; Spectra's, Hydrogeology, borehole; earthquake; hydrogeology; hydrophone; migration; serpentinization, Oman https://www.scopus.com/inward/record.uri?eid=2-s2.0-85141938258&doi=10.1029%2f2022GL100395&partnerID=40&md5=5020b68ffc4fb4d52c7a81fd33753204 cited By 0 J.M. Aiken R.A. Sohn F. Renard J. Matter P. Kelemen B. Jamtveit article WOS:000812995300021 2022 10.1038/s41467-022-31049-1 NATURE COMMUNICATIONS 13 1 Manuel D. Menzel Janos L. Urai Estibalitz Ukar Greg Hirth Alexander Schwedt Andras Kovacs Lidia Kibkalo Peter B. Kelemen article de2022deep 2022 Journal of Geophysical Research: Solid Earth 127 Wiley Online Library e2021JB022704 1 Juan Carlos Obeso Peter B Kelemen James M Leong Manuel D Menzel Craig E Manning Marguerite Godard Yue Cai Louise Bolge Oman Drilling Project Phase 1 Science Party article Garbe-Schönberg2022 Due to its inaccessibility, no complete and coherent data set exists for the composition of modern fast-spreading oceanic crust. We sampled outcrops through 6,500 m of fossil oceanic crust in the Oman Ophiolite (Wadi Gideah Transect) that is regarded as best analogue of fast-spreading crust on land. Here we report a complete set of whole-rock major and trace element data displaying systematic and contrasting compositional trends in lower and upper gabbros being correlated with stratigraphic depth. A significant discontinuity in crystallization regime is observed at ∼3,525 m above the mantle-crust boundary: gabbros below ∼3,525 m have in general very low incompatible element mass fractions which develop upwards in a barely noticeable way to more differentiated compositions while Mg# decreases. More pronounced trends indicating progressive fractionation of ascending melts can be observed for incompatible elements and their element ratios as a consequence of in situ crystallization. Locally, more variable compositions within narrow depth intervals testify for advanced differentiation in situ within individual sills. Gabbros above ∼3,525 m become significantly more evolved and show considerable variations in composition. Fractional crystallization and mixing processes in a transient axial melt lens control the composition of isotropic “varitextured” gabbros and sheeted dike basalts where fractionation of high field strength elemental ratios is minor. New average compositions of fast-spread (paleo) oceanic crust are reported for major and 38 trace elements. Comparison with new data from Wadi Khafifah close to Wadi Gideah suggests robustness of crustal accretion processes in both space and time. © 2022. The Authors. 2022 English 21699313 10.1029/2021JB022734 Journal of Geophysical Research: Solid Earth 127 John Wiley and Sons Inc Institute of Geosciences, Kiel University, Kiel, Germany; Department of Physics and Earth Sciences, Jacobs University Bremen, Bremen, Germany; Institute of Mineralogy, Leibniz University Hannover, Hannover, Germany 6 gabbro; geochemistry; oceanic crust; seafloor spreading; trace element; transect, Oman; Semail Ophiolite https://www.scopus.com/inward/record.uri?eid=2-s2.0-85132874756&doi=10.1029%2f2021JB022734&partnerID=40&md5=dfc8fa5cd05fdcbe4cbfd5fa04a8342e cited By 1 D. Garbe-Schönberg J. Koepke S. Müller D. Mock T. Müller article greenberger2021hydrothermal Processes for formation, cooling, and altering Earth's ocean crust are not yet completely understood due to challenges in access and sampling. Here, we use contiguous micro-imaging infrared spectroscopy to develop complete-core maps of mineral occurrence and investigate spatial patterns in the hydrothermal alteration of 1.2 km of oceanic crust recovered from Oman Drilling Project Holes GT1A, GT2A, and GT3A drilled in the Samail Ophiolite, Oman. The imaging spectrometer shortwave infrared sensor measured reflectance of light at wavelengths 1.0–2.6 μm at 250–260 μm/pixel, resulting in >1 billion independent measurements. We map distributions of nine key primary and secondary minerals/mineral groups—clinopyroxene, amphibole, calcite, chlorite, epidote, gypsum, kaolinite/montmorillonite, prehnite, and zeolite—and find differences in their spatial occurrences and pervasiveness. Accuracy of spectral mapping of occurrence is 68%–100%, established using X-ray diffraction measurements from the core description. The sheeted dikes and gabbros of upper oceanic crust Hole GT3A show more pervasive alteration and alteration dominated by chlorite, amphibole, and epidote. The foliated/layered gabbros of GT2A from intermediate crustal depths have similarly widespread chlorite but more zeolite and little amphibole and epidote. The layered gabbros of the lower oceanic crust (GT1A) have remnant pyroxene and 2X less chlorite, but alteration is extensive within and surrounding major fault zones with widespread occurrences of amphibole. The results indicate greater distribution of higher temperature alteration minerals in the upper oceanic crust relative to deeper gabbros and highlight the importance of fault zones in hydrothermal convection in the lower ocean crust. © 2021. The Authors. 2021 English 21699313 10.1029/2021JB021976 Journal of Geophysical Research: Solid Earth 126 Wiley Online Library e2021JB021976 Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, United States; School of Geography, Earth, and Environmental Sciences, Plymouth University, Plymouth, United Kingdom; Department of Earth & Environmental Sciences, Lamont-Doherty Earth Observatory, Columbia University, Palisades, NY, United States; Department of Earth, Planetary, and Space Sciences, University of California, Los Angeles, CA, United States; School of Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Southampton, United Kingdom 8 dike; gabbro; hydrothermal alteration; imaging method; infrared spectroscopy; mineralization; multispectral image; oceanic crust, Oman https://www.scopus.com/inward/record.uri?eid=2-s2.0-85113707133&doi=10.1029%2f2021JB021976&partnerID=40&md5=5a190e54bd64b6846029a4400c00e8c4 cited By 3 Rebecca N Greenberger Michelle Harris Bethany L Ehlmann Molly A Crotteau Peter B Kelemen Craig E Manning Damon AH Teagle Oman Drilling Project Science Team article koepke2021wet 2021 Tectonophysics 817 Elsevier 229051 J Koepke ST Feig J Berndt DA Neave Oman Drilling Project Science Team others article kotowski2021structural 2021 Journal of Geophysical Research: Solid Earth 126 Wiley Online Library e2021JB021702 12 Alissa J Kotowski Mark Cloos Daniel F Stockli Eytan Bos Orent article Aupart2021 Article 2021 10.1016/j.epsl.2021.117137 Earth and Planetary Science Letters 574 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85114125693&doi=10.1016%2fj.epsl.2021.117137&partnerID=40&md5=27829988feae3c539522f2330848ef2a Cited by: 15; All Open Access, Green Open Access, Hybrid Gold Open Access Claire Aupart Luiz Morales Marguerite Godard Bjørn Jamtveit article france2021quantifying At oceanic spreading centers, the interactions between the igneous system that builds the crust, and the hydrothermal system that cools it govern the plumbing system architecture and its thermokinetic evolution. At fast-spreading centers, most of those interactions occur around the axial magma lens (AML) that feeds the upper crust, and possibly part of the underlying mushy igneous reservoir. Heat extracted from crystallizing AML is transferred through a conductive boundary layer to the overlying hydrothermal system. Quantifying the AML physical and thermal evolutions and its interactions with hydrothermal system is therefore essential to understand oceanic accretion. Those general issues were the rationale of drilling ICDP OmanDP Hole GT3A, and we present herein the geological, structural, and petrological data that were used as a site survey to select its location. GT3 area enables observations in three dimensions of fossilized AMLs and overlying dikes. The new field data and corresponding mineral compositions are used together with thermokinetic and thermodynamic models to deliver an integrated dynamic model for the AML/hydrothermal system interactions. Results attest that the isotropic gabbro interval is composite, with gabbro bodies intruding and reheating both gabbros and dikes (up to 1,040°C). We show that AMLs should be considered as transient igneous bodies that likely crystallize from primitive MORBs in decades, releasing heat to the intruded hosts, and feeding high temperature vents on the seafloor. We show for the first time that the thermal gradient recorded in AML roof is consistent with the heat fluxes reported at active hydrothermal vents. © 2021. The Authors. 2021 English 21699313 10.1029/2020JB021496 Journal of Geophysical Research: Solid Earth 126 Wiley Online Library e2020JB021496 Université de Lorraine, CNRS, CRPG, Nancy, France; Laboratoire Magmas et Volcans, Université Clermont Auvergne - CNRS - IRD, OPGC, Aubière, France; Université de Paris, Institut de Physique du Globe de Paris, CNRS, Paris, France; Institut fuer Mineralogie, Universitaet Hannover, Hannover, Germany; Géosciences Montpellier, Université de Montpellier, CNRS, Montpellier, France; Institute of Earth Sciences, University of Lausanne, Lausanne, Switzerland 5 dike; drilling; gabbro; heat flux; hydrothermal system; hydrothermal vent; magma chamber; seafloor; spreading center; thermal evolution https://www.scopus.com/inward/record.uri?eid=2-s2.0-85106885820&doi=10.1029%2f2020JB021496&partnerID=40&md5=141a88568266015580847fc29e676407 cited By 5 Lyderic France Maéva Lombard Christian Nicollet Carole Berthod Baptiste Debret Juergen Koepke Benoit Ildefonse Aurore Toussaint article Chatterjee2021170 Oxidation states within the planetary interior are intrinsically linked with the broad scale tectonism; however, it is difficult to estimate the actual oxidation conditions. Orthopyroxene-magnetite symplectite formed by olivine oxidation may provide a significant clue into such oxidation events. Here we report detailed mineralogical and petrological synthesis of such orthopyroxene-magnetite symplectites from olivine gabbros of Oman Ophiolite (Hole GT2A, ICDP Oman Drilling Project). In order to understand how oxidation affects different olivine compositions, we employed a phase equilibria approach and computed several temperature-composition diagrams at a fixed pressure (1 kbar). Our experiments predict the coexistence of olivine with Fo75-76 and Fo71 with the orthopyroxene (En79 and En76), respectively, which is remarkably similar to the mineral chemistry obtained from the Oman lower crustal gabbros. From the magnetite content, we also infer that the symplectite formation may have taken place over a range of temperatures (600-1000 °C) via subsolidus olivine oxidation and/or melt (oxidizing)-olivine interaction. The latter is more probable, considering the partial occurrence of orthopyroxene and clinopyroxene rim adjacent to the symplectites. © 2021. All Rights Reserved. 2021 English 13456296 10.2465/jmps.201130f Journal of Mineralogical and Petrological Sciences 116 Tohoku University 170-175 Department of Geology, Faculty of Science, Niigata University, Niigata, 950-2181, Japan; Department of Geology, University of North Bengal, Darjeeling, 734013, India; Department of Geology, University of Calcutta, Kolkata, 700019, India; Japan Agency for Marine-earth Science and Technology, Yokosuka, 237-0061, Japan; Graduate School of Environmental Studies, Nagoya University, Nagoya, 464-8602, Japan 3 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85111248434&doi=10.2465%2fjmps.201130f&partnerID=40&md5=c271395bb3cd26bbcfa68d7166fdb61c cited By 0 S. Chatterjee D. Bandyopadhyay E. Takazawa K. Michibayashi article okazaki2021major We quantified mineral proportions in listvenite (completely carbonated peridotite) in Hole BT1B drilled across the basal thrust of the Samail ophiolite by the International Continental Scientific Drilling Project Oman Drilling Project using 3D X-ray Computed Tomography (XCT). We analyzed >250,000 XCT images from a continuous ∼200 m listvenite core. Histograms of the intensity of X-ray attenuation of each XCT core-slice image were fitted assuming that the listvenites are composed of magnesite, quartz, and dolomite. The XCT mineral peaks were confirmed by comparison with chemical mapping data obtained using an X-ray fluorescence (XRF) core scanner. Listvenite matrix is composed almost entirely of magnesite and quartz, consistent with discrete XRD and XRF data. Veins are composed mostly of dolomite. The mean abundance of dolomite in listvenite from BT1B is 11 vol.%, whereas that in core sections within 15 m of the basal thrust is >50 vol.%, suggesting the basal thrust acted as a source of Ca- and CO2-rich fluids. The SiO2:MgO:CaO molar ratio in the entire core from BT1B is 42:52:6, similar to that of onboard XRF data for discrete samples (41:54:5), whereas average Oman peridotites have ratios of (39:60:1), indicating Ca addition perhaps during carbonation. P- and S-wave velocities and density of listvenite are close to those of peridotite and are higher than those of serpentinites. These results suggest that limited material transfer during carbonation and hydration of the Samail ophiolite, except for Ca, CO2, and H2O. Listvenites formed in the mantle wedge above subduction zones may be an overlooked reservoir for carbon in the Earth's interior. © 2021. American Geophysical Union. All Rights Reserved. 2021 English 21699313 10.1029/2021JB022719 Journal of Geophysical Research: Solid Earth 126 Wiley Online Library e2021JB022719 Kochi Institute for Core Sample Research, X-star, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Kochi, Japan; Department of Earth and Planetary Sciences, Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan; Research Institute for Marine Geodynamics, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan; Department of Education, Meisei University, Tokyo, Japan; Department of Earth and Planetary Systems Science, Hiroshima University, Hiroshima, Japan; Mantle Drilling Promotion Office, MarE3, Japan Agency for Marine-Earth Science and Technology (JAMSTEC), Yokosuka, Japan; Division of Natural System, Graduate School of Natural Science & Technology, Kanazawa University, Kanazawa, Japan; Department of Geology and Geophysics, University of Hawai'i at Mānoa, Honolulu, HI, United States; Marine Geology and Geophysics Division of Ocean Sciences, National Science Foundation, Alexandria, VA, United States; Lamont Doherty Earth Observatory, Columbia University, New York, NY, United States 12 carbon storage; mantle structure; mineral; ophiolite; peridotite; physical property; tectonic plate; X-ray tomography https://www.scopus.com/inward/record.uri?eid=2-s2.0-85129487914&doi=10.1029%2f2021JB022719&partnerID=40&md5=f037e3d0fc5d65cfe4cf064dcdc79add cited By 4 Keishi Okazaki Katsuyoshi Michibayashi Kohei Hatakeyama Natsue Abe Kevin TM Johnson Peter B Kelemen Oman Drilling Project Science Team article ellison2021low 2021 Journal of Geophysical Research: Solid Earth 126 Wiley Online Library e2021JB021981 6 Eric T Ellison Alexis S Templeton Spencer D Zeigler Lisa E Mayhew Peter B Kelemen Juerg M Matter Oman Drilling Project Science Party article kelemen2021initial 2021 Journal of Geophysical Research: Solid Earth 126 Wiley Online Library e2021JB022729 12 Peter B Kelemen James A Leong Juan Obeso Jürg M Matter Eric T Ellison Alexis Templeton Daniel B Nothaft Alireza Eslami Katy Evans Marguerite Godard others article templeton2021accessing 2021 Journal of Geophysical Research: Biogeosciences 126 Wiley Online Library e2021JG006315 10 Alexis S Templeton Eric T Ellison Clemens Glombitza Yuki Morono Kaitlin R Rempfert Tori M Hoehler Spencer D Zeigler Emily A Kraus John R Spear Daniel B Nothaft others article crotteau2021hydration 2021 CaltechDATA Molly A Crotteau Rebecca N Greenberger Bethany L Ehlmann George R Rossman Michelle Harris Peter B Kelemen Damon AH Teagle others article nothaft2021geochemical 2021 Journal of Geophysical Research: Biogeosciences 126 Wiley Online Library e2020JG006025 10 Daniel B Nothaft Alexis S Templeton Jeemin H Rhim David T Wang Jabrane Labidi Hannah M Miller Eric S Boyd Juerg M Matter Shuhei Ono Edward D Young others article godard2021geochemical The transition from the Semail ophiolite mantle to the underlying metamorphic sole was drilled at ICDP OmanDP Hole BT1B. We analyzed the bulk major, volatile and trace element compositions of the mantle-derived listvenite series and metamorphic rocks, with the aim to constrain chemical transfers associated with peridotite carbonation along the ophiolite basal thrust. The listvenite series comprise variously carbonated serpentinites and (fuchsite-bearing) listvenites. They have high CO2 (up to 43 wt.%) and variable H2O (0–12 wt.%). Yet, they have compositions close to that of the basal banded peridotites for most major and lithophile trace elements, with fuchsite-bearing listvenites overlapping in composition with amphibole-bearing basal lherzolites (e.g., Al2O3 = 0.1–2.2 wt.%; Yb = 0.05–1 x CI-chondrite). The protolith of the listvenite series was likely similar in structure and composition to serpentinized banded peridotites which immediately overlie the metamorphic sole elsewhere in Oman. The listvenite series are enriched in fluid mobile elements (FME) compared to Semail peridotites (up to ∼103–104 x Primitive Mantle), with concentrations similar to the underthrusted metabasalts and/or metasediments for Cs, Sr and Ca and sometimes even higher for Pb, Li, As, and Sb (e.g., Li up to 130 μg/g; As up to 170 μg/g). We also observe a decoupling between Sr-Ca enrichments and other FME, indicating interactions with several batches of deep CO2-rich fluids transported along the basal thrust. These results suggest that peridotite carbonation could represent one of the major trap-and-release mechanisms for carbon, water and FME along convergent margins. © 2021. American Geophysical Union. All Rights Reserved. 2021 English 21699313 10.1029/2021JB022733 Journal of Geophysical Research: Solid Earth 126 Wiley Online Library e2021JB022733 Géosciences Montpellier, CNRS, Université de Montpellier, Montpellier, France; Department of Earth and Environmental Sciences, The University of Manchester, Manchester, United Kingdom; Department of Geology, Trinity College Dublin, Dublin, Ireland; School of Earth and Ocean Sciences, Cardiff University, Cardiff, United Kingdom; Academia Sinica, Institute of Earth Science, Taipei, Taiwan; LDEO, Columbia University, Palisades, NY, United States; Department of Earth and Planetary Sciences, Graduate School of Environmental Studies, Nagoya University, Nagoya, Japan; School of Geography, Earth and Environmental Sciences, Plymouth University, Plymouth, United Kingdom; School of Ocean & Earth Science, University of Southampton, Southampton, United Kingdom 12 drilling; metasediment; ophiolite; peridotite; petrogenesis; petrography; serpentinite; serpentinization, Oman https://www.scopus.com/inward/record.uri?eid=2-s2.0-85131386210&doi=10.1029%2f2021JB022733&partnerID=40&md5=905c0708dfe8bda517cc2a0e43f1b5f0 cited By 7 Marguerite Godard EJ Carter T Decrausaz R Lafay E Bennett F Kourim J-C Obeso K Michibayashi M Harris JA Coggon others article hatakeyama2021effects 2021 Journal of Geophysical Research: Solid Earth 126 Wiley Online Library e2021JB021923 11 Kohei Hatakeyama Ikuo Katayama Natsue Abe Keishi Okazaki Katsuyoshi Michibayashi Oman Drilling Project Science Party article katayama2021crack To assess the geometry of cracks in highly altered peridotites, we analyzed the ultrasonic velocity of serpentinized dunites and harzburgites collected by the Oman Drilling Project (Holes BA1B, 3A, and 4A). First, we estimated the hydrated fraction from grain density to obtain the porosity-free matrix velocity, which indicated complete serpentinization at shallow depths and decreasing hydration at greater depths. We assume that the difference between the solid matrix and measured onboard ultrasonic velocity is attributed to cracks with a spheroidal shape in the samples. Application of the effective medium theory to onboard data, such as P-wave velocity and porosity, indicates that the average pore aspect ratio is mostly between 0.1 and 0.01, and crack density varies from 0.58 to 0.02. We found a positive relationship between aspect ratio and hydrated fraction, suggesting a change in crack shape related to dissolution–precipitation processes during hydration. The relatively high aspect ratio and hence high fluid flux at shallow depths are also consistent with the onboard resistivity data and present-day hydration processes inferred from the borehole fluid chemistry. The inversion of ultrasonic data provides a series of elastic moduli that can be used to make a rough approximation of Poisson's ratio from the onboard data, which is a key physical property for interpreting geophysical observations in the oceanic lithosphere. © 2021 The Authors 2021 English 00401951 10.1016/j.tecto.2021.228978 Tectonophysics 814 Elsevier 228978 Department of Earth and Planetary Systems Science, Hiroshima University, Hiroshima, 739-8526, Japan; Mantle Drilling Promotion Office, MarE3, JAMSTECKanagawa 236-0001, Japan; Kochi Institute for Core Sample Research, X-star, JAMSTEC, Kochi, 783-8502, Japan; Graduate School of Environmental Studies, Department of Earth and Planetary Sciences, Nagoya UniversityAichi 464-8602, Japan; Géosciences Montpellier, CNRS, Université de Montpellier, Montpellier, 34095, France; Lamont Doherty Earth Observatory, Columbia University, New York, 10964, United States Boreholes; Hydration; Infill drilling; Matrix algebra; Porosity; Seismic waves; Ultrasonic velocity; Wave propagation, Effective medium theories; Geophysical observations; High aspect ratio; Hydration process; Oceanic lithosphere; Precipitation process; Rough approximations; Serpentinized peridotites, Aspect ratio, cracking (fracture); dunite; fracture geometry; harzburgite; hydration; Poisson ratio; serpentinization; ultrasonics; wave velocity, Oman https://www.scopus.com/inward/record.uri?eid=2-s2.0-85114063954&doi=10.1016%2fj.tecto.2021.228978&partnerID=40&md5=9772e84d84f548f6de37dd72a63a13b9 cited By 1 Ikuo Katayama Natsue Abe Keishi Okazaki Kohei Hatakeyama Yuya Akamatsu Katsuyoshi Michibayashi Marguerite Godard Peter Kelemen The Oman Drilling Project Phase Science Party article crotteau2021characterizing Although ocean crust covers over 60% of Earth's surface, the processes that form, cool, and alter the ocean crust are not completely understood. We utilize shortwave infrared micro-imaging spectroscopy of ∼1.2 km of rock cored by the International Continental Scientific Drilling Program's Oman Drilling Project to quantify hydration of basaltic dikes and gabbros from the Samail ophiolite as a function of depth, mineralogy and deformation. We develop a regression (R2 = 0.66) between area of the ∼1,350–1,650 nm OH/H2O absorption and measurements of loss on ignition of samples and apply this relationship to generate quantitative ∼250 μm/pixel hydration maps for all cores. The lowest mean hydration is observed in the most pervasively altered dike-gabbro boundary (GT3A, H2Omean = 2.1 ± 1.6 wt%), consistent with the low H2O content of the dominant alteration minerals, amphibole and epidote. The highest H2O content occurs in deeper foliated and layered gabbros (GT2A, H2Omean = 3.2 ± 3.0 wt%) and layered gabbros (GT1A, H2Omean = 2.8 ± 3.1 wt%). The greater prevalence with depth of zeolite alteration as opposed to lower wt% H2O amphibole at shallow stratigraphic depths, as well as the occurrence of zones of intensive hydration associated with fault zones (H2Omean = 5.7 ± 4.0 wt%) lead to greater hydration of the lower ocean crust. This new approach provides an objective quantification of hydration in these cores, enabling an improved understanding of quantities and characteristics of ocean crust hydration. It highlights the importance of specific phases and faulting in controlling hydration, which has implications for ocean crust cooling, rheological properties, and the role of alteration in global biogeochemical cycling. © 2021. The Authors. 2021 English 21699313 10.1029/2021JB022676 Journal of Geophysical Research: Solid Earth 126 Wiley Online Library e2021JB022676 Division of Geological and Planetary Sciences, California Institute of Technology, Pasadena, CA, United States; Now at Department of Earth Science, University of California Santa Barbara, Santa Barbara, CA, United States; School of Geography, Earth and Environmental Sciences, Plymouth University, Plymouth, United Kingdom; Department of Earth & Environmental Sciences, Columbia University, Lamont–Doherty Earth Observatory, Palisades, NY, United States; School of Ocean and Earth Science, National Oceanography Centre Southampton, University of Southampton, Southampton, United Kingdom 11 dike; drilling; gabbro; hydration; infrared spectroscopy; oceanic crust; ophiolite; shortwave radiation https://www.scopus.com/inward/record.uri?eid=2-s2.0-85134022652&doi=10.1029%2f2021JB022676&partnerID=40&md5=de43cdd3706ac56462a336d287a33086 cited By 0 Molly A Crotteau Rebecca N Greenberger Bethany L Ehlmann George R Rossman Michelle Harris Peter B Kelemen Damon AH Teagle Oman Drilling Project Phase 1 Science Party article ternieten2021carbon A large part of the hydrated oceanic lithosphere consists of serpentinites exposed in ophiolites. Serpentinites constitute reactive chemical and thermal systems and potentially represent an effective sink for CO2. Understanding carbonation mechanisms within ophiolites are almost exclusively based on studies of outcrops, which can limit the interpretation of fossil hydrothermal systems. We present stable and radiogenic carbon isotope data that provide insights into the isotopic trends and fluid evolution of peridotite carbonation in ICDP Oman Drilling Project drill holes BA1B (400-m deep) and BA3A (300-m deep). Geochemical investigations of the carbonates in serpentinites indicate formation in the last 50 kyr, implying a distinctly different phase of alteration than the initial oceanic hydration and serpentinization of the Samail Ophiolite. The oldest carbonates (∼31 to >50 kyr) are localized calcite, dolomite, and aragonite veins, formed between 26°C and 43°C and related to focused fluid flow. Subsequent pervasive small amounts of dispersed carbonate precipitated in the last 1,000 years. Macroscopic brecciation and veining of the peridotite indicate that carbonation is influenced by tectonic features allowing infiltration of fluids over extended periods and at different structural levels such as along fracture planes and micro-fractures and grain boundaries, causing large-scale hydration of the ophiolite. The formation of dispersed carbonate is related to percolating fluids with δ18O lower than modern ground and meteoric water. Our study shows that radiocarbon investigations are an essential tool to interpret the carbonation history and that stable oxygen and carbon isotopes alone can result in ambiguous interpretations. © 2021 The Authors. 2021 English 21699313 10.1029/2021JB022712 Journal of Geophysical Research: Solid Earth 126 Wiley Online Library e2021JB022712 Department of Earth Sciences, ETH Zurich, Zurich, Switzerland 12 carbon cycle; carbon sequestration; carbonate; drilling; hydrothermal system; radiocarbon dating; serpentinization; temperature anomaly, Oman https://www.scopus.com/inward/record.uri?eid=2-s2.0-85121720934&doi=10.1029%2f2021JB022712&partnerID=40&md5=725bab7f2eee23c048657803579e9a19 cited By 3 Lotta Ternieten Gretchen L Früh-Green Stefano M Bernasconi article nothaft2021aqueous 2021 Journal of Geophysical Research: Biogeosciences 126 Wiley Online Library e2021JG006319 9 Daniel B Nothaft Alexis S Templeton Eric S Boyd Juerg M Matter Martin Stute Amelia N Paukert Vankeuren Oman Drilling Project Science Team article Takazawa2021507 The ICDP Oman Drilling Project carried out onshore drilling of the world's largest ophiolite, the Oman ophiolite (also known as Samail ophiolite). This drilling project provided an opportunity to explore major key boundaries of the oceanic lithosphere, represented by the Oman ophiolite, by drilling cores and boreholes. Below the layered gabbro at the bottom of the crustal section is the Moho Transition Zone(MTZ), which is mainly composed of dunite with small amounts of gabbroic sills. By drilling at the Wadi Zeeb CM site in the Wadi Tayin massif, cores were successfully collected from a 150 m MTZ. Also collected were fragile altered rocks from wadi outcrops that are easily lost. The core description campaign was carried out aboard deep-sea scientific drilling vessel “Chikyu” anchored at Shimizu Port. The core observations were performed and described according to the IODP procedure, and the analysis was conducted using many instruments. The resulting data provide important insights and will contribute to future drilling of the Mohorovicic discontinuity in the ocean. The most striking fact is that MTZ dunites are strongly influenced by serpentinization. In particular, the upper part of the MTZ just below the boundary with the lower crustal gabbro was most strongly altered, and a fracture zone was also developed. Understanding when and how these alterations occurred at the boundary between the crust and the mantle is an important future task. © 2021. All Rights Reserved. 2021 English 0022135X 10.5026/JGEOGRAPHY.130.507 Journal of Geography (Chigaku Zasshi) 130 Tokyo Geographical Society 507-525 Department of Geology, Faculty of Science, Niigata University, Niigata, 950-2181, Japan; Volcanoes and Earth's Interior Research Center, Research Institute for Marine Geodynamics, Japan Agency for Marine-Earth Science and Technology, Yokosuka, 237-0061, Japan 4 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85117418644&doi=10.5026%2fJGEOGRAPHY.130.507&partnerID=40&md5=d2aa6db1c9df9761f53e4d4c76a697d4 cited By 2 E. Takazawa article klaessens2021highly Dunites in ophiolites form by pyroxene dissolution and olivine precipitation during melt-peridotite interaction. We present structural and geochemical data on peridotites from the Batin region (Wadi Tayin massif) of the Oman ophiolite, where an exceptionally large (∼9.5 km long) dunite body was sampled by the ICDP Oman Drilling Project (BA4A borehole). 900–1,200 m beneath the petrological Moho, this dunite is overlain by harzburgite hosting pyroxene-depleted and pyroxene-rich bands. Highly siderophile elements (HSEs) and Os isotopes, excellent tracers of melt flow through peridotites, were measured in dunites and interspersed harzburgites from BA4A borehole. The Batin dunite is structurally and chemically distinct from dunites from the Moho Transition Zone and basal section of the ophiolite, resembling instead sparse dunite veins in the main mantle section. Batin dunites have fairly uniform Os, Ir, and Ru abundances, but Pd and Pt contents increasing with depth. One deep dunite sample has initial 187Os/188Os more radiogenic than MORB. Though the limited number of data demands prudence, we suggest that the Batin dunite formed from a large pulse of radiogenic melts, whose flow was impeded ∼1,200 m below the Moho. As these melts ascended, they may have lost their radiogenic character and relative Pt and Pd enrichment through interaction with peridotites, which have much higher HSE contents than melts. Such interaction would also diminish the under-saturation in pyroxene of the melts, eliminating their capacity to sufficiently dissolve the pyroxene of the host harzburgite to form dunite, thus explaining the upper limit of the dunite at ∼900 m. © 2021. American Geophysical Union. All Rights Reserved. 2021 English 21699313 10.1029/2021JB021977 Journal of Geophysical Research: Solid Earth 126 Wiley Online Library e2021JB021977 Centre de Recherches Pétrographiques et Géochimiques, UMR 7358 CNRS - Université de Lorraine, Vandoeuvre-lès-Nancy, France 10 dunite; mantle structure; ophiolite; osmium isotope; siderophile element https://www.scopus.com/inward/record.uri?eid=2-s2.0-85118436454&doi=10.1029%2f2021JB021977&partnerID=40&md5=874d823a1f7285f042ee993403e2b572 cited By 0 Delphine Klaessens Laurie Reisberg David Jousselin Oman Drilling Project Science Team article malvoisin2020measurement 2020 Journal of Geophysical Research: Solid Earth 125 Wiley Online Library e2019JB018877 5 Benjamin Malvoisin Chang Zhang Othmar Müntener Lukas P Baumgartner Peter B Kelemen Oman Drilling Project Science Party article beinlich2020ultramafic The occurrence of the quartz-carbonate alteration assemblage (listvenite) in ophiolites indicates that ultramafic rock represents an effective sink for dissolved CO2. However, the majority of earlier studies of ultramafic rock carbonation had to rely on the surface exposure of reaction textures and field relationships. Here we present the first observations on ultramafic rock alteration obtained from the 300 m deep BT1B drill hole, ICDP Oman Drilling Project, allowing for a continuous and high-resolution investigation. Hole BT1B recovered continuous drill core intersecting surface alluvium, 200 m of altered ultramafic rock comprising mainly listvenite and minor serpentinite bands at 90 and 180 m depth, and 100 m of the underlying metamorphic sole. Textural evidence suggests that the carbonation of fully serpentinized harzburgite commenced by non-equilibrium growth of spheroidal carbonate characterized by sectorial zoning resulting from radially oriented low-angle boundaries. In the serpentinite, carbonate spheroids are composed of alternating magnesite cores and dolomite rims, whereas texturally similar carbonate in the listvenite is composed of Fe-rich magnesite cores and Ca-Fe-rich magnesite rims. The distinct compositions and mineral inclusions indicate that the carbonation extent was controlled by fluid accessibility resulting in the simultaneous formation of limited carbonate in the serpentinite bands and complete carbonation in the listvenite parts of BT1B. The presence of euhedral magnesite overgrowing spheroidal carbonate in the listvenite suggests near-equilibrium conditions during the final stage of carbonation. The carbonate clumped isotope thermometry constrains carbonate crystallization between 50 °C and 250 °C, implying repeated infiltration of reactive fluids during ophiolite uplift and cooling. ©2020. The Authors. 2020 English 21699313 10.1029/2019JB019060 Journal of Geophysical Research: Solid Earth 125 Wiley Online Library e2019JB019060 Department of Earth Science, University of Bergen, Bergen, Norway; Department of Earth Sciences, Utrecht University, Utrecht, Netherlands; Institute of Earth Sciences, Academia Sinica, Taipei, Taiwan; Institute of Geology and Geoinformation, Geological Survey of Japan, The National Institute of Advanced Industrial Science and Technology, Ibaraki, Japan; Géosciences Montpellier, Université Montpellier, Montpellier, France; Lamont–Doherty Earth Observatory, Columbia University, Palisades, NY, United States 6 carbonate rock; chemical alteration; crystallization; geothermometry; ophiolite; texture; ultramafic rock, Oman https://www.scopus.com/inward/record.uri?eid=2-s2.0-85086498143&doi=10.1029%2f2019JB019060&partnerID=40&md5=1c04d8d80dd248467a8182d06c818b80 cited By 24 Andreas Beinlich Oliver Plümper Esmée Boter Inigo A Müller Fatma Kourim Martin Ziegler Yumiko Harigane Romain Lafay Peter B Kelemen Oman Drilling Project Science Team article cocomazzi2020formation 2020 Minerals 10 MDPI 167 2 Giuseppe Cocomazzi Giovanni Grieco Paola Tartarotti Micol Bussolesi Federica Zaccarini Laura Crispini Oman Drilling Project Science Team article katayama2020permeability Permeability profiles in the crust-mantle sequences of the Samail ophiolite were constructed based on onboard measurements of the electrical resistivity of cores recovered during the Oman Drilling Project. For each sample, we measured dry and brine-saturated resistivity during the description campaign on the drilling vessel Chikyu. Owing to the conductive brine in the pore space, wet resistivity is systematically lower than dry resistivity. The difference between dry and wet resistivity is attributed to the movement of dissolved ions in brine that occupies the pore space. We applied effective medium theory to calculate the volume fraction of pores that contribute to electrical transport. Using an empirical cubic law between transport porosity and permeability, we constructed permeability profiles for the crust-mantle transition zone and the serpentinized mantle sections in the Samail ophiolite. The results indicate that (1) the gabbro sequence has a markedly lower permeability than the underlying mantle sequence; (2) serpentinized dunites have higher permeability than serpentinized harzburgites; and (3) discrete sample permeability is correlated with ultrasonic velocity, suggesting that the permeability variations predominately reflect crack density and geometry. ©2020. American Geophysical Union. All Rights Reserved. 2020 English 21699313 10.1029/2019JB018698 Journal of Geophysical Research: Solid Earth 125 Wiley Online Library e2019JB018698 Department of Earth and Planetary Systems Science, Hiroshima University, Hiroshima, Japan; Mantle Drilling Promotion Office, MarE3, JAMSTEC, Kanagawa, Japan; Kochi Institute for Core Sample Research, JAMSTEC, Kochi, Japan; Department of Geosciences, University of Oslo, Oslo, Norway; Earth and Environmental Sciences, Seoul National University, Seoul, South Korea; Department of Geology, University of Maryland, College Park, MD, United States; Department of Earth and Planetary Sciences, Nagoya University, Aichi, Japan; Géosciences Montpellier, CNRS, Université de Montpellier, Montpellier, France; Lamont Doherty Earth Observatory, Columbia University, New York, NY, United States 8 crust-mantle boundary; dunite; electrical resistivity; gabbro; harzburgite; ophiolite; permeability; porosity; transition zone https://www.scopus.com/inward/record.uri?eid=2-s2.0-85089842179&doi=10.1029%2f2019JB018698&partnerID=40&md5=72c5ef576dc772bad94115a1121d4e9b cited By 9 Ikuo Katayama Natsue Abe Kohei Hatakeyama Yuya Akamatsu Keishi Okazaki Ole Ivar Ulven Gilbert Hong Wenlu Zhu Benoit Cordonnier Katsuyoshi Michibayashi others article lods2020groundwater 2020 Journal of Hydrology 589 Elsevier 125152 Gérard Lods Delphine Roubinet Jürg M Matter Richard Leprovost Philippe Gouze Oman Drilling Project Science Team others article Koepke202021 The Oman ophiolite is regarded as best proxy for accreted oceanic crust from typical fast-spreading ridge systems on land. However, the Oman ophiolite is influenced by initial subduction zone initiation, and the nature of the details of the subduction zone setting is still under controversial debate. While a first magmatic phase shows features of magmatic accretion very similar to those known from the East Pacific Rise, except that the primary melts were slightly water-enriched, a second type of magmatism is characterized by an apparent subduction-zone related imprint, producing rocks like FAB basalts and boninites in the upper crust, as well as cross-cutting gabbronorites and wehrlites in the deeper crust. In this paper, we apply diverse experimental studies in wet tholeiitic and peridotitic systems performed at lower pressures (100 to 500 MPa) in the experimental lab of the University Hannover, in order to constrain the details of the magmatic processes proceeded at the Oman ophiolite paleoridge during the Cretaceous, with special focus on the influence of water on the phase stabilities and phase relations. The experiments were performed in vertically oriented internally heated pressure vessels (IHPV) (see Berndt et al., 2002; Fig. 1). This facility uses as pressure medium mixtures of Ar and H2 in order to adjust the required fH2 in the vessel, enabling us to control the redox conditions. The fH2 prevailing in the IHPV at high P and T was measured with a Shaw-membrane made of platinum. The overall variation in fO2 in all experimental series was in the range between ∼FMQ-1 and ∼FMQ+3.2, thus covering the range of oxygen fugacities prevailing in natural MORB magmas (Bezos and Humler, 2005). For understanding the magmatic processes during the Oman ophiolite paleoridge accretion, transects through the lower (GT1) and middle (GT2) crust have been drilled in the frame of ICDP (International Continental Scientific Drilling Program). Drill sites have been selected in the Wadi Tayin massif, which is known that the influence of magmatic phase 2 characterized by subduction-related primary melts is minimal. Details and progress obtained in the Oman Drilling Project (OmanDP) can be found here: (https://www.omandrilling.ac.uk/). Regarding the first magmatic phase of the processes at the Oman ophiolite paleoridge, a characteristic observation made during the description of the drilled cores GT1 (lower crust) and GT2 (mid-curst) was that quite often layers in the layered gabbro series occur which show the presence of clinopyroxene joining olivine instead of plagioclase (under near liquidus conditions). In terms of lithologies this could be interpreted as presence of wehrlitic crystal mushes as early cumulates instead of troctolitic, which are the typical ones for primary magmatism at typical fast-spreading ridges. This situation could be experimentally simulated by adding a moderate to high water activity to primitive MORB at pressures ≥ 200 MPa, resulting in a shift of the clinopyroxene-in curve to higher temperatures above the plagioclase-in curve (Feig et al. 2006; see Fig. 2). Regarding the second, late-stage magmatic phase, the formation of typical Oman high-Ca-boninites could be experimentally simulated by water-saturated partial melting of Oman harzburgite at 200 MPa and relatively low temperatures between 1100 and 1200°C. Depleted gabbronorites crosscutting layered gabbros of phase 1 magmatism can be regarded as cumulates formed in these boninitic melts. Late wehrlites crosscutting layered gabbro could be produced by accumulation of olivine and clinopyroxene at temperatures between 1040 and 1080°C in a hydrous gabbroic system at pressures > 100 MPa with bulk water content of 2–3 wt%. © 2020 Geological Society of China 2020 English 10009515 10.1111/1755-6724.14439 Acta Geologica Sinica (English Edition) 94 John Wiley and Sons Inc 21-22 Leibniz University Hannover, Hannover, 30167, Germany; University of Tasmania, Hobart, TAS 700, Australia accretion; clinopyroxene; gabbro; geoaccumulation; harzburgite; magmatism; mid-ocean ridge basalt; olivine; ophiolite; partial melting; plagioclase; subduction zone; water content, Arabian Sea; East Pacific Rise; Germany; Gulf of Oman; Hannover; Indian Ocean; Lower Saxony; Pacific Ocean https://www.scopus.com/inward/record.uri?eid=2-s2.0-85095811722&doi=10.1111%2f1755-6724.14439&partnerID=40&md5=0166fe90cac564fbc1959356da340526 cited By 0 J. Koepke S.T. Feig article yao2020high 2020 Journal of Mineralogical and Petrological Sciences 115 Japan Association of Mineralogical Sciences 247--260 3 Yuan Yao Eiichi Takazawa Sayantani Chatterjee Antonin Richard Christophe Morlot Laura Creon Salim Al--Busaidi Katsuyoshi Michibayashi Oman Drilling Project Science Team others article yoshida2020fluid 2020 Journal of Geophysical Research: Solid Earth 125 Wiley Online Library e2020JB020268 11 Kazuki Yoshida Atsushi Okamoto Hiroyuki Shimizu Ryosuke Oyanagi Noriyoshi Tsuchiya Oman Drilling Project Phase 2 Science Party article Kelemen2020 Article 2020 10.1016/j.chemgeo.2020.119628 Chemical Geology 550 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85086503881&doi=10.1016%2fj.chemgeo.2020.119628&partnerID=40&md5=57f2d759208cf4aa81e35d9301de74dc Cited by: 187; All Open Access, Hybrid Gold Open Access Peter B. Kelemen Noah McQueen Jennifer Wilcox Phil Renforth Greg Dipple Amelia Paukert Vankeuren article menzel2020brittle 2020 Journal of Geophysical Research: Solid Earth 125 Wiley Online Library e2020JB020199 10 Manuel D Menzel Janos L Urai Juan Carlos Obeso Alissa Kotowski Craig E Manning Peter B Kelemen Michael Kettermann Ana P Jesus Yumiko Harigane Oman Drilling Project Phase 1 Science Team article Kelemen2019 Review 2019 10.3389/fclim.2019.00009 Frontiers in Climate 1 https://www.scopus.com/inward/record.uri?eid=2-s2.0-85123282754&doi=10.3389%2ffclim.2019.00009&partnerID=40&md5=343e04c6b34e8153ade416eb6bbd5148 Cited by: 407; All Open Access, Gold Open Access Peter Kelemen Sally M. Benson Hélène Pilorgé Peter Psarras Jennifer Wilcox inproceedings jesus2019oxide 2019 Geophysical Research Abstracts 21 Ana P Jesus Juergen Koepke João Mata others inproceedings teagle2019tethyan 2019 Geophysical Research Abstracts 21 Damon Teagle Matthew Cooper Michelle Harris Laura Crispini Peter Kelemen others inproceedings matter2019oman 2019 Geophysical Research Abstracts 21 Juerg Matter Peter Kelemen Damon Teagle Jude Coggon article kelemen2018situ 2018 Energy Procedia 146 Elsevier 92--102 Peter B Kelemen Roger Aines Emma Bennett Sally M Benson Emma Carter Jude A Coggon Juan C De Obeso Ondati Evans Greeshma Gadikota Gregory M Dipple others article kelemen2013scientific 2013 Scientific Drilling 15 Copernicus GmbH 64--71 Peter Kelemen Ali Al Rajhi Marguerite Godard Benoit Ildefonse Jürgen Köpke Chris MacLeod Craig Manning Katsu Michibayashi Sobhi Nasir Everett Shock others