Geochemical Characterization of the Oman Crust-Mantle Transition Zone, OmanDP Holes CM1A and CM2B

Type Article
Date 2022-04
Language English
Author(s) Kourim F.1, Rospabé MathieuORCID2, Dygert N.3, Chatterjee S.4, Takazawa E.4, Wang K. L.1, 5, Godard M.6, Benoit M.7, Giampouras M.8, Ishii K.4, Teagle D. A. H.9, Cooper M. J.9, Kelemen P.10
Affiliation(s) 1 : Acad Sinica, Inst Earth Sci, Taipei, Taiwan.
2 : Japan Agcy Marine Earth Sci & Technol JAMSTEC, Res Inst Marine Geodynam IMG, Yokosuka, Kanagawa, Japan.
3 : Univ Tennessee, Dept Earth & Planetary Sci, Knoxville, TN USA.
4 : Niigata Univ, Fac Sci, Dept Geol, Niigata, Japan.
5 : Natl Taiwan Univ, Dept Earth Sci, Taipei, Taiwan.
6 : Univ Montpellier, CNRS, Geosci Montpellier, Montpellier, France.
7 : Univ Toulouse, CNRS, IRD, Geosci Environm Toulouse GET,Observ Midi Pyrenees, Toulouse, France.
8 : Univ Granada, CSIC, Inst Andaluz Ciencias Tierra IACT, Granada, Spain.
9 : Univ Southampton, Natl Oceanog Ctr Southampton, Sch Ocean & Earth Sci, Southampton, Hants, England.
10 : Columbia Univ, Lamont Doherty Earth Observ, Palisades, NY USA.
Source Journal Of Geophysical Research-solid Earth (2169-9313) (Amer Geophysical Union), 2022-04 , Vol. 127 , N. 4 , P. e2021JB022694 (26p.)
DOI 10.1029/2021JB022694
WOS© Times Cited 2
Note This article also appears in: Ophiolites and Oceanic Lithosphere, With a Focus on the Samail Ophiolite in Oman
Keyword(s) partial melting versus melt-rock reaction, dunites and harzburgites serpentinization and carbonation, Oman ophiolite crust-mantle transition, holes CM1A and CM2B, ICDP Oman drilling project
Abstract

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.

Full Text
File Pages Size Access
Publisher's official version 26 3 MB Open access
Supporting Information S1 99 KB Open access
Table S1 30 KB Open access
Table S2 52 KB Open access
Top of the page

How to cite 

Kourim F., Rospabé Mathieu, Dygert N., Chatterjee S., Takazawa E., Wang K. L., Godard M., Benoit M., Giampouras M., Ishii K., Teagle D. A. H., Cooper M. J., Kelemen P. (2022). Geochemical Characterization of the Oman Crust-Mantle Transition Zone, OmanDP Holes CM1A and CM2B. Journal Of Geophysical Research-solid Earth, 127(4), e2021JB022694 (26p.). Publisher's official version : https://doi.org/10.1029/2021JB022694 , Open Access version : https://archimer.ifremer.fr/doc/00773/88506/