Portal de Periódicos da CAPES

In situ peridotitic diamond in Indus ophiolite sourced from hydrocarbon fluids in the mantle transition zone

2017; Geological Society of America; Linguagem: Inglês

10.1130/g39100.1

1943-2682

Souvik Das, Asish R. Basu, Barun K. Mukherjee,

Geological and Geochemical Analysis

Research Article| June 09, 2017 In situ peridotitic diamond in Indus ophiolite sourced from hydrocarbon fluids in the mantle transition zone S. Das; S. Das 1Department of Earth and Environmental Sciences, University of Texas at Arlington, Arlington, Texas 76019, USA Search for other works by this author on: GSW Google Scholar A.R. Basu; A.R. Basu 1Department of Earth and Environmental Sciences, University of Texas at Arlington, Arlington, Texas 76019, USA Search for other works by this author on: GSW Google Scholar B.K. Mukherjee B.K. Mukherjee 2Wadia Institute of Himalayan Geology, Dehradun-248001, India Search for other works by this author on: GSW Google Scholar Author and Article Information S. Das 1Department of Earth and Environmental Sciences, University of Texas at Arlington, Arlington, Texas 76019, USA A.R. Basu 1Department of Earth and Environmental Sciences, University of Texas at Arlington, Arlington, Texas 76019, USA B.K. Mukherjee 2Wadia Institute of Himalayan Geology, Dehradun-248001, India Publisher: Geological Society of America Received: 27 Feb 2017 Revision Received: 25 Apr 2017 Accepted: 29 Apr 2017 First Online: 23 Jun 2017 Online Issn: 1943-2682 Print Issn: 0091-7613 © 2017 Geological Society of America Geology (2017) 45 (8): 755–758. https://doi.org/10.1130/G39100.1 Article history Received: 27 Feb 2017 Revision Received: 25 Apr 2017 Accepted: 29 Apr 2017 First Online: 23 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation S. Das, A.R. Basu, B.K. Mukherjee; In situ peridotitic diamond in Indus ophiolite sourced from hydrocarbon fluids in the mantle transition zone. Geology 2017;; 45 (8): 755–758. doi: https://doi.org/10.1130/G39100.1 Download citation file: Ris (Zotero) Refmanager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentBy SocietyGeology Search Advanced Search Abstract In recent years ophiolitic diamonds have been reported mostly from podiform chromitites. However, the mechanism of such diamond formation remains unknown. We report in situ diamond, graphite pseudomorphs after diamond crystals, and hydrocarbon (C-H) and hydrogen (H2) fluid inclusions in ultrahigh-pressure (UHP) peridotitic minerals of the Nidar ophiolite, Indus suture zone. Diamond occurs as octahedral inclusion along with nitrogen (N2) in orthoenstatite. Methane (CH4) also occurs with UHP clinoenstatite (>8 GPa) in orthoenstatite. The graphite pseudomorphs after diamond crystals and primary hydrocarbon (C-H), and hydrogen (H2) fluids are included in olivine. Oriented hematite (α-Fe2O3) exsolutions are also present in the olivines, indicating a precursory β-Mg2SiO4 phase of the host olivines. This assemblage of diamond, graphite, C-H and H2 has not previously been reported from any ophiolitic peridotite. The hydrocarbon fluids in UHP clinoenstatites and retrogressed β-Mg2SiO4 strongly suggest their source from the mantle transition zone or base of the upper mantle. We conclude that the peridotitic diamonds precipitated from C-H fluids during mantle upwelling beneath the Neo-Tethys Ocean spreading center. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.