Diamond- and coesite-bearing chromitites from the Luobusa ophiolite, Tibet

Research Article| October 01, 2007 Diamond- and coesite-bearing chromitites from the Luobusa ophiolite, Tibet Jing-Sui Yang; Jing-Sui Yang 1Key Laboratory for Continental Dynamics, Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China Search for other works by this author on: GSW Google Scholar Larissa Dobrzhinetskaya; Larissa Dobrzhinetskaya 2Department of Earth Sciences and Institute of Geophysics and Planetary Physics, University of California–Riverside, Riverside, California 92521, USA Search for other works by this author on: GSW Google Scholar Wen-Ji Bai; Wen-Ji Bai 3Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China Search for other works by this author on: GSW Google Scholar Qing-Song Fang; Qing-Song Fang 3Institute of Geology, Chinese Academy of Geological Sciences, Beijing 100037, China Search for other works by this author on: GSW Google Scholar Paul T. Robinson; Paul T. Robinson 4GeoForschungsZentrum, Telegrafenberg, D-14473 Potsdam, Germany Search for other works by this author on: GSW Google Scholar Junfeng Zhang; Junfeng Zhang 5Department of Earth Sciences and Institute of Geophysics and Planetary Physics, University of California–Riverside, Riverside, California 92521, USA Search for other works by this author on: GSW Google Scholar Harry W. Green, II Harry W. Green, II 5Department of Earth Sciences and Institute of Geophysics and Planetary Physics, University of California–Riverside, Riverside, California 92521, USA Search for other works by this author on: GSW Google Scholar Geology (2007) 35 (10): 875–878. https://doi.org/10.1130/G23766A.1 Article history received: 02 Feb 2007 rev-recd: 08 May 2007 accepted: 13 May 2007 first online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn MailTo Tools Icon Tools Get Permissions Search Site Citation Jing-Sui Yang, Larissa Dobrzhinetskaya, Wen-Ji Bai, Qing-Song Fang, Paul T. Robinson, Junfeng Zhang, Harry W. Green; Diamond- and coesite-bearing chromitites from the Luobusa ophiolite, Tibet. Geology 2007;; 35 (10): 875–878. doi: https://doi.org/10.1130/G23766A.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 Diamonds and other ultrahigh pressure (UHP) minerals have been reported previously from the Luobusa ophiolite of Tibet, but these minerals have thus far been found only as individual grains. Here we report the occurrence of diamond as an inclusion in OsIr alloy and coesite as part of a silicate assemblage rimming a grain of FeTi alloy, both of which were recovered from chromitite. These occurrences confirm the presence of UHP minerals in the Luobusa chromitite requiring minimum pressures of ∼2.8–4 GPa. Individual coesite “crystals” have external form similar to that of stishovite and are polycrystalline, suggesting pseudo morphic replacement and implying a pressure >9 GPa. We propose that the UHP minerals were incorporated into the chromitites in the deep upper mantle or that they have an impact origin; the preponderance of evidence favors the former. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.