New evidence for crustal accretion in the outer Mariana fore arc: Cretaceous radiolarian cherts and mid-ocean ridge basalt-like lavas

Abstract

Research Article| July 01, 1991 Zircon response to diamond-pressure metamorphism in the Kokchetav massif, USSR J. C. Claoué-Long; J. C. Claoué-Long 1Research School of Earth Sciences, Australian National University, GPO Box 4, Canberra ACT 2601, Australia Search for other works by this author on: GSW Google Scholar N. V. Sobolev; N. V. Sobolev 2Institute of Geology and Geophysics, USSR Academy of Sciences Siberian, Division 630090 Novosibirsk 90, USSR Search for other works by this author on: GSW Google Scholar V. S. Shatsky; V. S. Shatsky 2Institute of Geology and Geophysics, USSR Academy of Sciences Siberian, Division 630090 Novosibirsk 90, USSR Search for other works by this author on: GSW Google Scholar A. V. Sobolev A. V. Sobolev 3Vernadsky Institute of Geochemistry, USSR Academy of Sciences, Kosigin str. 19, 117975 Moscow, USSR Search for other works by this author on: GSW Google Scholar Geology (1991) 19 (7): 710–713. https://doi.org/10.1130/0091-7613(1991)019<0710:ZRTDPM>2.3.CO;2 Article history first online: 02 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 J. C. Claoué-Long, N. V. Sobolev, V. S. Shatsky, A. V. Sobolev; Zircon response to diamond-pressure metamorphism in the Kokchetav massif, USSR. Geology 1991;; 19 (7): 710–713. doi: https://doi.org/10.1130/0091-7613(1991)019<0710:ZRTDPM>2.3.CO;2 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 Ultrahigh-pressure metamorphism of the diamond-bearing gneisses in the Kokchetav massif, USSR, has been dated at 530 ±7 Ma (2&sgr,) by SHRIMP ion-microprobe analysis of metamorphic zircons. Zircon xenocrysts as old as 2000 Ma have retained original isotopic compositions through the extreme metamorphic conditions and indicate that the protolith that was buried to diamond-forming pressures included Early Proterozoic components. Highly variable reset-ting of U-Pb isotopic systems in zircon xenocrysts at the time of metamorphism suggests that diffusive lead loss had commenced but was incomplete, a disequilibrium observation consistent with relatively transient exposure of the rocks to extreme crustal depths. This content is PDF only. Please click on the PDF icon to access. First Page Preview Close Modal You do not have access to this content, please speak to your institutional administrator if you feel you should have access.