Growth of subcontinental lithospheric mantle beneath Zimbabwe started at or before 3.8 Ga: Re-Os study on chromites

Abstract

Research Article| November 01, 1997 Growth of subcontinental lithospheric mantle beneath Zimbabwe started at or before 3.8 Ga: Re-Os study on chromites Th. F. Nägler; Th. F. Nägler 1Gruppe Isotopengeologie, Mineralogisch-Petrographisches Institut, Universität Bern, CH-3012 Bern, Switzerland Search for other works by this author on: GSW Google Scholar J. D. Kramers; J. D. Kramers 1Gruppe Isotopengeologie, Mineralogisch-Petrographisches Institut, Universität Bern, CH-3012 Bern, Switzerland Search for other works by this author on: GSW Google Scholar B. S. Kamber; B. S. Kamber 2Department of Earth Sciences, University of Oxford, Parks Road, Oxford, OX1 3PR, United Kingdom Search for other works by this author on: GSW Google Scholar R. Frei; R. Frei 1Gruppe Isotopengeologie, Mineralogisch-Petrographisches Institut, Universität Bern, CH-3012 Bern, Switzerland Search for other works by this author on: GSW Google Scholar M. D. A. Prendergast M. D. A. Prendergast 3M. D. Prendergast Consultancy, Greendale, Harare, Zimbabwe Search for other works by this author on: GSW Google Scholar Geology (1997) 25 (11): 983–986. https://doi.org/10.1130/0091-7613(1997)025<0983:GOSLMB>2.3.CO;2 Article history first online: 02 Jun 2017 Cite View This Citation Add to Citation Manager Share Icon Share MailTo Twitter LinkedIn Tools Icon Tools Get Permissions Search Site Citation Th. F. Nägler, J. D. Kramers, B. S. Kamber, R. Frei, M. D. A. Prendergast; Growth of subcontinental lithospheric mantle beneath Zimbabwe started at or before 3.8 Ga: Re-Os study on chromites. Geology 1997;; 25 (11): 983–986. doi: https://doi.org/10.1130/0091-7613(1997)025<0983:GOSLMB>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 Re-Os isotope results on chromites separated from age-constrained Archean (2.7 to 3.5 Ga) ultramafic intrusions in the Zimbabwe craton show that chromites average a present-day 187Os/188Os ratio of 0.1066, significantly below the bulk silicate Earth value. The source reservoir is interpreted to reflect the Zimbabwean subcontinental lithospheric mantle (SCLM). Archean Re depletion of the SCLM has previously been postulated on the basis of xenolith studies from southern Africa, Siberia, and the Wyoming craton. Because our samples are age constrained, however, the Re-Os data also shed light on the evolution of the Archean SCLM through time. They indicate that the Zimbabwean SCLM began to be separated from asthenospheric mantle before 3.8 Ga and grew quasi-continuously throughout the Archean. This result is reconciled with present-day SCLM data in forward modeling. 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.