Title: Evidence for a 2 Ga subduction zone: Eclogites in the Usagaran belt of Tanzania
Abstract: Research Article| December 01, 1995 Evidence for a 2 Ga subduction zone: Eclogites in the Usagaran belt of Tanzania Andreas Möller; Andreas Möller 1Mineralogisch-Petrographisches Institut, Universität Kiel, 24098 Kiel, Germany2Max-Planck-Institut für Chemie, Postfach 3060, 55020 Mainz, Germany Search for other works by this author on: GSW Google Scholar Peter Appel; Peter Appel 1Mineralogisch-Petrographisches Institut, Universität Kiel, 24098 Kiel, Germany Search for other works by this author on: GSW Google Scholar Klaus Mezger; Klaus Mezger 2Max-Planck-Institut für Chemie, Postfach 3060, 55020 Mainz, Germany Search for other works by this author on: GSW Google Scholar Volker Schenk Volker Schenk 1Mineralogisch-Petrographisches Institut, Universität Kiel, 24098 Kiel, Germany Search for other works by this author on: GSW Google Scholar Author and Article Information Andreas Möller 1Mineralogisch-Petrographisches Institut, Universität Kiel, 24098 Kiel, Germany2Max-Planck-Institut für Chemie, Postfach 3060, 55020 Mainz, Germany Peter Appel 1Mineralogisch-Petrographisches Institut, Universität Kiel, 24098 Kiel, Germany Klaus Mezger 2Max-Planck-Institut für Chemie, Postfach 3060, 55020 Mainz, Germany Volker Schenk 1Mineralogisch-Petrographisches Institut, Universität Kiel, 24098 Kiel, Germany Publisher: Geological Society of America First Online: 02 Jun 2017 Online ISSN: 1943-2682 Print ISSN: 0091-7613 Geological Society of America Geology (1995) 23 (12): 1067–1070. https://doi.org/10.1130/0091-7613(1995)023<1067:EFAGSZ>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 Email Permissions Search Site Citation Andreas Möller, Peter Appel, Klaus Mezger, Volker Schenk; Evidence for a 2 Ga subduction zone: Eclogites in the Usagaran belt of Tanzania. Geology 1995;; 23 (12): 1067–1070. doi: https://doi.org/10.1130/0091-7613(1995)023<1067:EFAGSZ>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 U-Pb geochronology on metamorphic minerals from a 35-km-long belt of eclogite-facies rocks in central Tanzania yields a Paleoproterozoic age of 2 Ga for the time of metamorphism. Peak metamorphic conditions found in eclogites (± kyanite) and metapelites reached about 750 °C and 18 kbar. A clockwise pressure-temperature path is deduced from mineral zonations, inclusion relations, and retrograde reaction textures. Near-isothermal decompression can be explained by erosion or tectonically controlled exhumation that followed tectonic thickening of the crust during subduction. Trace and rare earth element geochemistry indicates a mid-ocean ridge basaltlike mantle source for the precursors of the mafic members of the eclogite-facies rock suite. All the observations combined indicate that these high-pressure rocks are the oldest-known large-scale outcrops of eclogites formed during subduction of oceanic lithosphere. Linking eclogite formation to a Paleoproterozoic subduction event adds credibility to models of crust dynamics that advocate the operation of plate-tectonic processes early in Earth's history. The paucity of Precambrian eclogites may then be addressed as a problem of preservation rather than lack of formation. 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.
Publication Year: 1995
Publication Date: 1995-01-01
Language: en
Type: article
Indexed In: ['crossref']
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Cited By Count: 199
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