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Single stage, late Archaean exhumation of granulites in the Northern Marginal Zone, Limpopo Belt, Zimbabwe, and relevance to gold mineralization at Renco mine

2004; Geological Society of South Africa; Volume: 107; Issue: 3 Linguagem: Inglês

10.2113/107.3.377

1996-8590

Thomas G. Blenkinsop,

Geological and Geophysical Studies

Research Article| September 01, 2004 Single stage, late Archaean exhumation of granulites in the Northern Marginal Zone, Limpopo Belt, Zimbabwe, and relevance to gold mineralization at Renco mine Tom G. Blenkinsop; Tom G. Blenkinsop Department of Geology, University of Zimbabwe, P.O. Box MP 167, Mount Pleasant, Harare, Zimbabwe, Present Address: School of Earth Sciences, James Cook University, Townsville, Queensland QLD 4811 Australia, e-mail: Thomas.Blenkinsop@jcu.edu.au Search for other works by this author on: GSW Google Scholar A. Kröner; A. Kröner Department of Geology, University Mainz, Mainz, Germany, e-mail: kroener@mail.uni-mainz.de Search for other works by this author on: GSW Google Scholar V. Chiwara V. Chiwara Rio Tinto, Zimbabwe, PO Box AY 266, Harare, Zimbabwe, e-mail: Victor.Chiwara@riotinto.com Search for other works by this author on: GSW Google Scholar Author and Article Information Tom G. Blenkinsop Department of Geology, University of Zimbabwe, P.O. Box MP 167, Mount Pleasant, Harare, Zimbabwe, Present Address: School of Earth Sciences, James Cook University, Townsville, Queensland QLD 4811 Australia, e-mail: Thomas.Blenkinsop@jcu.edu.au A. Kröner Department of Geology, University Mainz, Mainz, Germany, e-mail: kroener@mail.uni-mainz.de V. Chiwara Rio Tinto, Zimbabwe, PO Box AY 266, Harare, Zimbabwe, e-mail: Victor.Chiwara@riotinto.com Publisher: Geological Society of South Africa First Online: 07 Mar 2017 Online ISSN: 1996-8590 Print ISSN: 1012-0750 © 2004 Geological Society of South Africa South African Journal of Geology (2004) 107 (3): 377–396. https://doi.org/10.2113/107.3.377 Article history First Online: 07 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Tom G. Blenkinsop, A. Kröner, V. Chiwara; Single stage, late Archaean exhumation of granulites in the Northern Marginal Zone, Limpopo Belt, Zimbabwe, and relevance to gold mineralization at Renco mine. South African Journal of Geology 2004;; 107 (3): 377–396. doi: https://doi.org/10.2113/107.3.377 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 SocietySouth African Journal of Geology Search Advanced Search Abstract Detailed field mapping and geochronological studies in the Renco mine area of the Northern Marginal Zone of the Limpopo Belt allow two distinct tectonic events to be distinguished in the late Archaean to Palaeoproterozoic. In the first event, granulite-facies metamorphism (~2720 to ~2590 Ma) was followed by the formation of pervasive steep fabrics accommodating north-northwest shortening, and a network of amphibolite-facies shear zones. Enderbitic rocks were intruded over the interval ~2739 to ~2571 Ma, and granites were intruded over a largely overlapping period of ~2654 to ~2517 Ma. The intrusion of syn-tectonic granites (~2600 to ~2500 Ma) allows the convergent tectonics to be dated as late Archaean. The second event produced deformation zones dominated by cataclasis at maximum temperatures of 400°C, and may have involved localized pseudotachylite generation. These deformation zones have maximum lengths and widths of several hundred metres and 2m respectively: they are separated along and across strike by several kilometres, and did not accommodate significant crustal displacement. They probably formed in the second event at ~2000 Ma. The granulites were therefore exhumed in the first event, following directly on granulite-facies metamorphism, implying that a substantial crustal thickness was attained in the late Archaean. Amphibolite facies gold mineralization at Renco mine probably occurred at this time, followed by Palaeoproterozoic remobilization. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.