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P-T conditions and the origin of quartzo-feldspathic veins in metasyenites from the Central Zone of the Limpopo Belt, South Africa

2008; Geological Society of South Africa; Volume: 111; Issue: 2-3 Linguagem: Inglês

10.2113/gssajg.111.2-3.313

1996-8590

M. Rigby, Hassina Mouri, G. Brandl,

earthquake and tectonic studies

Research Article| September 01, 2008 P-T conditions and the origin of quartzo-feldspathic veins in metasyenites from the Central Zone of the Limpopo Belt, South Africa Martin Rigby; Martin Rigby Department of Geology, University of Pretoria, 0002, South Africa, e-mail: martin.rigby@up.ac.za Search for other works by this author on: GSW Google Scholar Hassina Mouri; Hassina Mouri Department of Geology, University of Pretoria, 0002, South Africa Search for other works by this author on: GSW Google Scholar Günther Brandl Günther Brandl Council for Geoscience, Limpopo Unit, Polokwane, South Africa, e-mail: gbrandl@geoscience.org.za Search for other works by this author on: GSW Google Scholar Author and Article Information Martin Rigby Department of Geology, University of Pretoria, 0002, South Africa, e-mail: martin.rigby@up.ac.za Hassina Mouri Department of Geology, University of Pretoria, 0002, South Africa Günther Brandl Council for Geoscience, Limpopo Unit, Polokwane, South Africa, e-mail: gbrandl@geoscience.org.za Publisher: Geological Society of South Africa First Online: 09 Mar 2017 Online ISSN: 1996-8590 Print ISSN: 1012-0750 © 2007 Geological Society of South Africa South African Journal of Geology (2008) 111 (2-3): 313–332. https://doi.org/10.2113/gssajg.111.2-3.313 Article history First Online: 09 Mar 2017 Cite View This Citation Add to Citation Manager Share Icon Share Facebook Twitter LinkedIn Email Permissions Search Site Citation Martin Rigby, Hassina Mouri, Günther Brandl; P-T conditions and the origin of quartzo-feldspathic veins in metasyenites from the Central Zone of the Limpopo Belt, South Africa. South African Journal of Geology 2008;; 111 (2-3): 313–332. doi: https://doi.org/10.2113/gssajg.111.2-3.313 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 In this study, we present petrological data from metasyenites in the Central Zone of the Limpopo Belt, South Africa. Results from conventional thermobarometry and pseudosection modelling in the chemical system Na2O-CaO-K2O-FeO-MgO-Al2O3-H2O-TiO2-Fe2O3 (NCKFMASHTO) indicate the rocks underwent a metamorphic evolution that was characterised by a maximum pressure of 8 kbar and temperatures of ~770°C. Subsequent retrogression involved a simultaneous P-T decrease via decompression-cooling to 4 kbar at temperatures <550°C. The inferred P-T path, in combination with previous petrological data from Venetia and Messina can be interpreted to support the existence of a metamorphic field gradient that was developed during a single metamorphic event. The metasyenitic body is cross-cut by a number of quartzo-feldspathic veins that probably represent mobilised melt from the surrounding Alldays gneiss. An in-situ partial melt origin for the quartzo-feldspathic veins is ruled-out on the basis of modelling which suggests the measured compositions could not have been derived from the partial melting of the metasyenite. Modelling suggests the metasyenite could theoretically melt at the P-T conditions attained. However, due to a lack of available H2O, melting did not proceed. You do not have access to this content, please speak to your institutional administrator if you feel you should have access.