Hypozonal orogenic gold mineralization in the Giyani Goldfield, Northern Kaapvaal Craton/Limpopo Complex
Autor: | C.A. Smit, Steve McCourt, N.A. Vafeas, G.A. Belyanin, D. D. van Reenen, Jan Marten Huizenga |
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Rok vydání: | 2019 |
Předmět: |
geography
Mineralization (geology) geography.geographical_feature_category 010504 meteorology & atmospheric sciences Metamorphic rock Geochemistry Geology Orogeny Greenstone belt 010502 geochemistry & geophysics 01 natural sciences Tectonics Craton Metasomatism Shear zone 0105 earth and related environmental sciences |
Zdroj: | South African Journal of Geology. 122:455-488 |
ISSN: | 1996-8590 1012-0750 |
Popis: | The paper reviews published and unpublished geological data pertaining to the structural and metamorphic controls, rock types, characteristic features, source, and timing of hypozonal orogenic gold mineralization in the Giyani Goldfield. The Giyani Goldfield includes the NW domain of the >3.0 Ga Giyani greenstone belt (GGB) at the northern edge of the Kaapvaal Craton and the southern retrograde hydrated domain of the juxtaposed Southern Marginal Zone (SMZ) of the ca. 2.72 Ga Limpopo Complex (LC). Mineralization at all gold mines and gold prospects of the Giyani Goldfield is structurally controlled and closely associated with the Hout River shear zone (HRSZ) and associated smaller shear zones suggesting a specific tectonic setting. This tectonic setting is the direct consequence of thrusting the SMZ of the LC against and over the adjacent GGB at the position of the steeply north-dipping (south verging) HRSZ during the exhumation stage of the ca. 2.72 to 2.69 Ga Limpopo orogeny followed by regional retrograde hydration of the southern part of the SMZ at ca. 2.68 to 2.62 Ga. This tectonic setting offers an explanation for a deep-seated crustal source for gold and for the concentration of orogenic gold mineralization within specific structural features located within the Giyani Goldfield. This tectonic setting also explains the lithological, structural and metamorphic complexity, metasomatic alteration and post-peak metamorphic timing of gold mineralization. Finally, it provides important clues with regards to a crustal source for gold mineralizing fluids and the identification of new potential targets for gold exploration in the Giyani Goldfield. |
Databáze: | OpenAIRE |
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