- Title
- Primary controls on iron and manganese distribution in sphalerite of the Gams Formation, Gamsberg zinc deposit, Namaqualand, South Africa
- Creator
- Poignant-Molina, Léo
- Subject
- Sphalerite
- Subject
- Sphalerite South Africa Gamsberg
- Subject
- Manganese South Africa Gamsberg
- Subject
- Zinc mines and mining South Africa Gamsberg
- Subject
- Geochemistry South Africa Gamsberg
- Subject
- Metamorphism (Geology)
- Subject
- Electron probe microanalysis
- Date Issued
- 2018
- Date
- 2018
- Type
- text
- Type
- Thesis
- Type
- Masters
- Type
- MSc
- Identifier
- http://hdl.handle.net/10962/63775
- Identifier
- vital:28488
- Description
- The Gamsberg deposit is a 200 Mt zinc reserve belonging to the world class base metalrich Aggeneys-Gamsberg mining district. A rifting environment permitted the development of four proximal SEDEX-type deposits whereby Gamsberg is localized in the eastern side of the district and characterised by a peculiar enrichment in manganese. This study investigates the geochemistry of sphalerite in the Gams Formation holding the economic units of the deposit. Microscopic petrography revealed that most of primary textures have been overprinted by recrystallization, alteration, replacement and deformational textures produced during the polyphase metamorphism of the Namaquan Orogeny. Therefore, EPMA analysis provided the bulk of information to define the geochemical distribution of sphalerite. A lateral variation was noticed throughout the Gams Formation, whereby the North orebody presents Zn-rich and Fe+Mn-poor sphalerite while the West and East orebodies contain Zn-poor and Fe-Mn-rich sphalerite. This feature has been interpreted as the association of a chemocline and a variation in the basin topography defining deep Mn+Fe-rich zones and shallow Mn+Fe-poor zones in the primitive basin. It is suggested that mineralized hot brines mixed with seawater developed the chemocline. The uneven topography shaped the geochemical variation between the actual orebodies.
- Format
- 96 pages
- Format
- Publisher
- Rhodes University
- Publisher
- Faculty of Science, Geology
- Language
- English
- Rights
- Poignant-Molina, Léo
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