Geochemical identification of episodes of gold mineralisation in the Barberton Greenstone Belt, South Africa
| Autor: | Roger D. Dixon, Roland K. W. Merkle, M.A.H. Altigani |
|---|---|
| Rok vydání: | 2016 |
| Předmět: |
Mineralization (geology)
010504 meteorology & atmospheric sciences Geochemistry Mineralogy Geology Greenstone belt Mineral chemistry engineering.material 010502 geochemistry & geophysics 01 natural sciences Hydrothermal circulation Geochemistry and Petrology Boiling process engineering Economic Geology Pyrite Quartz 0105 earth and related environmental sciences |
| Zdroj: | Ore Geology Reviews. 75:186-205 |
| ISSN: | 0169-1368 |
| DOI: | 10.1016/j.oregeorev.2015.12.016 |
| Popis: | The morphology and mineral chemistry of gold and associated sulphides at Sheba, Fairview, and New Consort gold mines in the Barberton Greenstone Belt (BGB) identify two main types of mineralization. The first type occurs associated with sulphides (mainly pyrite), either as inclusions (10–30 μm) or as sub-microscopic gold. The second gold type consists of large gold grains (≥ 100 μm) within the silicates (mostly quartz). LA-ICP-MS studies reveal that some gold and associated sulphide grains contain high values of Cl, Br, Na, and I. The elemental relationships reflect the different chemistry and precipitation processes of possible source fluids, and identify several episodes of mineralisation in the study area, one of them formed due to a boiling process in a supercritical hydrothermal environment. This paper reports on the compositional characteristics of these gold grains, the significance of the halogen contents, and the implications for possible sources of the gold and associated sulphides. |
| Databáze: | OpenAIRE |
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