M. Sc. / The Pering Pb-Zn deposit is hosted in the stromatolitic dolomites of the Campbellrand Subgroup of the Ghaap Group, Transvaal Supergroup. The deposit is situated 20 km northeast of the town Reivilo in the semi-arid region of the Northwest Province, South Africa. It has been classified as a Mississippi Valley type deposit and is, together with the Bushy Park Pb-Zn deposit and F-Pb-Zn deposits near Zeerust, the only known MVT deposit of Paleoproterozoic age. The Pering open cast mine has been operational since 1986, yielding 18 Mt at an average ore grade of 3.6 wt.% Zn and 0.6 wt.% Pb. The aim of this study is to devise a metallogenetic model by integrating core logging, petrography, fluid inclusion and stable C-0-S isotope studies. The mineralogy includes sphalerite, galena and minor chalcopyrite as ore minerals, with diagenetic pyrite, hydrothermal dolomite, quartz and calcite as gangue minerals. Sphalerite predominates over galena. Mineralisation occurs as (a) disseminated stratabound replacements sheets restricted mainly to stromatolitic zones of the Steekdorings Member of the Reivilo Formation, and as (b) open space infill in breccia bodies that cross-cut the stratigraphy. Three events of hydrothermal brecciation, resultant of prolonged pulses of fluid infiltration, and mineralisation are recognised. The first brecciation event is marked by the cementation of the dolomite host rock by sparry dolomite, closely associated with finegrained disseminated sphalerite and galena. The second brecciation event is of minor importance, and is marked by the formation of small amounts of the second sphalerite generation, while the third, and final, brecciation event is marked by the formation of euhedral sphalerite, galena, quartz, sparry dolomite, and calcite as open space fill.
| Identifer | oai:union.ndltd.org:netd.ac.za/oai:union.ndltd.org:uj/uj:1922 |
| Date | 24 January 2012 |
| Creators | Greyling, Lynette Natasha |
| Source Sets | South African National ETD Portal |
| Detected Language | English |
| Type | Thesis |
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