Renosterkop is a large low grade tin-tungsten-zinc deposit located 85km WSW of Upington in the northern Cape Province, South Africa. The mineralization is hosted by a number of shallow-dipping, sheeted greisen bodies that are surrounded by, and partly intercalated with a well foliated granite gneiss country rock. The gneiss is taken to belong to the intrusive Riemvasmaak gneiss of the Namaqualand Metamorphic Complex. The mineralized host (referred to as TBQ) is a grey, homogeneous, fine to medium grained rock composed predominantly of quartz, biotite and topaz with minor amounts of fluorite and accessory opaque minerals, zircon and secondary chlorite. The unmineralized granite gneiss country rock is medium-to coarse-grained, pinkish in colour and composed primarily of microcline, plagioclase, quartz and biotite, with or without hornblende. Rock types, transitional in mineralogy but with clearly distinguishable contacts, are present between the TBQ and the granite gneiss. A prominent chemical and mineralogical halo, 20m to 50m wide, envelopes the Renosterkop deposit. There is a gradational transition from an unaltered hornblende biotite gneiss, through gneiss containing greenish-brown biotite to an approximately 2 m wide transition zone, characterized by the partial replacement of the greenish-brown biotite by chlorite. The transition zone in turn yields to the TBQ in which reddish-brown biotite forms at the expense of the chlorite, and topaz, quartz and fluorite are formed at the expense of the feldspar. Major and trace element analyses show a spectrum of chemical compositions with coherent trends that support a gradational transition from the hornblende-bearing granite gneiss, through the transitional rock types to the TBQ. The mineralogical and chemical characteristics of the Renosterkop rock types are consistent with an origin by progressive greisenization of a "within plate" A- type granitoid host rock. A genetic model is proposed which involves the formation of the TBQ greisen during intense metasomatic alteration and replacement of the granite gneiss within a zone of structural weakness that provided conduits for migrating, F-rich, metal-bearing solutions, and thereby inherited the foliation and structural features present in the original granite gneiss. / Thesis (MSc)--PU vir CHO, 1987.

Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1916. / The entire thesis text is included in file. Typescript. Illustrated by authors. Title from title screen of thesis/dissertation PDF file (viewed April 2, 2009)

Thesis--University of Missouri, School of Mines and Metallurgy, 1914. / The entire thesis text is included in file. Typescript. Illustrated by authors. Title from title screen of thesis/dissertation PDF file (viewed April 8, 2009)

Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1916. / The entire thesis text is included in file. Typescript. Illustrated by author. Title from title screen of thesis/dissertation PDF file (viewed April 30, 2009)

Thesis (Ph. D.)--University of Texas at Austin, 1998. / Vita. One folded ill. in pocket. Includes bibliographical references (leaves 222-235). Available also in a digital version from Dissertation Abstracts.

Thesis (M.S.)--University of Wisconsin--Madison, 1967. / eContent provider-neutral record in process. Description based on print version record. Includes bibliographical references.

Thesis (M.S.)--University of Missouri, School of Mines and Metallurgy, 1931. / The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed February 9, 2010) Includes bibliographical references (p. 38-39).

This thesis presents the application of the state-of-the-art processing, interpretation and modeling to the 3D reflection seismic data that were acquired between 1988 and 2003 across the West Rand and West Wits line goldfields of the Archean Witwatersrand Basin. The re-processing of the old 3D seismic data using new imaging techniques, such as 3D Kirchhoff prestack time migration (KPSTM), has led to better imaging of the ore body, structures (faults and dikes), and steeply dipping stratigraphy. Detailed interpretations of the highly auriferous Ventersdorp Contact Reef (VCR) using advanced complex seismic trace and horizon - based seismic attributes, have led to discoveries of ore blocks (~ 1 km long and ~ 250 m wide) that are bound by multi-fault segments of the first-order scale Bank and West Rand faults, leading to an increase of the resource portfolio and potentially, the quantity of the reserves. In particular, the edge detection attributes have resolved faults with throws as small as 10 m and complex structural architectures such as intersecting and cross-cutting faults, and fault bifurcations which are difficult to detect using conventional techniques (e.g., amplitude, dip and azimuth). Potential conduits, such as faults and dikes for migration of water and methane into underground workings were also mapped using edge detection attributes. These results have the potential to play into safe mine planning. The interpretation of the merged 3D seismic datasets, integrated with underground maps, boreholes, absolute and relative geochronological data, has added to our understanding of the gross structural architecture and Neoarchaean tectonic evolution of the goldfields. On a first-order scale (400 m - 2.5 km) the data resolved: (1) the northerly-trending disharmonic Libanon Anticline with a wavelength of 8 km and amplitude of 2 km, which was formed during deformation in the Umzawami Event (ca 2.73 Ga); and (2) the north-northeast trending, west-dipping (65°–70°W) listric West Rand and Bank faults, which were formed during a major extensional event, herein termed the Hlukana- Platberg Event (2.70-2.64). On a second-order scale (25 m - 400 m) the datasets resolved: (1) the Tandeka and Jabulani thrusts 1.5 km below the West Rand and Bank faults in the depth interval of 6-8 km; and (2) a series of drag synclines and rollover anticlines in the immediate footwall and hangingwall of the West Rand and Bank faults. Further to this, the seismic sections across the goldfields provided evidence that the first- and second-order scale faults, thrust and folds were dissected, eroded and overlain by the Transvaal Supergroup above an angular unconformity. The oldest approximate age for the Transvaal Supergroup is given as 2.58 Ga, thus constraining the age of the faults, thrust and folds to the Neoarchaean or pre- 2.58 Ga.

The solution geochemical conditions associated with the development of supergene copper mineralisation in the E22, E26 and E27 deposits at Northparkes, New South Wales, have been explored. Determination of a stability constant for sampleite [NaCaCu5(PO4)4Cl·5H2O], a conspicuous species in the upper oxidised zone of E26, has led to an understanding of the differences between the three deposits in terms of the influence of groundwater geochemistry on their mineralogical diversity. Modelling of copper dispersion from the three deposits using current ground water compositions as proxies for past solution conditions has shown that the elevated chloride concentrations associated with E26 have negligible influence on total dissolved copper concentrations over a wide pH range. The results are discussed with respect to applications in exploration geochemistry for the discovery of new ore deposits in the region. Determination of a stability constant for lavendulan [NaCaCu5(AsO4)4Cl·5H2O], the arsenate isomorph of sampleite, suggests that solid solution between lavendulan and sampleite is likely to be extensive and this has been established by reference to mineral compositions from a number of deposits. Activity-activity phase diagrams have been developed to explain the common mineral associates of lavendulan and differences between the analogous phosphate and arsenate systems. With respect to the occurrence of lavendulan in the oxidised zone of the Widgiemooltha 132 N ore body, Western Australia, its crystal chemistry explains why Ni does not substitute for Cu in the lattice. This is despite Ni being abundantly available in the deposit and substituting freely into other copper-based minerals. The substitution of Ni for Cu was explored in a study of supposedly Ni-rich paratacamite, Cu2Cl(OH)3, from the deposit. It transpires that much of this is a new mineral, gillardite, Cu3NiCl(OH)6, the isomorph of herbertsmithite, Cu3ZnCl(OH)6. The nature of gillardite was thoroughly investigated and the mineral was approved as a new species by the International Mineralogical Association. A high resolution single-crystal X-ray structure of gillardite has been completed. In addition, the substitution of Ni in simple carbonate lattices has been explored as gaspéite, NiCO3, Ni-rich magnesite, MgCO3, and calcite, CaCO3, are all common species in the oxidised zone of the Widgiemooltha 132 N deposit. Attention was subsequently focussed on the geochemistry of the element Bi, with special reference to deposits of the Kingsgate region, New South Wales. This study has led to a modern assessment of the Mo-Bi deposits in the area and new Bi sulfosalts from the Wolfram pipe at Kingsgate are described. A survey of secondary Bi minerals from a host of deposits has led to the development of a model for the dispersion of Bi in the supergene environment, which will have widespread applications in exploration geochemistry where Bi is used as a pathfinder element. Calculations of aqueous Bi species in equilibrium with bismite, Bi2O3, bismoclite, BiOCl, and bismutite, Bi2O2CO3, over a wide pH range show that the element is very insoluble under ambient oxidising conditions. It is noted that the results of previous geochemical exploration campaigns in the region will have to be reassessed. / Doctor of Philosophy (PhD)

Thesis (M.S.)--University of Missouri, School of Mines and Metallurgy, 1930. / The entire thesis text is included in file. Typescript. Title from title screen of thesis/dissertation PDF file (viewed January 15, 2010) Includes bibliographical references (p. 63) and index (p. 64-65).