A dissertation submitted to the Faculty of Science, University of the Witwatersrand, Johannesburg, in fulfilment of the requirements for the degree of Master of Science. Johannesburg, December, 2013. / The Palaeoproterozoic southern Goren volcano-sedimentary belt of northeast Burkina Faso represents a sequence/package of rocks formed in a back-arc basin environment. Evidence is based on a conformable sequence of basalts that have geochemical affinities of normal mid-oceanic ridge style basalts (N-MORB) as well as arc-related magmas. Tholeiitic compositions, determined by major and trace element geochemistry, are exclusive to the study area, which is unique to northeast Burkina Faso. Flat, chondrite-normalised REE patterns suggest dominantly N-MORB compositions, with the occasional elevated Th and Al2O3 values, suggestive of arc basalts. Depleted chondrite-normalised concentrations of phosphorus (0.5-0.03 times lower than chondrite) and Ti (1-5 times chondrite) as well as anomalous concentrations of N-MORB-normalised Ta (80-120 times greater) are characteristic of the tholeiitic basalts of the Goren belt. The volcanic rocks are intercalated with a succession of volcanogenic manganese deposits, siltstone, volcaniclastite, volcanogenic greywacke and a discrete pyroclastic breccia deposit composed of lapilli- to bomb-sized volcanic debris, indicative of bimodal volcanism. The volcanic facies were established through field and petrographic interpretations. The subaqueous facies architecture consists of proximal, coherent and autoclastic basaltic flow units containing porphyritic, aphyric, amygdaloidal and hyaloclastic textures as well as pillowed, jointed and flow-banded basaltic lithofacies. Proximal to distal volcanogenic manganese deposits intercalated with basalt flows indicate a syn-volcanic genesis. A discrete pyroclastic interbed (~300 m thick) within a volcanogenic, marginal marine to offshore greywacke succession occupies a distal facies relative to the volcanic source and indicates a bimodal source of volcanism, i.e., mafic and intermediate. Volcanogenic manganese deposits are characterized by quartz-ankerite stockwork breccia, a braunite-ilmenite-magnetite-chalcopyrite-pyrite-(gold) mineral assemblage and increased Ba concentrations, indicating syn-volcanic seafloor-related hydrothermal activity. The Goren volcano-sedimentary belt presents potential for economic mineralisation in volcanogenic primary manganese and base metal deposits.

Thesis (M. Sc.), Memorial University of Newfoundland, 1998. / Bibliography: leaves 116-125. Also available online.

Thesis (Ph. D.)--University of Hong Kong, 2010. / Includes bibliographical references (leaves 179-192). Also available in print.

Thesis (Ph.D.)--University of Western Australia, 2005.

Studies of the metallogeny of northwestern Mexico (Baja California to Chihuahua to Durango) at the mining district, geologic province, and regional scale, show that deposit formation and preservation is an intricate interrelationship between magmatism, tectonism, and hydrothermal activity. These are not only complicated by superimposed factors including erosion, enrichment, and cover, but in northern Mexico, tectonic translation as well. Using palinspastic reconstructions the relative positions of geologic units are restored to their pre-extensional configuration. Metallic "belts" are heterogeneous with numerous metal associations and deposit types superimposed in the same area. The reconstructions show that magmatism and mineralization were coeval and coincident. Superimposed environments and processes cover, erode, enrich, and preserve mineralization thus substantially affecting perceived metal distribution. Cover sequences including mid-Tertiary ignimbrites and late Tertiary clastic sediments preserve and commonly conceal mineralization. Mid-Tertiary and older extensional events preserve near surface deposit types (e.g, supergene blankets, Jurassic rift-related deposits). At the Sierra Madre Occidental (SMO) province scale, ore deposit types exhibit enormous variation from adularia sericite-dominated to advanced argillic to closely pluton related. The advanced argillic alteration with gold+/-copper+/-silver deposit types appears related to magmatic centers occurring in both the older (pre-Oligocene) and younger (Oligocene) volcanic sections and is a major focus of this dissertation. Acidic alteration-related deposits make up some of the largest Au occurrences including the Mulatos >2 million ounce gold district. Extensive kaolinitic alteration halos (>8 km²) zoned around a core of vuggy silica and quartz+/-pyrophyllite host enargite-pyrite ores. Sulfide isotopes are near zero δ³⁴S(pyrite) = -5 to -3%; δ³⁴S(enargite) = -6 to -4%) with corresponding barite (δ³⁴S = +18-22%). Phase equilibria and isotopes indicate early pyrophyllite-pyrite ores formed at ∼ 300°C with later barite-pyrite-dickite ores deposited at T = ∼ 260°C. Oxygen and hydrogen isotopes show possible mixing between magmatic and meteoric waters with a late (shallow) meteoric (heavier D, lighter δ¹⁸O) overprint. District tilting (∼ 25°NE) exposes >1.5 km altered section containing two separate centers. Alunite occurs late, rarely and is above pyrophyllite, suggesting a vertical transition in acid sulfate systems.

Thesis (M.Sc.)--Memorial University of Newfoundland, 2002. / Bibliography: leaves R-1-R-17. Also available online.

Cerro Rico is the world's largest silver deposit. Hypogene mineralisation is hosted by a sheeted, polymetallic vein system which cross-cuts a pervasively altered rhyodacite dome. The 13.8Ma dome was intruded along a regional dextral strike-slip fault. Subsequent movement focused stress within the dome, creating a closely-spaced fracture system, best described as an extensional duplex. Hydrothermal alteration shows features characteristic of both porphyry and epithermal deposits. Shallow acid-sulphate alteration, comprising sub-horizontal zones of advanced argillic alteration and residual vuggy silica, formed through the neutralisation of a supergene, acid-sulphate fluid derived from the atmospheric oxidation of hypogene H₂S. Deep sericitisation which largely pre-dates the polymetallic vein mineralisation is the product of wall-rock reaction with magmatically-derived volatiles. Localised tourmalinisation resulted from the violent release of boron-rich fluids during early decompression events. A buried magma body is implied for the source of volatiles. Polymetallic vein mineralisation is vertically and laterally zoned from deep Sn-W-Bi-As-Cu assemblages to peripheral Pb-Zn-Sb-Ag. Hypogene silver occurs within complex Pb-Sb sulphosalts, tetrahedrite (freibergite), pyrargyrite and argentite. Mixing of reduced, near-neutral, hypogene Ag-bearing fluids and oxidised, supergene, acid-sulphate fluids caused the precipitation of 'bonanza' silver mineralisation within the acid-sulphate lithocap. Early pre-mineral fluids were hypersaline (34wt. %NaCl equivalent). Main stage ore fluids varied in temperature between 140 and 410°C with salinities averaging 11wt.% NaCl equivalent. Stable isotope data are consistent with a magmatic source both for the ore fluid and sulphur. Following collapse of the hydrothermal system, a fall in the palaeo-water table caused deep oxidation. Silver was released from hypogene sulphosalts and re-precipitated as disseminated acanthite and silver halides. Hypogene Ag₂S remained stable in the weathering environment. The oxide zone, preserved by a semi-arid climate, currently constitutes a world-class silver orebody.

Mémoire (M.Sc. A.)--Université du Québec à Chicoutimi, 1984. / "Mémoire présenté en vue de l'obtention d'un diplôme de M.Sc.A. (géologie)" CaQCU Bibliogr.: f. 129-133. Document électronique également accessible en format PDF. CaQCU

Thèse (Ph.D.R.M.)-- Université du Québec à Chicoutimi, 1992. / Résumé disponible sur Internet. CaQCU Bibliogr.: f. 187-204. Document électronique également accessible en format PDF. CaQCU

Thèse (D.R.M.)--Université du Québec à Montréal, 1999. / Document électronique également accessible en format PDF. CaQCU