A dissertation submitted to the Faculty of Science, University of the Witwatersrand Johannesburg in partial fulfilment of the requirements for the degree of Master of Science. Johannesburg, 2013. / Artisanal and small-scale mining (ASM) has been a crucial industry in Africa for centuries. In Burkina Faso approximately 95 kms northeast of the capital city Ouagadougou near the village of Dem and on a ferricrete capped ridge to the west of the village, it is possible to find a number of opencast workings and underground mines that show evidence of extensive artisanal mining for iron. Iron mining worked quartz-vein hosted and lateritic ore. Nearby, waste piles, processing sites and at least eleven (11) Bloomery furnaces are exposed on the alluvial plain. Petrographically the ore bearing rocks consist of goethite-hematite as the dominant oxides with silica. Geological and ethnographic studies conducted in 2011 focussed on detailing and mapping the mine site and host rocks (including ore rocks), and establishing the age of mining, processing and forging of ore. Selected charcoal samples were collected from furnaces sites. Limited AMS radiocarbon dating of six (6) samples was performed at Beta Analytic laboratory in Miami, Florida, USA and suggested that iron forging may have begun in the 15th century, which could also be the age of mining and processing of ore. The site has characteristics such as impure slag, eleven (11) large furnaces, hundreds of tuyeres, and crucibles, and clay fragments. Remnant slag samples were collected for petrographic and mineralogical study to deduce the mineral composition of the slag. The slag samples contained high concentration of fayalite, quartz, magnetite and hematite and low concentration of iron metal and ulvospinel suggesting an iron silicate slag of low melt temperature was formed in the furnaces.

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

The Hekou Group in the Kangdian region, SW Yangtze Block is a metavolcanic-metasedimentary succession hosting the giant Lala Fe-Cu-(Mo, REE) deposit. Mafic volcanic rocks of the Hekou Group and nearby gabbroic intrusions have identical zircon U-Pb ages of ~1700 Ma. The sedimentary and mafic rocks are suggested to have formed in an intra-continental rift, similar to those of the North Australian Craton. Such a similarity suggests that the Yangtze Block was likely linked with the North Australian Craton in the Columbia supercontinent during late Paleoproterozoic. Overlying the Hekou Group is a thick sedimentary sequence of the Julin Group containing basaltic layers with zircon U-Pb ages of ~1050 Ma. The basalts and other coeval igneous rocks in the region have geochemical affinity of within-plate rocks, representing a ~1.05-1.1 Ga rifting event. Occurrence of the within-plate rocks does not support existence of a Grenvillian orogenic belt in the region, and thus agrues against previous hypothesis that proposed the Yangtze Block to be located in the interior of the Rodinia supercontinent on the basis of the so-called Grenvillian orogenic belt. The Lala deposit contains 200 Mt of ores with an average grade of 13 wt.% Fe, 0.92 wt.% Cu, 0.018 wt.% Mo, 0.022 wt.% Co, 0.25 wt.% REE2O3 and 0.16 ppm Au, and is one of the largest IOCG deposits in the region. The ores are hosted mostly in meta-vocalnic rocks (albitite) and schists, and are characterized by abundant low-Ti magnetite with subordinate chalcopyrite, pyrite, molybdenite and REE minerals. The paragenetic sequence includes Stage I of Na-alteration, Stage II of Fe mineralization, Stage III of Cu-Mo-REE mineralization, Stage IV of chalcopyrite-pyrite-calcite veins and Stage V of hematite-calcite-quartz veins. Molybdenite of Stage III has a Re-Os isotopic age of 1086 ± 8 Ma, similar to U-Pb ages of the primary allanite as 1067 ± 41 Ma, suggesting that mineralization of the Lala deposit is coeval with the ~1.05-1.1 Ga within-plate magmatism in the region. The secondary allanite has U-Pb ages of 880-850 Ma, comparable to Ar-Ar and Pb-Pb ages of undeformed Stage IV and V veins, representing a younger hydrothermal event. C-O-S isotopes suggest that the Fe and Cu mineralization stages (II and III) at Lala have formed from high temperature magmatic-hydrothermal fluids (385-430ºC). However, compositions of fluid inclusions and minerals demonstrate that the Fe and Cu mineralizing fluids have different compositions. Strontium isotopic compositions of apatite and calcite suggest that the Fe mineralizing fluid has formed from magmatic fluids interacted with late Paleoproterozoic host rocks, whereas the Cu mineralizing fluid with much higher 87Sr/86Sr ratios has possibly involved magmatic fluids that have interacted with older basement beneath. Close association of monazite-bearing apatite, Cu-sulfides and REE-minerals at Lala suggests that REE mobilization and mineralization is genetically related to the Cu mineralizing fluid. This study suggests that the Cu mineralizing fluid contains Cl-, K, CO2, F-, PO43- and CO32- with low Na activity, and is thus responsible for mobilization, transportation and deposition of LREEs in the Lala deposit. / published_or_final_version / Earth Sciences / Doctoral / Doctor of Philosophy

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Thesis (Ph. D.)--University of New South Wales, 2005. / Also available online.

Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1902. / C. E. Martinez determined to be Carlos E. Martinez from "1874-1999 MSM-UMR Alumni Directory". The entire thesis text is included in file. Typescript. Illustrated by authors. Title from title screen of thesis/dissertation PDF file (viewed October 29, 2008)

Thesis (B.S.)--University of Missouri, School of Mines and Metallurgy, 1900. / The entire thesis text is included in file. Typescript. Illustrated by authors. Degree awarded only to Isaac Peter Frazier. Title from title screen of thesis/dissertation PDF file (viewed )

Thesis (M.Sc.) - Carleton University, 2002. / Accompanying material: 2 maps in pocket. Includes bibliographical references (p. 119-127). Also available in electronic format on the Internet.