Thèse-Neuchâtel. / "Bibliographie": p. [305]-310.

Thesis (doctoral)--Uppsala universitet, 1783. / Reproduction of original from Kress Library of Business and Economics, Harvard University. Goldsmiths'-Kress no. 12400.1-3.

Thesis (Ph.D.)--York University, 2004. Graduate Programme in Environmental Studies. / Typescript. Includes bibliographical references (leaves 251-262). Also available on the Internet. MODE OF ACCESS via web browser by entering the following URL: http://wwwlib.umi.com/cr/yorku/fullcit?pNR11556

The Mitchell-Sulphurets region is in the heart of the Coast Mountains of northwest British Columbia. Geologically it is situated on the western edge of the Bowser basin approximately 12 miles east of the main Coast Mountains plutonic complex. The map-area is underlain by partly or wholly metasomatized sedimentary, volcanic, and intrusive rocks. The volcanic and sedimentary rocks are tentatively dated as Lower Jurassic. They probably belong to Lower Hazelton and/or possibly Upper Takla group. The sediments are typical of a greywacke, turbidite suite. The volcanics belong to a marine sequence chiefly comprising pyroclastic members. Possibly in Jurassic time, the sedimentary and volcanic rocks of the area were invaded by the Mitchell Intrusions. The earlier members of the Mitchell Intrusions were injected as sills and dykes predominantly into the well-bedded sediments. The later members formed larger, more irregular bodies. There are marked mineralogical changes within the intrusions. Differentiation by fractional crystallization and composite intrusion account for original variations in mineral composition, but post-crystallization changes are the cause of unusual rock types. Spilitized diabase, syenodiorite, albite syenite, syenite, quartz syenite, and some granite have resulted from the "deliming" or albitization of the original plagioclases. Immense quantities of trapped volatiles, which were concentrated by differentiation processes, resulted in phenomenal amounts of rock alteration during the dying stages of the magmatic period. They have had a profound effect on an area of rock about three times that of the intrusions. During the period of rock alteration the area approached an equilibrium environment probably somewhere below 400° C. and probably at moderate pressures. Throughout the area altering fluids probably contained moderate concentrations of Na, K, SiO₂, and H₂S, high concentrations of CO₂ and H₂0, and in the Mitchell Valley trace amounts of HF. The end of the alteration period was sharp, possibly being terminated by the development of major faults which could have permitted the release of the fluids. The chief types of alteration - albitization, carbonatization, sericitization, silicification, chloritization, and pyritization - have affected the rocks in a similar manner throughout most of the area. In most areas secondary minerals in highly altered rocks are the same as those in the slightly altered rocks. The mineral deposits, which are of the "Porphyry Copper" type, were formed during the alteration period. The presence of large volumes of volatiles at an elevated temperature allowed extensive migration of the metal-bearing solutions from their magmatic source. Disseminated dopper and molybdenum mineralization is found in porphyritic, granitic intrusions and in altered volcanic, sedimentary, and intrusive rocks. The large quantities of fluids have also resulted in the separation of the copper and molybdenum sulphides into distinct deposits. The formation of distinct deposits was probably dependent upon the physical-chemical properties of the environment at the time of alteration. Major faulting occurred late in the alteration period. This marked the end of the Mitchell epoch of magmatic activity. Somewhat later in the history of the area, possibly in Tertiary time, a few keratophyre (basaltic (?)) dykes were emplaced. Extensive erosion by glaciers in Pleistocene and Recent times has sculptured the landforms into their present shapes. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

An approach pioneered by M. Allais in his evaluation of the exploration potential of the Algerian Sahara has been applied to the evaluation of a very much smaller region. The region investigated is a two square mile area, termed the "exploration area", situated in the silver-lead-zinc Sandon mining camp, Slocan Mining Division, British Columbia. Although virtually unprospected because of overburden cover, the exploration area appears to be as favourable to ore deposition as the adjacent parts of the camp. In order to estimate the mineral deposit distribution in the area a count of mineral deposits in adjacent parts of the camp has been undertaken. The mineral deposits in these parts were counted from an examination of geological maps. The counted distribution may be regarded as a sample of the deposit distribution in the Sandon camp, including the exploration area. The true distribution in the camp may be assumed with a high degree of probability to lie within the 95 per cent confidence interval of a Poisson distribution representing the sample distribution. The observed distribution and the upper and lower confidence limits define three estimates of the number of deposits existing in the exploration area. These estimates may therefore be said to represent three approximations of the situation in the exploration area. These approximations have "been termed the mean, low and high models, respectively. Value of the mines likely to exist has been obtained from a study of the frequency distribution of 14 Slocan mines. The gross value of recoverable metal content (referred to as gross value) for the median mine in this distribution was taken to represent the most probable gross value of a discovered mine. Resultant discovery probability for the mines, important prospects, prospects, and showings postulated to exist in the exploration area has been estimated at 0.45, 0.45> 0.35 and 0.3 > respectively. The effect of variations in these estimates has been investigated. The cost of exploration has been calculated for each model, envisioning a program to explore the area in stages. Costs are largely a function of the number of deposits existing, uncovered and examined. The merits of the exploration venture have been measured for each model by comparing exploration costs with the expectation (present value of all mines in a model multiplied by the probability of finding them). Using the assumed value of both mines and resultant discovery probability, the venture appeared marginal when measured against a minimum acceptable return of 150 per cent. Comparison of cost vs. expectation using lower estimates of these two parameters indicated that the venture is not economic. However, considering the essentially marginal nature of the venture a $6,500 expenditure to gather more detailed information for a revaluation is warranted. Thus Allais's approach to evaluation has been found to give a realistic and useful quantitative appraisal of the exploration area. / Applied Science, Faculty of / Mining Engineering, Keevil Institute of / Graduate

Slocan City mineral deposits are "dry" fissure types (Cairnes, 1934, p.114) consisting of high grade silver veins in quartz, with minor amounts of lead and zinc. These veins, almost all in Nelson plutonic rocks, occur in an area of approximately 100 square miles along the eastern margin of Slocan Lake. Mineralogical analysis revealed a definite concentric zoning in the camp; a pyrite halo with high gold values surrounds a core of galena and sphalerite with high silver values. The most commonly occurring minerals in order of deposition are: pyrite, sphalerite, chalcopyrite, gold, tetrahedrite, galena, silver, ruby silvers, and argentite. Quartz is the dominant gangue mineral, with small amounts of calcite, siderite, barite, and fluorite generally concentrated in the central zone. Publically available production data for 73 mineral deposits, and geological and mineralogical data obtained from field and laboratory studies,were organized in a computer-processible data file. Methods used to investigate the usefulness of such a file for both academic and practical purposes include: computer generated plots and contour maps, correlation studies, trend surface analysis, multiple regression, and chi square analysis. Computer contour plots and trend surface analysis were rapid means of analyzing lateral zoning of average metal grades and ratios. Patterns obtained substantiated the mineral zoning which was based on data from appreciably fewer mineral deposits. Multiple stepwise regression showed that value of a deposit (estimated by total production in tons) is dependent on average grades of lead and zinc, and volume percentage total sulphides. Consequently, the tonnage potential of a prospect might be predictable within specified limits from a single bulk sample and a brief geological examination. Chi square analysis showed that relatively large deposits are characterized by a more-or-less northeasterly strike and the presence of small amounts of barite and carbonate gangue. The ease and rapidity with which proven statistical techniques can be applied to the mass of informal ion in a computer-processible data file gives great scope and practicality to the concept. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

The study area is characterized by complex terrane encompassing the junction of three major tectonic belts: the Coast Plutonic Belt, the Intermontane Belt, and the Cascade Belt. Examination of the detailed tectonic framework was facilitated by the construction of a time-space plot which illustrates the salient features of the six small-scale tectonic belts within the area. Subsequent examination of metal deposits was facilitated by the MINDEP inventory file which supplied location and reference information. Detailed descriptive information on metal deposits was categorized and tabulated with respect to metals, deposit type, host rock formation and host rock type. This data was then integrated into the tectonic framework to outline a metallogenic model for the area. A simplistic model for the evolution of the major features in the area involves eugeosynclinal and trench-like deposition from Upper Paleozoic until Jurassic-Cretaceous time when the developing Coast volcanic and plutonic arc collided with the established Intermontane arc on the east. Arc volcanism in the Coast Plutonic Belt produced the initial volcanogenic metal sulfide accumulations in the area which subsequently were remobilized into adjacent areas during collision. The axis of collision contains a major magmatic sulfide deposit which probably formed at this time as a result of collision. Significant mineralization is found also west of the collision axis near the deep-seated Hozameen fault along which gold-rich fluids have formed veins near serpentine bodies. Similarly, a large disseminated gold deposit occurs in slate adjacent to the Hozameen fault in the area of major vein mineralization. Subduction responsible for the Tertiary episode of plutonism and volcanism centered in the Cascade Belt also produced small skarn, vein and porphyry deposits during a subsequent episode of remobilization mineralization. / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

A Project Report submitted to the Faculty of Engineering and the Built Environment, University of the Witwatersrand, Johannesburg, in partial fulfillment of the requirements for the degree of Master of Science in Engineering. Phalaborwa, 24 May 2018 / The renowned PMC’s copper open pit operation transitioned from surface copper operations to an underground operation in 2002. An exploration shaft from within the open pit, having an exploration tunnel below the open pit bottom served ideally for downward resource exploration drilling. Palabora Underground Mining Project was a first to cave in very competent lithology rock types which utilised the crinkle cut method at its undercut level. Unfortunately, the inadequate underground exploration drilling limited the resource classification and confidence levels, having inadequate drilling to represent the vast footprint block cave area. Consequently, the head grade and the modelled grade required annual revisions. The head grade and modelled grades diverted from each other more than once, despite all the numerous studies with minor and significant model improvements. The block model refinements included adjustments made to the block sizes, draw column alignments with blocks and additions such as the dolerite dilution representation within blocks. The resource model revision pointed firstly to the grade change between the mill grades and predicted modelled grade, and secondly to the identified geometric change and rectification thereof. Significant technical studies refined the resource model to satisfactory levels of confidence. However, the elusive cave behaviour encouraged more studies and refinements as new information became available over time. The copper open pit’s north wall failure occurred in 2004, and this failure material contributed to significant resource losses. The importance of the many approaches and models which predicted or assumed the possible block cave’s life after the failure characterises the PMC block cave uniquely. Some of the significant studies over time, encapsulated in this project report sketch a realistic timeline of the copper block cave at Palabora Mining Company. The initial resource losses became somewhat redeemed during the 2015 study where some of the copper gains were within the failure’s glacial flow, and not from the likely toppling effect which injected some additional years to the life of mine. / MT 2018

No description available.

Thesis (M.Eng.(Mining Engineering))--University of Pretoria, 2000. / Abstract in English. Includes bibliographical references.