Most of the Great Basin sediment-hosted gold deposits are located along well defined, northwest-striking trends. Trends coincide with faults, intrusive rocks and magnetic anomalies. Sedimentary host rocks are siltstone, sandstone, conglomerate, argillic, interbedded chert and shales. Silty bedded silty dolomites, limestone and carbonaceous shales are the most favourable hosts. High, and locally, low-angle faults are very important structural features related to the formation of the ore bodies. High-angle faults are conduits of hydrothermal fluids which react, shatter and prepare the favourable host rock. Decalcification, silicification, and argillization are the most common hydrothermal alteration types. Jasperoid (intense silica replacement) is a significant characteristic; not all of these deposits are gold-bearing. Most deposits contain both oxidized and unoxidized ore. Fine grained disseminated pyrite, arsenian pyrite, and carbonaceous material are the most common hosts for gold in many deposits. These deposits are also characterized by high Au/Ag ratios, notable absence of base metal and geochemical associations of Au, As, Sb, Hg, Ba and TI. Recently numerous sediment-hosted gold deposits have been recognized in different regions of the world. They vary in their size, grades, textwe, host rock lithology, degrees of structural control and chemical characteristics. However, they have many common features which are very similar to the general characteristics of sediment-hosted gold deposits in the Great Basin, U.S.A. Besides these similarities, several unusual features are recorded in some newly discovered deposits elsewhere, such as predominant fault controlled paleokarst related mineralization and the lack of two very common trace elements (Hg, TI) in Lobongan/Alason, Indonesia; and Early Proterozoic age metamorphosed host rocks and lack of Sb in Maoling, China. The discovery of the deep ores in the Post-Betze and Rabbit Canyon, Nevada, proposed sediment-hosted Au emplacement at deeper level (4 ± 2 km; Kuehn & Rose, 1995) combined with a lack of field evidence for paleowater table and paleosurface features has ruled out a shallow epithermal origin. Recent discoveries in other parts of the world throw important new light on the ongoing genetic problems. Intrusive rocks are present in nearly all sediment-hosted gold deposits. Numerous intrusion-centred districts worldwide are characterized by tWo or more different mineralization types and consequently by metal zoning. Sediment-hosted gold deposits are proposed as a distal part of intrusion-centred magmatic hydrothermal systems (Sillitoe &Bonham, 1990).

No description available.

[No abstract submitted] / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

[No abstract submitted] / Arts, Faculty of / Vancouver School of Economics / Graduate

[No abstract submitted] / Science, Faculty of / Earth, Ocean and Atmospheric Sciences, Department of / Graduate

Tyler used Hall coefficient measurements to evaluate the gold acceptor concentration in germanium crystallized from a germanium-gold melt at a temperature between the melting point of pure germanium and 17°K below this temperature. The present study reports the results of similar measurements in the temperature range of growth from 12° to 80°K below the melting point of germanium. A crystal grower was designed and constructed for growing the monocrystals of gold-doped germanium. It was found that the <100> direction was the most favorable direction for eliminating dendritic growth on gold-rich phase crystallized as inclusions. The phenomenon of retrograde solubility was observed. The maximum solubility (~2.8 x 10¹⁶ gold acceptor atoms per c.c.) occurred at about 30°K below the melting point of pure germanium. Infra-red absorption in gold-doped germanium was studied between 4.2° and 298°K over the energy range from 0.08 to 0.6 e.v. The magnitudes of the absorption cross-sections for the specimens containing about 3.5 x l0¹⁵ and 1.2 x 10¹⁵ gold acceptor atoms per c.c. were in close agreement with the data of Johnson and Levinstein. The cross-section of absorption near the band gap of germanium for the heavily gold-doped germanium ( ≻ 10¹⁶ gold acceptor atoms per c.c.) is about the same as in the case of lightly doped specimens. Whereas in the case of lightly doped specimens, however, the cross-section of absorption drops sharply to negligible values as the energy of the incident photon decreases, the cross-section of absorption for the heavily doped specimen remains very high. The excess absorption is found to remain substantially the same when measurements are extended to the energy range between 0.032 and 0.044 e.v. At 298°K, the absorption of infra-red radiation in gold-doped germanium shows spectral structure associated with valence band intra-band transitions. For the lightly doped specimens, with increasing concentration, the structure in the spectrum becomes less pronounced. Newman and Tyler have reported studies of the same effect in gallium-doped germanium. Our studies indicate that the effect is more pronounced in gold-doped germanium than in gallium-doped germanium. When intra-band absorption is peeled off from the absorption spectra at 195° and 298°K, the threshold of absorption is at a higher energy for the higher temperatures. The transmission of infra-red light through both pure and lightly gold-doped germanium is found to be enhanced by about 16 per cent at 4.2°K compared to that at higher temperatures (≻60° K). The determination of surface reflectivity at 4.2°K gives 0.29 and correspondingly a refractive index (μ) of 3.3 This shows an anomalous behaviour of {equation omitted} at low temperatures. It is known that materials with the diamond structure reveal similar extraordinary behaviour in other lattice properties such as the temperature dependence of their coefficient of thermal expansion and Debye temperatures. / Science, Faculty of / Physics and Astronomy, Department of / Graduate

An investigation was conducted of the corrosion of copper-gold alloys in ammonia solutions under oxygen pressure. The reaction, which took place in an autoclave, was followed by sampling and analysis of the solutions. It was found that only copper was dissolved from the alloys, the gold being left behind in a film on the surface of the corroding specimen. The reaction of pure copper as well as of four alloys ranging in gold content from 2 to 15 atomic percent were studied. Other variables examined include the concentrations of NH₃ and NH⁺₄ in the solution, the oxygen pressure and the temperature. It was found that while the rate curves for the dissolution of pure copper were linear, those for the alloys were generally parabolic in shape. The rate of dissolution of copper from the alloys appears to be determined by the transport of reactants and products through the gold rich films. Some copper oxide may also be precipitated in the pores of the film or in the region between the film and the underlying metal, further impeding the transport processes and contributing to the lowering of the rate. / Applied Science, Faculty of / Materials Engineering, Department of / Graduate

[No abstract submitted] / Arts, Faculty of / History, Department of / Graduate

The thesis sets out to determine the causes of the gold hoarding and dishoarding in Argentina between 1900 and 1914. It was found that gold (dis)hoarding was part of a mechanism whereby the money supply was altered to meet demand through the exchange of gold pesos for paper. Speculation was important only in late 1913 and 1914 when the possibility emerged that paper would become inconvertible, the price of gold would rise and capital gains would accrue to gold holders. Five assumptions were made: (1) that the money supply was a function of the gold stock, (2) that the demand for money was a function of the level of income, (3) that the Neoclassical explanation of the determination of income fitted Argentina during this period, (4) that price and money income levels were given on world markets, and, (5) that the level of exports determined the level of income. In Argentina during the period 1900 - 1914, gold served two functions: (1) it provided the money supply, and (2) it balanced the international accounts. The thesis argues that although Argentinians were constrained by fixed levels of prices and income and by the rules of the gold standard they were able to alter the real supply of domestic currency by (dis)hoarding gold from their private stocks. Hoarding was found to be correlated with the velocity of money. Consequently it is argued that gold was used to adjust the money supply toward the level of income regardless of what the level of income was. Gold was also found to be correlated with income, although less highly than with velocity. Consequently gold tended to be dishoarded in years after a good spring crop when paper was needed to buy land and real estate and to expand production. In this way gold acted as a precautionary asset which could be used to make advantageous purchases and which was secure in value, the two criterion suggested by Keynes. However, gold behaved in the opposite way to the precautionary balance described by Friedman who felt that the asset would be dishoarded when income was low. Other possible determinants of gold (dis)hoarding were tested and rejected. Two proxies for the interest rate, railroad receipts, and the note issue (the money supply) were correlated with gold (dis)hoarding but the coefficients were not significant. The thesis also suggested that the definition of balance of payments equilibrium should allow for a persistent gold import which would provide a domestic money supply. In equilibrium the rate of gold import equals the rate of growth of income if a constant velocity of money is desired. A second subconclusion was that the international import of gold responded to demands for reserves made by the countries doing the trading. Although these demands were satisfied in the long run, they were not satisfied in the short run, and gold (dis)hoarding took place / Arts, Faculty of / Vancouver School of Economics / Graduate

The development of resources has always been one of the important factors of Canadian economy. As Canada's resource and industrial frontier extends further to the north, lasting and self-sufficient communities have become increasingly difficult to create. The first settlements were not permanent and the inhabitants' needs and demands were limited. With time needs and demands evolved and became more complex in nature. The evolution of such settlements from camps, through company towns, to incorporated towns can be traced in terms of these demands and needs. Instant resource towns, unlike, camps or company towns, are the result of a rather complicated planning process. The goal formulation of this process is much more complex, involving many external factors. Goal specification, especially where explicit goals are concerned, becomes not only a function of the criteria set, or the needs of the inhabitants, but also of the different needs and interests of each of the individual planning and policy making bodies. The purpose of this thesis is to examine the process involved in the creation of Gold River, an instant town. The planning and building processes will be examined in order to determine the discrepancies between the goals specified, both, explicit and implicit, in the planning process and the final product. The aim of the study is, therefore, to analyse the different circumstances and factors that lead to the creation of Gold River and the philosophy of the different people who contributed to it. The planning process, concerned specifically with Gold River, is analysed. An attempt is made to differenciate between the different explicit and implicit goals of each of the individual planning bodies involved. Through the analysis of this process, both, positive and negative results are studied. The method of study consists of a comparison of goals expressed in the planning process, by the different bodies interested, with the results achieved. Such comparison will allow the author to determine to what extent some of the goals have been achieved and will show how the performance of the physical environment relates to the expectations. The study is based on the results of a questionnaire gathered on a field trip to the town. The goals of the different planning bodies were determined by interviewing the parties concerned and by analysing published pamphlets concerning Gold River development. The study also describes Gold River in its different aspects as the author saw it from direct observation and from information obtained from other sources. Furthermore, an evaluation of the physical, economic and social aspects of the town in terms of user satisfaction or dissatisfaction was derived from the questionnaire. The analysis and evaluation of achievements reveals some of the causes of user dissatisfaction, high population turnover and instability to be inherent in the planning process. Achievements are considered from the point of view of both: the different planning bodies and the inhabitants. The conclusions support the hypotheses that: - Discrepancies between the inhabitants' expectations of the town and the actual reality have profound social implications. - Goal misinterpretation and partial realization is due to lack of communication between the different bodies involved in the planning process. - In the planning process goals should be expressed explicitly and clearly. The study has also shown that the problem of isolation, lack of diversity, population turnover and, lack of growth, which plagued resource towns in the past, still are major problems in the incorporated, ultramodern, instant town of Gold River. This indicates that in the planning for such towns: - The size and density of the community should be taken into consideration. - Growth and diversification of industries, as factors necessary to make a place lasting and livable, should be kept in mind. - It should be emphasized that the stability of a community is a function of the population turnover. - It is necessary to provide for substantial recreational facilities. The phenomenon of Instant towns is a recent innovation in this province and should be better understood and thus improved. This study is an attempt to contribute to a better understanding of the factors involved in the creation of such a town and therefore may be instrumental in the creation of other, better towns. / Applied Science, Faculty of / Architecture and Landscape Architecture (SALA), School of / Graduate