A STUDY OF THE PICHE GROUP AND VEIN SYSTEMS AT DARIUS MINE, CADILLAC, QUEBEC

The gold mineralisation at Darius Mine, Cadillac Quebec, is associated with quartz veins within the rocks of the Piché group. The Piché group consists of both volcanic and sedimentary rocks, older than 2.68 Ga, which crop out along the southern side of the Cadillac break at the interface between the flyschoid sedimentary rocks of the Pontiac group to the south and the volcano-sedimentarv succession of the Abitibi belt to the north. The Cadillac break probably represents an ancestral fault zone along which movement occurred during the deposition of the adjacent Archean rocks. The evolution of the Piché group has been influenced by both Pontiac group sedimentation and Abitibi belt volcanism. It consists of three cycles each of which comprises distinctive volcanic and sedimentary rocks. In the first cycle mafic tholeiitic lavas and tuffs conformably overly the Pontiac grouo grevwackes. Subvolcanic andesite sheets and lenses of qrevwacke occur within the mafic extrusive rocks which are overlavn bv a thin but persistent conglomerate unit. This is interpreted as having been deposited by a mass flow of unconsolidated sediment. The second cycle consists of a unit of calc- alkaline pillowed andesite flows in which auriferous pvrit- ic cherts are developed locally in the pillow interstices and on the upper contact of the unit. Overlying the andesite unit is a thin lens of siliceous greywacke which, ii 1 in part, consists of andesitic tuffaceous material. This is overlavn by an epiclastic biotite grevwacke at the top of the second cycle. The third cycle is composed of intercalated units of mafic tholeiitic tuffs, lavas and sub- volcanic intrusions and volcaniclastic and epiclastic greywackes. Lenses of pyritic chert and carbonaceous argillite are developed on the contacts of the various members of the cycle. In the north the rocks of the third cycle abut against the ankerite talc-chlorite schists of the Cadillac break. Previously it has been considered that the gold and quartz in the veins was deposited by metasomatic fluids. This study however indicates that two stages of mineralisation have occurred. In the first stage of mineralisation, which is considered to be syngenetic, gold mineralisation is associated with pyritic cherts which are developed as interflow sedimentary rocks and are characterised by a relative enrichment of Cu and Zn and depletion of Cr and As. Here it is suggested that gold was precipitated with chert and sulphides from hydrothermal fluids discharged on to the sea floor during the volcanism of the second and third cycles. The gold quartz veins of the second stage of mineralisation transect the rocks of the Piche group at low angles and are considered to have been emplaced subsequent to the deposition of the Piche group rocks, and are therefore epigenetic. The veins are characterised by a relative enrichment of Cr and As and a IV depletion of Cu and Zn and are commonly surrounded by a potassic alteration zone. It is suggested that the gold and cruartz were deposited in dilatent openings within the rocks of the Piche group from ascending hydrothermal fluids generated at depth by dehydration reactions during prograde regional metamorphism. It is probable that the ore shoots represent the principal channels for the ascent of fluids. Where the veins are developed adjacent to the auriferous pyritic cherts of the first stage of mineralisation it is possible that gold was remobilised and concentrated in the veins

An investigation into the effects that internet user experience, payment reliability and delivery reliability have on e-Commerce use in South Africa

This research investigates the extent of retail e-commerce use in South Africa with respect to the reliability of payments and the delivery system. This is aligned to the consumer’s internet experience. The Technology Acceptance Model and e-Service Quality Model provide a framework for this research. This investigation has focussed on the use of e-commerce through various distribution channels, such as services (e-Tickets or flights), delivered goods, downloaded media and auction sites. This quantitative research was conducted through a survey of internet users (within LSM 9 and 10) and the findings compared the respondents’ internet experience with their use of e-commerce. It was found that e-commerce adoption is related to the years of internet use and degree of internet utilisation. Furthermore, the amount spent by consumers through the internet increases with more frequent e-commerce use. The findings also reveal that a high proportion of respondents were tentative, to some degree, about online payments. In addition, the delivery of items through the postal services was considered to be unreliable, compared to courier services that were perceived to be reliable. These factors align with previous research and have an influence over the acceptance and growth of e-commerce in South Africa. CopyrightDissertation (MBA)--University of Pretoria, 2010.Gordon Institute of Business Science (GIBS)unrestricte

The relationship between South

MBA - WBSThe volatility of a share or market is used as a proxy for risk in a number of financial calculations. Volatility measures the deviation from the average value, and is therefore an estimate of how much a share or market moves up and down. It is therefore measured as the standard deviation, or the square root of the variance of a time series. Understanding time-varying volatility of the South African stock and bond market, as well as that of the US stock market, is of interest to fund managers, and can have an effect on portfolio selection. The background to the individual markets, volatility in general, and findings of volatility of other stock and bond markets are discussed. Volatility of one market is described as having an influence on another market, through what is termed volatility transmission. Therefore a time-varying covariance between the markets can be determined, which assists in the description of the relationship between the respective markets’ volatility. This research describes the relationship between the volatility of the South African stock and bond market and the US stock market, through determination of a timevarying variance-covariance matrix of the markets. This is performed through the framework of a GARCH(1,1) model with BEKK representation for the variancecovariance matrix (Engle and Kroner 1995). Further restrictions are placed on elements of the model to allow empirical determination of causality in variance in one direction at a time, for example from stock to bond market, and from bond to stock market. The relationship is therefore determined within a framework that allows for prediction of the variance and covariance conditional on previous existing information. Results from this research indicate that the South African stock, bond and US stock markets are highly persistent on themselves. Results further indicate that volatility is transmitted in a unidirectional manner from the South African stock market to the South African bond market. The influence of volatility transmission is seen from the volatility persistence value, or the previous days’ stock market volatility, causing a negative influence on the current day’s bond market variance level. There is no significant influence of the South African bond market volatility on the volatility of the stock market. iii There is no evidence of a volatility relationship between the South African bond market and the US stock market. The US stock market, however, is determined to have a bidirectional volatility transmission relationship with the South African stock market. The volatility is transmitted through shocks in one market influencing the volatility of the other market, as well as through changes in the persistence of one market influencing the volatility of the other market. The US stock market is identified as the dominant partner in the relationship, as the magnitude of the volatility transmission from the US stock market to the South African stock market is larger than the volatility linkage in the opposite direction