| The organic matter associated with the ore deposits of Gays River, Nova Scotia, Southwestern Wisconsin, and Elmwood, Tennessee, has been characterized. Comparisons have been made in the distributions of the organic species identified from unmineralized and mineralized samples, and the results interpreted with the objectives of understanding the genesis of the deposits, and considering the potential of the organic matter as an aid in prospecting.; The variations in the distributions in the organic species isolated from the three deposits reflect variations in the host rock palaeoecology, facies, and geological age. Additional were the effects of microbial degradation, thermal maturation, and water washing. Mineralization in both the Gays River and Wisconsin Deposits caused an increase in the concentrations of low molecular weight n-alkanes.; The genetic model used in this study assumes that the mineralizing brines evolved from sedimentary basins and migrated to the future host rocks for the ore. Therefore, a second, epigentic generation of organic matter must occur in the deposits. In the Gays River Deposit, the probable aquifer for the mineralizing solutions contains an organic distribution markedly different from the indigenous matter in the host reef, perhaps due to a second, epigentic organic fraction in the deposit. No clear evidence, based on hydrocarbon distributions and carbon isotopic compositions of the Wisconsin Deposit, was observed for an epigenetic organic generation. This is probably due to dilution, and masking, by the high concentration of indigenous organic material. Less likely are genetic models involving a magmatic association, reduction by the indigenous organic matter, microbial or inorganic reduction of sulphate as a local source for sulphur in the ore, and the organic material itself being a source of sulphur.; As a potential aid in prospecting, evidence was found for a thermal anomaly at the Gays River Deposit, but not at the Wisconsin Deposit. The thermal maturity of the organic matter confirms a previous estimate of 0.25 my to form a major ore body in the Wisconsin District. |
