Oxygen and carbon isotopes in ore deposits in sedimentary rocks, ch. 7

In this chapter some aspects of the distribution and processes controlling the abundance of 18O and 13C in hydrothermal systems are discussed. The term hydrothermal refers to hot, mineralized fluids which, in this specific case, deposited economic amounts of ore minerals in sedimentary rocks. Such ore minerals contain, only in exceptional cases, significant amounts of oxygen and carbon but both are normally very abundant in the associated gangue minerals: carbonates and silicates. Therefore, most stable isotope investigations which use 18O or 13C are based on the distribution of these isotopes in these gangue minerals and it is evident that the paragenetic relationships between gangue and ore must be fully understood if such data are to yield information about the formation of ore minerals and the origin of fluids and metals. A more detailed discussion concentrates on four genetically different deposits: the Providencia mines in Mexico; the Bluebell Mine in British Columbia (Canada), the Pine Point deposits in the Northwest Territories (Canada), and the Eldorado Mines in the Beaverlodge district in Saskatchewan (Canada)