Implications of hydrocarbons in gold-bearing epithermal systems: Selected examples from the Canadian Cordillera

The generation of hydrocarbons through hydrothermal processes has been widely discussed and documented (e.g. Kawka and Simoneit, 1987; Didyk and Simoneit, 1989; Clifton et al., 1990, Kvenvolden and Simoneit, 1990; Peter et al., 1991). Hydrocarbon generation occurs in response to the maturation of organic matter caused by hydrothermal fluid convection generally related to magmatic or volcanic activity Unlike sedimentary basins, where oil generation usually occurs within a temperature range of 50–120°C (e.g. Hunt, 1979; Tissot and Welte, 1984) and cracking to natural gas takes place between 150 and 250°C (e.g., Kartsev et al.,1971; Vassoevich et al., 1974), hydrothermal systems can generate oil and petroleum-like products almost instantaneously (Simoneit and Lonsdale, 1982) from organic matter of a wide maturation range (e.g., Simoneit, 1988). As a result, immature biomarkers as well as compounds derived from highly mature organic matter can be found in hydrocarbons from hydrothermal systems.