Base and precious-metal mineralization of the Laney Shale and Bridger Formation, northern Green River Basin, Wyoming.

摘要

In the north central part of the Green River Basin, near Farson, Wyoming, a surface gold anomaly was reported by the National Uranium Resource Evaluation (NURE) program in 1980. Geochemical sampling confirmed the presence of a gold anomaly and established that a cobalt, nickel, and possibly a silver anomaly exists in the same area. The pristine nature of the gold particles precludes stream transport as the genetic mechanism for the gold concentration, nor are cobalt, nickel and silver concentrated by that process. Black trona brines (BTB), found in oil shale in the subsurface of this area, contain a similar suite of metals, are geopressured and are extremely organic-rich. A revised structural model of the area and a low temperature geochemical model are proposed which describes a genetic pathway that links the black trona brines with the metal anomalies.