An analysis of bitumens from the cave-in-rock fluorspar district, Southern Illinois

The southern Illinois fluorspar district has long been a rich source of fluorite, along with some economically important zinc and lead sulfides. The source of the fluorite and metallic sulfides has been described by various studies as either syngenetic, from lateral secretion of connate brines, or as hydrothermal deposits originating from deep-seated magma. Bituminous material occurs within the fluorite deposits as pockets, fluid inclusions and as coatings of fluorite and other mineral crystals. Study of the bitumens may provide clues as to their origin, and possibly the origin of mineralizing fluids in the area and the sequence of mineralizing episodes.No embarg