John E. Zumberge, 1984. "Source Rocks of the La Luna Formation (Upper Cretaceous) in the Middle Magdalena Valley, Colombia", Petroleum Geochemistry and Source Rock Potential of Carbonate Rocks, James G. Palacas
Download citation file:
Marlstone outcrops (~40–50% total carbonate content) of the Upper Cretaceous La Luna Formation in the Middle Magdalena Valley, Colombia, average 4.3 wt% total organic carbon and 2,500 ppm extractable hydrocarbons. Microscopic and elemental analyses of La Luna kerogen suggest that the organic matter in these La Luna Samples is of marine origin and at a maturity level within the oil-generation zone. Geochemical fossil distributions attest to a marine-planktonic and microorganism source, owing to abundant C27 steranes relative to C29 steranes, low quantities of C19 and C20 tricyclic diterpanes relative to extended (up to C30) tricyclic terpanes, and the presence of ubiquitous hopane triterpanes derived from bacteria.