New Mexico Geological Society Annual Spring Meeting — Abstracts

Pyrolysis-gas chromatography provides a means of distinguishing fossil resin of different geological and botanical origin. The data described here result from stratigraphic and geochemical work on coal-bearing stratigraphic sequences in the San Juan Basin of New Mexico.

Fossil resins provide a relatively large sample of di- and sesquiterpene biomarks. The pyrolysis-gas chromatography of fossil resin associated with fossil plant material indicates botanical affinities. The same technique applied to secondary fossil resins, those associated with low-rank coals (less than coal seams. Then too, recent studies suggest that fossil resins may be to yield light napthenic oils at relatively low Ievels of thermal maturity. The technique is Iimited by differences in diagenetic history and the ambiguity inherent in interpretation of data from the physical and chemical analyses of complex mixtures. Identification of elements of chemical structure and their reIative abundance in fossil resin samples by infrared spectroscopy amplifies the information gained from pyrolysis-gas chromatography.