ORGANIC GEOCHEMISTRY OF PASO DIABLO COALS (MARCELINA FM., PALEOCENE), VENEZUELA

Abstract

Six representative samples from different coal seams within the sequence of the Marcelina Formation (Paleocene) were subject to an organic geochemical study. The aim of the study is the establishment of the physicochemical environment conditions, the maturity level reached by the organic matter, and the variations within the log. Obtained results allowed classifying coals as high-bituminous type A, according with ASTM rules (1990), with low sulfur, moisture and ash, and very high in volatile matter content. Studied coals were derived from terrestrial organic matter, with negligible marine influence, settled in a continental environment, with minor facies changes, under strong dysoxic conditions (high Eh) and low salinity. Maturity of coals is associated with the beginning of oil window, in the first path of catagenesis of organic matter.