CAUCASUS MAYKOPIAN KEROGENOUS SHALE SEQUENCES: GENERATIVE POTENTIAL

The generative potential of kerogenous shale sequences in the Caucasus Maykopian series, the southern part of European Russia, is evaluated. The Khadum and Batalpashin sediments in the Eastern and Central Fore-Caucasus include three types of kerogen: I, II and III. The Khadum sediments are dominated by a more "noble" type II kerogen, mixed humic-sapropelic organic matter (OM). The Maykopian series may be attributed to the category of "rich" and "very rich" ("outstanding") oil source rocks. The maturity extent of the subject sediments within the region varies between the grades of protokatagenesis (maximum pyrolysis temperature ([T.sub.max]) = 390 [degrees]C) and [MC.sub.4] ([T.sub.max] = 471 [degrees]C). Based on the pyrolytic studies, the Khadum and Batalpashin sediments are distinct from other pelitic rocks in rather high generative potential values. The average value of the total generative potential ([S.sub.1] + [S.sub.2]) in the studied samples from the Khadum and Batalpashin Formations is 4.83 mg HC/g rock. The quantitative estimate of the hydrocarbon generative potential of the Khadum and Batalpashin sediments in this region was conducted for the first time. The total initial generative hydrocarbon potential of the sediments is 133.4 BT, being 92.7 BT for the Khadum Formation, and 40.7 BT for the Batalpashin Formation. Keywords: organic carbon, katagenesis, generation potential, source rock, Khadum Formation, Batalpashin Formation, shale strata.