PRELIMINARY GEOCHEMICAL RESULTS AND CHARACTERIZATION OF THE MAIKOP SERIES, SHAMAKHA-GOBUSTAN OIL PROVINCE, EASTERN AZERBAIJAN

The Oligocene-Miocene Maikop Series is a world class source rock interval that is the source for much of the oil and gas found in the South Caspian Basin. Unfortunately, it has historically been a poorly understood stratigraphic interval due to the homogenous nature of the fine-grained, clay-dominated strata. Outcrop exposure in Eastern Azerbaijan allows direct observation and detailed sampling of this interval, leading to the identification of a more detailed stratigraphic scheme and a better understanding of the paleoconditions present in the eastern Paratethys Sea at the time of deposition. A variety of geochemical analyses such as pyrolysis, stable isotope and trace metal analysis, and bulk composition shows significant variation in depositional conditions during the Oligo-Miocene within the Southern Caspian Basin. The first suite of samples from the Shamakha-Gobustan oil province is made up of mostly Oligocene-aged strata according to biostratigraphic analysis, and certain trends have been identified that show appreciable differentiation between Rupelian- and Chattian-aged strata. On average, the Rupelian-aged strata show higher TOC values, more negative d15N values, more positive d13C values, and higher radioactivity relative to Chattian strata. The trace metals Mo and V (normalized to Al) show a positive correlation with TOC values, with maximum values near both the Rupelian-Chattian boundary and the Oligocene-Miocene transition. While these large trends are seen, it is obvious that there is a fair amount of source rock variation on a smaller scale, both vertically and laterally, with TOC values ranging from 0.25 to 5.62, and large variations in other geochemical parameters. A possible stratigraphic division between the Rupelian and Chattian sections of the Maikop Series is suggested by the data, and this idea will be reinforced or refuted by ongoing research in the area. Also, future work will focus on sampling more completely the Miocene section of the Maikop Series in an attempt to more fully characterize this important source rock interval.