PRODUCTIVE SERIES AS A GRAVITY-DRIVEN HIGH-RATE LACUSTRINE FORMATION, SOUTH CASPIAN BASIN
(INSIGHTS FROM FIELD-EXPOSURE OBSERVATIONS)

R. Kh. Khayrulin
Academy of Sciences of Azerbaijan Republic

Productive series (PS) is not only a major oil-producing formation in Azerbaijan, but also is distinguished because of high depositional rate and specific environmental features. Despite over a century of exploring history its origin still remains uncertain so far.

PS comprises a thick (over 5000m) succession of dominantly shale, silt and sand alternation with embodied subaqueous slumps, blocky inclusions, shale rip-ups, debris flows, turbidites and unconformity surfaces.

PS origin has been considered over the general paleotectonic and basin evolution background during the Neogene. Its depositional model is based on extensive field exposure and available core samples, as well as published data related to the global Neogene depositional features typified in general by high rates and interpreted to be generated through relevant gravity-driven flow mechanism.

The PS basin architecture was inherited from the ancestral paleo-Tethys. Euro-Asia and Arabic plates convergence along with pre-Pliocene relative sea level fall have resulted in isolated, self-consistent lacustrine type Caspian basin characterized by the absence of granite layer like Gulf of Mexico, Mediterranean, Black Sea and therefore can be called a "small ocean".