Devonian and Carboniferous Carbonate Platform Facies in the Bolshoi Karatau, Southern Kazakhstan

Abstract

The Bolshoi Karatau carbonates of southern Kazakstan record development of a 4,500 m. Thick platform which evolved close to the North Caspian Basin of western Kazakstan during the Late Devonian and Carboniferous (Cook et al, 1994). Carbonate facies in the Bolshoi Karatau mountains of southern Kazakstan provide outcrop analogs for coeval reservoirs in supergiant oil and gas fields in the North Caspian Basin (Fig. 1). The carbonate platforms in the Bolshoi Karatau and the North Caspian Basin are similar in several important ways. First, both the Bolshoi Karatau and the Tengiz oil field carbonate platforms were initiated in the Upper Devonian and ended in the Bashkirian, a span of about 50-55 my (Fig. 3; Lisovsky et al., 1992). Second, the stratigraphic thickness of the Bolshoi Karatau and the Tengiz oil field is similar (Fig. 2). Third, the proven oil reserves in Tengiz occur in the Visean through Bashkirian and these strata are well exposed in the Bolshoi Karatau (Figs. 2,3).