Sequence Stratigraphy of Sarcheshmeh Formation carbonates in Southern Aghdarband in east Kopet Dagh Basin
The Lower Aptian Sarcheshmeh Formation is exposed along the northwest- southeast trend in southern Aghdarband area in east KopetDaghBasin. It mainly consists of marl, limestone and shale It is overlain by the Sanganeh and underlain by the Tirgan Formations. Thicknesses of Sarcheshmeh Formation decreases gradually from NW toward SE. Eight stratigraphic section have been measured in southern Aghdarband to determine their facies and sequence stratigraphy. Field and petrographic studies are revealed that Sarcheshmeh Formation is composed of 23 microfacies that are deposited in 4 facies belts including open marine, bar, lagoon and tidal flat. Based on vertical variation of microfacies and relative interpreted sea level change, one 3rd order depositional sequence (DS1) recognized that the sediments were deposited during 2.5 m.y. that including of several small-scale shallowing upward cycles (Parasequences). The base and top of this sequence bounded by type 2. It is relatively similar to the global sea level changes curve with differences related to local and regional geologic events.