Sequence Stratigraphy of the Sarvak Formation in Samand Well NO.1 (Ilam Area): Sequence Stratigraphic studies of the deep marine portion of the Neotethys passive margin
The Sarvak Formation (Albian-Turonian) composed mainly of carbonate rocks, is one of the main reservoir rocks in southwest Iran. Microscopic studies of well cuttings and gamma ray log analysis of this formation of Samand Well NO.1 (Ilam area) indicate that the Sarvak Formation was deposited in off platform (deep and shallow marine), barrier and back barrier lagoon facies belts related to a rimmed shelf. in the study area Sarvak Formation consists mainly of deep marine facies.
Sequence stratigraphy of the Sarvak Formation indicates the presence of four depositional sequences with type 2 sequence boundaries. Although in most places of Zagros region the Upper and Lower boundaries of the Sarvak Formation are disconformable (type 1 sequence boundary) in study area this boundaries are correlative conformities. Calciturbidites interbedded with plagic carbonates indicate deposition in a shelf type platform. High depositional rate during highstand resulted in off platform transportation of carbonate and deposition in a basinal area.
Middle Turonian regression and platform exposure resulted in the deposition of the plagic and residemented silicicalstics of the Sourgah Formation.