Gachsaran Fm

Column: Iran East

Synonym:

Alternating bands of Evaporite and Limestone. Member 7 (3068-2610 feet). It is alternating anhydrite and gray marl or marly limestone. Member 6 (4490-3553 feet). The basal 340 feet consists of alternating anhydrite, red marl, and, limestone. The middle part is alternating salt and anhydrite, and, the upper 200 feet is anhydrite with minor red to gray marl. Member 5 (3913-2850 feet). It is composed of mainly anhydrite alternating with limestone and red to gray marl. Member 4 (5175-2393 feet). Thick salt beds alternate with intervening gray marl, limestone, or, anhydrite. Member 3 (4974-4194 feet). It consists of thick anhydrite beds with subordinate salt in the lower half, and, alternating anhydrite, thin-bedded limestone, and, marl in the upper half. Member 2 (7713-7334 feet). It is made up of thick salt units with intervening anhydrite and thin limestone. Member 1 (7875-7745 feet). It consists of 130 feet of alternating thick-bedded anhydrite and thin-bedded limestone associated with bituminous shale.