Evidence for Isolated Platform Development in the Cenomanian on the Passive Margin of Neotethys, Southwest Iran

Abstract

In the Cenomanian, the southern passive margin of the Neotethys Ocean was dominated by a giant carbonate factory. This succession is known as Sarvak Formation, a significant reservoir in Iran. This study focuses on a detailed analysis of facies variations and paleoenvironmental reconstruction, including the interpretation of the platform types, during this time interval. Based on field observations and petrographical studies, 12 facies have been recognized and ascribed to six facies belts on a carbonate ramp. Sub-environments include the outer ramp and basin (distal open marine), talus and channel (mid-ramp) and lagoon and shoal (inner-ramp). The frequency of the facies and isochore maps indicate the paleoenvironmental conditions and their spatial variations in the study area. Based on all data and analyses, the suggested conceptual model for the Sarvak Formation in the Lurestan Zone is an isolated platform surrounded by two ramps. The upwind and downwind parts of these ramps were located in the central and northern sub-zones of the Lurestan Zone. This model can be used as a template for isolated platforms worldwide.