Platform-Interior Evaporite Depositional Environments

During transgression, the shelf interior can be barred from the open sea, resulting in shallow, subtidal evaporitic conditions. Swallow-tail gypsum is commonly deposited in shallow water. It is preserved in the ancient record as palmate anhydrite (Loucks and Longman, 1982; Schreiber et al., 1982)

Examples of Miocene Subtidal Palmate Gypsum

Miocene evaporite from the Mediterranean region showing bedded vertical palmate gypsum structure. Photograph courtesy of B. C. Schreiber. Click in red box to see detail.

Ancient Lower Cretaceous Example of a Platform-Interior Setting of Palmate Gypsum Deposition

Depositional model of the formation of the Lower Cretaceous Ferry Lake platform-interior evaporites in East Texas. Grainstone shoals barred the platform-interior setting, creating restricted conditions behind the shoals. From Loucks and Longman (1982). Click on the red boxes to see rock samples.

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