Microfacies, Depositional Environments and Sequence Stratigraphy of the Lower and Middle Triassic deposits in Kelarize Section

Limestones of Elika Formation, were deposited in some part of the Alborz range during sea-level rise of early Triassic. The Elika Formation in Kelarize consists of two members. The lower members (lower Triassic) has been mostly deposited during storm and quiet periods, while the upper member (Middle Triassic) has been exclusively deposited during quiet periods. Thickness of the Elika Formation at the Kelarize section is up to192 m. The Elika Formation in the Study area, is unconformably overlain by the Shemshak Formation. Petrography and microfacies of the Elika Formation indicate that the calcareous microfacies are deposited in four depositional sub-environments including, open marine, bar, lagoons and tidal flat. Sedimentary environment of this formation in Kelarize section is very similar to the recent carbonate basins. These sediments are deposited in a homoclinal ramp. Based on field observations, thin sections study and sedimentary facies, 3 third-order sequences were recognized. Each sequence consists of a few shallowing upward para-sequence.