Depositional environment and sequence stratigraphy of the Fahliyan Formation: surface sections of Bidkhon and Khartang and subsurface sections of Nar-2 and west Aghar

Document Type: Original Article

Authors

1 Department of Geology, Faculty of Basic Sciences, Sciences & Research Branch, Islamic Azad University, Tehran, Iran

2 Exploration Directorate of National Iranian Oil Company, Tehran, Iran

3 Department of Geology, Faculty of Basic Sciences,Tarbiat Modarres University, Tehran, Iran

Abstract

The Fahliyan Formation of the upper Khami Group(Lower Cretaceous) is composed of carbonate rocks. In order to study facies, depositional environment and sequence stratigraphy of the Fahliyan Formation in the southwest of Fars Basin, surface sections (Bidkhon in Assaluyeh and Khartang anticlines) and subsurface sections (Nar-2 and West Aghar) have been studied. Field observations and petrographic studies indicate that the Fahliyan Formation deposited in four facies belts: tidal flat (A), lagoon (B), barrier(C) and open marine (D). Study of facies, their vertical and lateral changes and comparison with modern and ancient environments indicate that the Fahliyan Formation deposited in a Shelf carbonate platform with shallow environments. Sequence stratigraphy of the Fahliyan Formation in the area indicates on the existence of two depositional sequences (3rd-order cycles). In the studied sections, the lower and upper boundary of the first sequences and the top boundary of the second sequence are type 1 unconformity (SB1).

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