Sequence stratigraphy of the Hauterivian–Barremian time interval in land and offshore of the Bandar Abbas Area (SE Zagros, Iran)

Abstract

Gadvan and the upper part of the Fahliyan formations in the Zagros basin are part of the Khami Group and are correlatable with the Habshan, Lekhwair, and Kharaib formations of the Arabian Platform. Gadvan Formation has mainly a potential of hydrocarbon source rock and Fahliyan Formation has a potential of reservoir rock. In the study area, the upper Fahliyan Formation contains cliff-forming limestone and Gadvan Formation are mainly composed of high burrowed and bioturbated skeletal and argillious limestones. These sediments contain about 10 lithofacies that were deposited on a carbonate ramp system developed through the epeiric sea. Biostratigraphy of the study area and carbon isotope stratigraphy of outcropped interval create a good basis for sequence stratigraphic analysis. Upper and lower boundaries of the study interval show karstic evidences developed near Barremian–Aptian and Valanginian–Hauterivian boundaries, respectively. About three depositional sequences were identified in these intervals: Hauterivian–Barremian-age Sequence 1 and Barremian-age sequences 2 and 3 that are deepened toward studied wells. The Global Faraoni Oceanic anoxic event and Mid Barremian Event can play major roles in source rock potential enhancement of Gadvan and upper Fahliyan formations.