The Lower Jurassic Ab-Haji Formation consists of siliciclastic strata which are widespread and superbly exposed across the Tabas and Lut blocks of east-central Iran. The sequence stratigraphy analysis of the formation is crucial for palaeogeographic and palaeoenvironmental reconstructions during the Early Jurassic. Within this study, we measured and studied seven outcrop sections of the Ab-Haji Formation and based on facies change, major sequence stratigraphy surfaces and stacking patterns, the system tracts and depositional sequence were identified. Sequence stratigraphic analysis of the studied sections and its correlation showed four major regressive and transgressive stages during the deposition of the Ab-Haji Formation in east central Iran. The most complete depositional sequences (three complete third-order depositional sequences and one incomplete sequence) were deposited in some parts of basin with maximum subsidence rate, while, the sections located on uplifted parts of the basin, erosion and non-deposition prevailed or only one complete third-order depositional sequence were deposited. The pattern of depositional sequences confirm a tectonic model showing large tilted fault blocks in an extensional basin in eastcentral Iran during Early Jurassic.

کلمات کلیدی