An integrated sedimentological and stratigraphic study of the Ab-Haji Formation is crucial for palaeogeographic reconstructions of central Iran because it reflects the geodynamic history of the region during and in the aftermath of the main Cimmerian event (Triassic Jurassic boundary to Liassic). We measured and studied seven well-exposed outcrop sections in order to identify lithofacies and facies associations and to interpret the palaeoenvironment. Six facies associations are recognized: Fluvial plain, coastal plain, delta plain, delta front, prodelta, and shallow siliciclastic shelf. Reconstruction of the palaeogeography of eastcentral Iran shows a west-to-east and northwest-to-southeast continental-to-marine gradient. Based on thickness variations, lateral facies changes, palaeocurrent patterns, and changes in the nature of the basal contact of the Ab-Haji Formation on the Yazd, Tabas, and Lut blocks, the source of siliciclastic material was likely the fault-bounded Yazd Block in the west and the Shotori Swell at the eastern edge of the Tabas Block. The pattern of thickness variations, invoking large tilted fault blocks in an extensional basin.

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