Sedimentary Environment and Provenance of Ab-Haji Sandstones in Cheshmeh Bakhshi and Sartakht-e-Shotoran Sections, Kalmard Block,Central Iran

Determination of sedimentary environment, provenance and tectonic setting of Ab-Haji Formation sandstones (Lower Jurassic) have been carried out in Cheshmeh Bakhshi and Sartakht-e-Shotoran sections which are located in Kalmard Block. Facies analysis of sedimentary facies in mentioned sections implies three clastic faceis associations including delta plain, delta front and prodelta and two carbonate facies, relevant to bar. The obtained results from modal analysis and geochemical data point to cratonic tectonic setting and presence of qurtzose rocks in the source area in the course of recycling processes. Moereover, using the tectonic discrimination diagrams suggest that Ab-Haji sandstones have been deposited in a passive continental margin. The calculated chemical index of alteration (CIA) nd the plagioclase index of alteration (PIA), based on major element oxides, denote moderate to intense weathering in the hinterland. This consequence is conformed with the modal analysis and petrographic evidence referring to humid and semi-humid climate.