Sedimentary environment and provenance of sandstones from the Qadir member in the Nayband Formation, Tabas block, east-central Iran

Qadir Member of Nayband Formation, located in East Central Iran, has developed to a great extent. Investigation the lithofacies and sedimentary environment, resulted identification deltaic marine deposits. Based on field evidence facies features, consists two lithofacies, including carbonate siliciclastic facies. The were identified as having four sandstone Sr, Sh, Sp, St, three fine-grained FI, Fm, Fl (Sr) / Sr (FI) one coal Also, regarding field, laboratory studies, coastal plain, (including proximal delta front, distal prodelta) open environments for which is under impact tidal currents. chemical weathering index (71%) indicated semi-arid semi-humid conditions plotting geochemical data showed provenance re-cycling active continental margin because Chemical Index Alteration, rate was found be rather medium high. diagrams also probable source intermediate igneous rocks. this deposit could suggest Neotethys subduction Iran’s plate volcanic activity at end Triassic, coincided with early Cimmerian orogeny Alborz Iranian Microcontinent.