Dinoflagellate cysts from the Upper Triassic (Rhaetian) strata of the Tabas Block, East - Central Iran

Rhaetian strata from the Nayband Formation of the Tabas block, East- Central Iran, were studied palynologically. The materialexamined contained moderately diverse and well-preserved dinoflagellate cyst assemblages which lead to the identification ofRhaetogonyaulax rhaetica Zone. The assigned age of this dinozone (Rhaetian) is justified by plant fossils such as Equisetitesarenaceus, Scytophyllum persicum, Pterophyllum bavieri, Pterophyllum aequale and Nilssoniopteris musafolia recorded from thesestrata. The dinoflagellate cysts show close similarities with assemblages reported from Australia, Northwest Europe, Arctic Canadaand Northern Iran. Furthermore, the associated marine palynomorphs (dinoflagellate cysts), accompanied by spores grain indicate anearshore depositional environment for the Late Triassic (Rhaetian) deposits in Tabas Block of Iran.