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 material examined contained moderately diverse and well-preserved dinoflagellate cyst assemblages which lead to the identification of Rhaetogonyaulax rhaetica Zone. The assigned age of this dinozone (Rhaetian) is justified by plant fossils such as Equisetites arenaceus، Scytophyllum persicum، Pterophyllum bavieri، Pterophyllum aequale and Nilssoniopteris musafolia recorded from these strata. The dinoflagellate cysts show close similarities with assemblages reported from Australia، Northwest Europe، Arctic Canada and Northern Iran. Furthermore، the associated marine palynomorphs (dinoflagellate cysts، accompanied by spores grain indicate a nearshore depositional environment for the Late Triassic (Rhaetian) deposits in Tabas Block of Iran.