Title: Marine palynology and environmental interpretation of the Lower Cretaceous (Barremian?–Aptian) rock units in the Koppeh-Dagh Basin, NE Iran
Abstract: The Sarcheshmeh and Sanganeh for ma tions are the Lower Cre ta ceous deep ma rine se quences of the Koppeh-Dagh sed imen tary ba sin, which re vealed a di verse as sem blage of dinoflagellates.The pa per dis cusses palynostratigraphy, palynofacies and palaeoenvironment of these rock units in a bore hole drilled in the east ern part of this ba sin.Ninety-five ditch-cut ting sam ples were pre pared and stud ied paly no logi cal ly, which re sulted in rec og ni tion of 76 spe cies of dinoflagellate cysts be long ing to 29 gen era.The re corded as sem blages are in ac cor dance with the Odontochitina operculata Zone suggest ing a Barremian?-Aptianage for the for ma tions.Palynological data ex tracted led to iden ti fi ca tion of five palynofacies types based on the cat e go ries of Tyson (1995).These in di cate a mar ginal, prox i mal and dis tal shelf en vi ron ment of de po sition.The ob tained data from cal cu lated palaeo eco logi cal fac tors re vealed a grad ual sea level rise dur ing the de po si tion of these rock units, re sult ing in re place ment of the oxic/dysoxic Sarcheshmeh For ma tion by the dysoxic/anoxic Sanganeh Forma tion.