nannostratigraphy and palaeoecology of tirgan and sarcheshmeh formations in taherabad and mozduran sections (east of kopeh-dagh)

in this study, calcareous nannofossils at the boundary between tirgan and sarcheshmeh formations at taherabad and mozduran sections have been studied. these sections are located in the eastern kopet-dagh basin. 22 nannoplankton species of 14 genera in taherabad section and 20 species of 14 genera in mozduran section were identified. according to the first occurrence of index species and fossil assemblages of calcareous nannofossil biozone (cc7) of sissingh (1977), the age of early aptian for this boundary in two sections have been recognized. based on identified calcareous nannofossil and palaeoecological data, boundary of tirgan-sarcheshmeh formations were deposited in relatively shallow marine environment and low-middle latitude.