Investigation of the Silak Section Filyschoid Deposits based on Calcareous Nannofossils and Comparison with Shushud Section and Sarayan Section (East Lut Block)

In the present research biostratigraphy of the filyschoid deposits of the Silak section located at the eastern margin of Lut Block based on calcareous nannofossils was investigated. These deposits are about 420 m thick, and mainly contain shale, marl, calcareous sandstone and sandstone. From this section 118 samples were taken and prepared with smear slide method and then samples studied based on calcareous nannofossils. On the basis of the studied samples, 34 nannofossil species belong to 17 genera with medium preservation were identified and photographed. Based on the identified calcareous nannofossils, CC21 - CC26 biozones of Sissingh [24] in the section were determined. Determined biozones represent the late Campanian to the end of late Maastrichtian age for the investigated deposits in the Silak section. Study and comparison of the number of identified nannofossil species and determined biozones in the three sections: Silak, Sarayan and Shushud in the Lut Block show relatively same diversity of the species. However, species have better preservation in Sarayan section. In addition, difference in the biozones thickness in the studied sections may indicate a different sedimentation rate in the time interval of each biozones in different parts of the east of the Lut Block sedimentary basin.