A study of jeirud formation brachiopoda in theNortheast of Damaghan (Deh-Molla section)

Category Paleontology and Stratigraphy
Group GSI.IR
Location 21th symposium on geosciences
Holding Date 24 May 2008

      Deh-Molla section is located in the 54km northeast of Damghan. Lithology of Jeirud Formation in this section consists of sandstone, limestone, marly limestone and marl, and its thickness is about 76m. Jeirud Formation in this section has a lot of fossils of Brachiopoda, Trilobite, Crionida, Corals, Brayozoa and Conodonts, that the Brachiopoda are prodominent. Brachiopodas of Deh-Molla section was studied and 23 genera and 32 species were recognized that are as follows:
   Schellwinella sp.,Avonia sp., Mesoplica praelonga, Mesoplica aff. tas-adyrica, Buxtonia sp., Schizophoria impresa, Leptagonia sp., Aulacella interlineata, Gastrodetoechia iranica, Gastrodetoechia sp., Eoparaphorhynchus maclareni, Leptocaryorhynchus jamensis, Centrorhynchus charakensis, Araratella dichotomians dichotomians, Araratella dichotomians assimulata, Araratella sp., Paurogastroderhynchus nalivkini, Paurogastroderhynchus bikniensis, Megalopterorhynchus chanakchiensis, Cleiothyridina coloradensis, Cleiothyridina sp., Athyris sp., Athyris area, Athyris tau, Cyrtospirifer sergunkovae, Cyrtospirifer sp., Cyrtiopsis lapparenti, Rigauxia crassiplicatus, Rigauxia cyrtinaformis, Cyrtiopsis graciosa chakhaensis, Cyrtiorina iranica, Dichospirifer sp., Eobrachythyris sp.,
   Above mentioned Brachiopoda can be classified in the three assemblage biozones based on the their stratigraphical position and biostratigraphical value, and their ages ranged from Early Famennian- Late Famennian which equal to 9, 10, 11, and 12 biozones of Brice (1977) in Afghanistan.
   Keywords: Deh-Molla section, Jeirud Formation, Brachiopoda, Famennian, Biozone

tags: SEMNAN