Author/Authors :
Notghi Moghaddam، Marziyeh نويسنده Payame Noor University , , Hadavi، Fatemeh نويسنده Dept. of Geology, Faculty of Science, Ferdowsi University of Mashhad, Mashhad, IR Iran , , Anvar Moheghy، Mohammad نويسنده Ferdowsi University of Mashhad ,
Abstract :
This study presents the nannostratigraphy and nannofossil events in the lower boundary of Kalat Formation in the East and West of the
Kopeh- Dagh basin. The Kalat Formation comprises of coarse grained detritus limestone with subordinate sandstone intercalations. In the
current study, six sections have been chosen in the East and West of the basin which are as follow: Dobaradar section, Kalat section,
Chahchaheh section, Sheikh section, Qaleh Zoo section and Jozak section. In the Dobaradar section 22 species have been determined, in
the Kalat section 25 species, in the Chahchaheh section 32 species, in the Sheikh section 28 species, in the Qaleh Zoo section 20 species,
and in the Jozak section 18 species have been determined. The boistratigraphy based on calcareous nannofossils allows the identification
of nannofossil standard zones CC25- CC26 in the East, and CC21 and CC26 in the West of the Kopeh- Dagh Basin in all of the sections,
indicating that the investigated deposits are Late Maastrichtian – late Late Maastrichtian in age in all sections in the East, and early Late
Campanian – late Late Maastrichtian in all sections in the West of the Kopeh- Dagh Basin. The nannofossils response to the
Maastrichtian climate evolution is investigated in the lower boundary of Kalat Formation. Warm water indicators (Uniplanarius
sissinghii, Micula murus and Micula prinsii) suggest warm surface water conditions in the studied thickness. In the lower boundary of the
Kalat Formation, based on Lithraphidites spp. and Watznaueria barnesae, lower fertility conditions with low productivity at the end of the
Maastrichtian were suggested.
