Writers : Khazaei, Ahmad Reza; supervisor: A. Aryaei; advisor: A. Ashouri
Refference : M.Sc. Thesis; Ferdowsi university:Mashhad
Publishing Year : 1375

Abstract :

In accordance with the stratratigraphic value of the Rudists, specially in up Cretaceous and their role in reef buildings, a number of studies were made on the Maastrichtian Rudists in the east of Kopet Dagh basin-NE Iran. In these investigations. the Rudistbect of the 5th member of Kalat formation in its type section in Tang-e-Neizar in Mashhad - Sarakhs road and a section 7 Kilonieters west of it, including two fossilferous horizons were studied and 8 sampled. On the whole. after studing the gathered samples, 11 genus and species of Rudists with a few samples of Gastropods. Bivalves and corals were determined ،and due to them, the up. Maasrrichtian age is recommended for these beds. On the basis of paleological studies these Rudists are of the elevator morphological group which show a still envirannient. high sedIimentary rate. shallow depth. high? temperature and salinity. Their association is found in the form of barrier and patch reefs and Tickets. In the Maastrichtian, the east Kapet Dagh area belonged to Tadjikistan Afghanistan- N Iran basin and In located in the Tethys ocean ( Supertethys Zone )and was near tropic. The microfacies of these beds include 5 faciaes wich totally indicate a harrier environment for Rudist beds, lagoonal environment for fine- grain sediments and forereef environment fo?grainstone sediments and have been deposited in a regrassive megacycle.

Subject List : Rudist