Study of Abtalkh formation based on ostracodea to determine paleoecology and paleoenvironment in Bafaraji section

In the North & E. North of Iran Kopeh Dagh basin has formed and begins from khazar sea, passes through Turkmenistan and Iran, then inter Afghanistan. Abtalkh formation is one of the sedimentary units of this basin that has been studied based on other fossils several times such as foraminifera, palinomorphs and nanoplanctons. The study area is located in 135 Kilometers of Mashhad-Kalat road, with geographical features North latitude 59° 46' 54" and Earst longitude 36° 55' 42", and its lithology is mostly of blue-gray chalky shale with layers of marn. Its down boundary with Abderaz formation and upper boundary with Neyzar formation is conformable and its thickness is 980 M. For studying of formation according to Ostracoda, 46 samples have been taken. For separating Ostracoda of surrounded sediment, samples were washed and then were photographed by electronically microscope. We organized 57 spices for 26 genus from Ostracoda. According to, age of Abtalkh formation is santonian-masterishtian.