Biostratigraphiy and paleoenvironment of the Karaj Formation at the Chehel-dokhtar Section, north of Shahrood

Category Paleontology and Stratigraphy
Group GSI.IR
Location The 24 Symposium of Geosciences
Holding Date 27 August 2007

The foraminifera of the shale and sandy limestone overling Fajan Formation at the Chehel-dokhtar Section, north of Shahrood, was studied. Eighty five samples collected and 29 species of  foraminifera recovered and treated systematically. The results indicate that the strata unconformably overling the Fajan Formation are representative of the Karaj Formation (lutetian) . Two biozones (Globigerapsis kugleri – Globigerina yeguaensis assemblage zone and Nummulites zone) were regionally established in Chehel-dokhtar Section. The presence of broken, megalospheric forms of bentonic foraminifera accompanied by coarse test and small size of planktonic foraminifera indicate a turbidity marine environment at the study section.