TITLE:
Investigation of Main Planktonic Foraminiferal Bio-Events in Surgah Formation at Pol-e-Dokhtar Area, South Western of Iran
AUTHORS:
M. Vahidinia, M. Haddadi, M. Shafiee Ardestani
KEYWORDS:
Zagros Sedimentary Basin, Surgah Formation, Male-Kuh Section, Biostratigraphy, Planktonic Foraminifera
JOURNAL NAME:
Open Journal of Geology,
Vol.6 No.8,
August
18,
2016
ABSTRACT: Surgah Formation at Male-kuh well section with 82 meters thickness has
been studied at Pol-e-Dokhtar area. Surgah Formation at mentioned section was
composed of limestone and shaly limestone. The lower and upper contacts of
studied formation with Sarvak and Ilam formations are conformed. Based
planktonic foraminifera study 37 species belonging to 10 genera in frame of two
planktonic foraminiferal biozones were identified respectively as below: 1) Dicarinella concavata Interval Zone; 2) Dicarinella
asymetrica Total Range Zone. Finally, based on recent investigation have
been detected middle Turonian-Late Santonian age for studied section. According to (Robaszynski and Caron 1979), the first occurrence of Dicarinella
primitiva has been shown base of the Coniacian stage. The first occurrence
of Di. primitiva was placed under the Turonian-Coniacian boundary.
Robaszynski and Caron 1995 recorded the first occurrence of Dicarinella
primitiva and Dicarinella concavata were simultaneous and assigned
to late Turonian which correlated with ammonite’s species Subprionocyclus
neptuni. In the correlation between ammonite and Dicarinella primitiva at Tethyan realm first occurrence of Di. primitiva was close to the
Middle-Late Turonian sub stage. The base of Coniacian stage was identified based on the FODs of Archaeoglobigerina
cretacea and Dicarinella concavata from planktonic foraminifera with
FOD of Cremnoceramus walterdorfensis walterdorfensis from inoceramid
group, while the base of Santonian stage recorded using LOD of Dicarinella
primitiva, Whiteinellids group with FODs of Dicarinella asymetrica and Inoceramus aff. vistulensis (inoceramid species).