Depth determination of oligosteginids limestone basedon planktonic foraminifera in kolah Qazi area.

Category Paleontology and Stratigraphy
Group GSI.IR
Location 20th symposium on geosciences
Holding Date 16 April 2008

     Kolah Qazi area is a part of Central Iran Zone. Study of planktonic foraminifera led to recognition of three morphotype groupes. First morphotype group is charachteristed by trochospiral or biserial tests with globular chambers and indicates shallow waters. Hedbergella & Heterohelix from planktonic foraminifera, and Stomisphaera sphaeric, Pitonella ovalis, Calcisphaerula innominata from oligosteginids are in this group. Second morphotype group is index of intermediate waters and consists of heavily ornamented globular, unkeeled chambers (Whiteinella archaeocretaceae), pustulose margins (Praeglobotruncana stephani) and single or double keels (Dicarinella primitiva, Marginotruncana renzi, Marginotruncana coronata) species. Third morphotype group is characterised by planoconvex trochospiral (Helvetoglobotruncana praehcl vetica), or high trochospiral (Praeglobotruncana gibba) tests and indicates deep waters. Study of morphotype group of planktonic foraminifera reveals an overall regression through the succession.