Planktonic Foraminiferal Biostratigraphy of the Upper part of Balambo Formation (Lower-Upper Cretaceous) in Azmer Anticline, Northeastern Iraq
Abstract
The present work is a part of detailed study of biostratigraphy of Balambo Formation (Lower - Upper Cretaceous) from Azmer anticline - northeastern Iraq. Lithologically, the upper part of the studied section (Balambo Formation) consists of dark gray, reddish brown shale and marl intercalation with amonitic and marly limestone. Based on planktonic foraminifera, the studied section is divided into five main biozones and two subzones. It is correlated with collection of global regional and local previous biozones. These biozones led to conclude that the age of the upper part of Balambo Formation extends over the Latest Aptian to Middle-Late Cenomanian. Moreover, the identified biozones are from older (at bottom) to younger (at top): 5- Rotalipora cushmani Taxon range Zone. 4- Thalmanninella globotruncanoides Interval Zone. 3- Biticinella breggiensis Interval Zon. Ticinella praeticinensis Interval Subzone. Pseudothalmanninella subticinensis Interval Subzone. 2- Ticinella primula Interval Zone. 1- Paraticinella eubejaouensis Taxon range Zone. ) ( . - - . . . ) ( ) (: - 5- Rotalipora cushmani Taxon range Zone. 4- Thalmanninella globotruncanoides Interval Zone. 3- Biticinella breggiensis Interval Zone. . Ticinella praeticinensis Interval Subzone. Pseudothalmanninella subticinensis Interval Subzone. 2- Ticinella primula Interval Zone. 1-Paraticinella eubejaouensis Taxon range Zone.
