الطباقية الحياتية للفورامنيفراالطافية لتكوين شيرانش (الكامبانيان المتاخر -الماسترختيان الاوسط) في بئر بطمة 15 شمال غرب العراق

Biostratigraphy of Planktonic Foraminifera Within Shiranish Formation(Late Campanian-Middle Maastrichtian)in Butmah Well No. 15 Northwest Iraq

Eighteen plankonic foraminiferal species belonging to five genera have been identified within the studied section of Shiranish Formation in Butmah well no.15; which is divided into four biozones. The first zone represents the Late Campanian age while the other three zones extend within the Early and Middle Maastrichtian age These zones are: -Gansserina gansseri Zone-Globotruncana aegyptiaca Zone- Globotruncanella havanensis Zone-Globotruncanita calcarata Zone The age of the studied section in Butmah well no.15 has been fixed as Late Campanian to Middle Maastrichtian while the upper part of the Middle Maastrichtian and the whole Upper Maastrichtian are missing. According to this fact the contact surface between Shiranish and Aaliji Formations is an unconformity surface.