CALCAREOUS NANNOFOSSILS BIOSTRATIGRAPHY OF THE SHIRANISH FORMATION FROM AJEEL-10 WELL, NORTH IRAQ
Calcareous Nannofossils are studied from the Shiranish Formation in Ajeel well No. (10), 30 Km North East of Tikrit City, the study covers the depth interval (1350 – 1500) m, which is investigated to identify calcareous nannofossils species. Based on twenty-five identified calacareous nannofossils belonging to eleven genera, three biozones are identified which reflect outer shelf and basinal environments in the studied section. These are from older to younger: Uniplanarius trifidus Range Zone (CC22) (Part), Tranolithus phacelosus Interval Biozone (CC23) and Reinhardites levis Interval Biozone (CC24) (Part). These biozones are correlated with other calcareous nannofossils biozones from regional view which led to conclude that the age of the studied section is Late Campanian to Early Maastrichtian.