Calcareous Nannofossil Biostratigraphy and Ostracoda Paleoecology of Hartha Formation from Balad (1) well, Central Iraq

Omar Ahmed  Al-Badrani; Faris Nejris  Hassan; Mahfoudh Abdulla  Al-Hadeedy

doi:10.24996/ijs.2021.62.11.17

Authors

Omar Ahmed Al-Badrani Department of Geology, College of Science, Mosul University, Iraq
Faris Nejris Hassan Department of Applied Earth Science, College of Science, Tikrit University, Iraq
Mahfoudh Abdulla Al-Hadeedy Department of Geology, College of Science, Mosul University, Iraq

DOI:

https://doi.org/10.24996/ijs.2021.62.11.17

Keywords:

Nanno-biostratigraphy, Ostracoda paleoecology, Cretaceous, Iraq

Abstract

Seventeen samples of Hartha Formation in Balad (1) well, central Iraq, are studied on the basis of stratigraphic ranges of the recorded calcareous nannofossils for twenty species belonging to twelve genera. The studied section reveals three biozones arranged from oldest to youngest as follows; (1) Calculites ovalis Interval Biozone (CC19), (2) Ceratolithoides aculeus Interval Biozone (CC20), (3) Quadrum sissinghii Interval Biozone (CC21). These Biozones are correlated with other calcareous nannofossils biozones from both local and regional sections, leading to conclude the age of the Middle Campanian.

Rerecorded eighteen ostracode species that belong to eleven genera are identified, all of which were previously recorded from Iraq and adjacent regions. The occurrence of these species leads to conclude a continental shelf environment, while they are typical of inner shelf-outer shelf depth.