Biozonation (Benthic Foraminifera) Of Mishrif Formation At Majnoon And Zubair Oil Fields, Southern Iraq

The Mishrif Formation represents a carbonate succession that deposited in major parts of the Arabian Plate during Cenomanian stage. formation is rich fossils including foraminifera, rudists, and algae. This study includes determination biozones biostratigraphic limits three boreholes sections (Cenomanian) from Majnoon Zubair oil fields southern Iraq within Mesopotamian Basin. A new scheme introduced based on benthic foraminifera occur complete Formation. Depending vertical distribution four studied have been established, they include: 1 - Miliolids Abundance Biozone characterized by first appearance miliolids to Nezzazata conica, include rudist, gastropoda, pelecypoda algae, 2 simplex – conica Concurrent (Middle Cenomanian) distinguished simplex, Praealveolina cretacea, Pseudorhapydionia laurinensis. Other associated concave, tenuis, Chrysalidina sp., Cuneolina pavonia, Multispirina iranica, Biconcava bentori, Qataria dukhani, Dicyclina schlumbergari, Tabrina beingstani, Cisalveolina Carinoconus iraqiensis. 3 Pseudorhapydionian laurinensis cretacea (Early Late identified last occurrence with Psudorhapydionian laurinensis, Praealveoilina both taxa. biozone also shows fallax, Tabarian bingstani, iraqiensis, Spiroloculina gradata, Pseudotexularella schlumbergari. 4 Pseudolituonella reicheli-Chrysalidina gradata (Latest marked reicheli gradate. diagnosed Rotalia Quinquelaculina Nummulculina heimi, Discorbis sp. Based stratigraphic ranges available sections, age estimated be Middle-latest Cenomanian.