Facies Architectuer and Stratigraphic Evolution of Campanian Succession in Balad, East Baghdad and Kifl Oil Fields

The sediments of the Hartha Formation were deposited during Upper Campanian- Maastrichtian cycle. Due to importance this sequence in terms stratification and economics oil industry, it has been focused on study. present study includes three fields central Iraq within Mesopotaminan Zone, East Baghdad, Balad Kifl fields. This was accomplished by describing 190 thin sections interpreting response available well logging data. Seven major microfacies diagnosed succession at studied fields, they are; Orbitoidal wackestone - packstone, miliolids wackestone, Rotaliidae Siderolites with echinodermata Peloidal echinoderm packstone grainestone, Pellets Planktonic foraminifera wackstone Evaporitic mudstone microfacies. These lagoon, restricted, shallow open marine, shoal, mid ramp outer ramp. represents one cycle third order cycles fourth (A1, A2 A3). are asymmetrical starts A where marine facies Lower TST underly HST, which bounded below a TS coinside unconformable surface (SB1) underlying Sadi Formation. highstand systems tract A1 is reflected Formation, represent thick then appear HST transgressive (TS) rampfacies A3. second disappeared Oil Field appeared evaporitic lagoon facies.