Biostratigraphyand Paleoenvironments of Benthic Foraminifera From Lower Part of the Damlouk Member, Western Desert, Iraq

Age and paleoenvironment of part the Damlouk Member, Ratga Formation from a surface section in Iraqi Western Desert are investigated. Twenty-nine species Larger Benthic Foraminifera (LBF) belonging to 13 genera recognized studied section. The LBF assemblage is dominated by following groups, Nummulites, Alveolina, Rotalia, Lockhartia. Two corals with fragments bryozoan, red algae mollusca had also been identified. palaeontological investigation aimed at identification assemblages evaluate their abundance distribution respect sedimentary environment determine its age. Based on it subdivided into two biozones: Nummulites gizhensis -Nummulites moculatus Assemblage Zone Assilina spira- Lokharatia hunti Concurrent Range Zone. Both biozones suggest Middle - Late Lutetian Early Bartonian concentrated around shallow marine carbonate bank-controlled limestone unit associated ramp facies. basic environmentally significant were based vertical relative LBF. Nummulite bank characterized lensoidal robust different species. other group fore-bank which shows relatively higher diversity, including flat such as: Nummulite, Assilina, Lockhartia, Heterostigina Operculina. third back-bank not well presented section, limited distribution, considered lagoon This occurrence Alveolina imperforated forams. represent transition inner middle facies water depth exceeding 50m low energy conditions.