A Study of Biostratigraphy of Sinjar Formation in selected sections from northern Iraq


Late Paleocene –Early Eocene algae and benthic foraminifera were identified from the Sinjar Formation that crop out in three selected section from northern Iraq. The selected sections: (Derbandikhan ,Qara dagh, Wara Mali has been measured in the field and closely sampled to undertake details. A number of (131) samples were collected illustrating all the lithological changes along the sections, The limestone in the studied section is rich in algae and large benthic foraminifera, The investigation of the thin sections allowed us to identify the (47 ) species of foraminifera and (34) species of algae , Five biozones were distinguished for algae which are :a- Amphiroa iraquensis range zone ,b- Trinocladus perplexus range zone ,c- Lithothamnium – Pagodaporella wetzeli –Lithoporella melobesides Assemblage zone ,d- Cymopolia kurdistanensis- parkerella Sp.- Dissocladella deserta - Jania Sp. Assemblage zone, e- Clypeina merienda –Distichoplax biserialis -Mesophyllum Sp,.-Archaeolithothamnium cf dollonii Assemblage zone. Five biozones were distinguished for large benthic foraminifera which are :- a-Cuvillierina sireli – Cuvillierina vallensis - Cibicides nammalensis – Rotalia trochidiformis Assemblage zone ,b-Miscellane miscella –Discocylina varians Assemblage zone , c-Idalina sinjarica –Nummulites globulus –Spherogypsina globula –Somalina Sp.- Alveolina globosa Assemblage zone, d-Orbitolites Sp. - Assilina Sp.- Ovulites Sp.- Cribogoesella Sp, Assemblage zone, e-Opertorbitolites transitorius range zone. The age of this formation is Late Paleocene-Early Eocene in the studied section.