الملخص

The Iraqi phosphorites distributed in western desert belong to Tethys phosphorites. They are found in Al-Rutba- H3, Al-Ga'ara, Akashat, and Al-Ethna and in the western wadi Aakash areas. The statistical factor analysis shows that the main five factors playing great roles in phosphate formation in the congenital shelf are the more active factors that control the mineralogical and geochemical distributions in phosphorites; they are (1) Phosphorus enrichment factor, which led to apatite (francolite) formation. (2) Depositional environment factor, which represents the deposition of phosphates in continental shelf of the southern part of Tethys Sea. (3) Mg withdrawing from sea water, the factor which controlled by clay mineral transportation like palygorskite and some dolomite that contributes to form apatite. (4) The slightly increased saline factor. (5) The cyclic alternative deposition factor, which represents the sequence deposition of phosphates, carbonates and cherts periodically.