Petro-Mineralogical Analysis of Sedimentary Phosphate of Marine Origin, Case of the Locality of El Kouif (Algerian-Tunisian Confines)

Abstract

The sedimentary phosphate of marine origin mark the Paleo-Eocene period in the region of Tebessa, as elsewhere in northern Africa. The study sector of El Kouif is considered as a part of the eastern Saharan Atlas. The lithological description of the studied Cups has allowed showing a bundle of phosphate take by carbonate formations sprinkle of flint. The grain size analysis of sandyphosphorites revealed phospharenite deposits which were generally heterometric and misclassified. Moreover, the mineralogical and magnetic analysis of some samples of phosphatic sands showed a predominance of light minerals. As well as the sorting and morphoscopic observation led the isolation of coprolites, of fossil teeth of fish and lithoclasts but mainly ovoid phosphatic pellets. The XRD analysis confirmed the presence of apatitic minerals (Hydroxyapatite, Fluroapatite, francolite and Dahlias), of carbonates (Calcite, Magnesium calcite, Ankerite, dolomite), the quartz, opal-CT and even sulphides and gypsum. The petrographic analysis of phosphate samples has permit to surround primordially, a phosphatic pellets rich in organic matter, devoid of nucleus and others nucleated. The phases of connections are clay, carbonate or silica. The notable amounts of allochems have an impact on textures of typewackstone, packstone, and sometimes grainstone for bio-pel-microspars.