Nature et Origine des Cuirasses ferrugineuses de la région de Khat Oummat Elbid, Inchiri, Mauritanie.

This study was carried out in the Khatt Oummat Elbid (KOB) region which exposes ferruginous ducrists, We present new mineralogical, geochemical and structural data on the different KOB sequences allowing to classify the KOB ferriferous ducrists, our study shows the distribution of hematite in each level of the KOB ducrists, the state of the goethite, the presence or not of kaolinite. The chemical analysis of the main elements and the mineralogical analysis by X-ray diffraction make it possible to highlight certain specific characteristics of these ferruginous durcrists and to rule out other types of ferricretes known in the sub-region. It would also be necessary to combine the modified structural studies and the laboratory analyses in order to be able to propose, without ambiguity, a model of genesis of the KOB dusricrists. our results suggest an original mechanical and chemical allochthony which is not necessarily specific to ferruginous ducrists.