Sedimentological Analysis of the Facies from the Maastrichtian to Eocene Ages of the Ader Doutchi Sub-basin and Chronological Timing of the Different Fracturing Episodes

The present study covered the Ader Doutchi sub-basin, corresponding to the south-eastern part of the Iullemmeden basin. The sediment fill of the Ader Doutchi sub-basin is made up of deposits from the Maastrichtian to Eocene ages. The objective of this study is to: (i) analyze the vertical sequence of facies, (ii) identify the main fractures, (iii) chronologically map the main fractures from field observations and (iv) Determine the time sequence of major fracking events. The methodology implemented is based on field and laboratory work. The field work consisted of the survey of lithostratigraphic sections, with sampling and structural measurements. The laboratory work is all about processing structural data using the Win-Tensor 5-8-9 program. The sedimentological analysis of Maastrichtian to Ypresian deposits (lower eocene) reveals two main facies: one clay and the other marno-limestone. The analysis of fractures in the studied formations highlights three episodes of fracturing, D1, D2 and D3, associated with the Maastrichtian, Paleogene and Ypresian age deposits.