Sedimentary Evolution of Late Ordovician Sequence in El-Feel Field – An Example of Integrated Sedimentologic, Stratigraphic and 3D Seismic Data

New data concerning the Mamuniyat and Melaz Shugran Fms. in El-Feel Field. are presented. Integrating palynological analyses with sedimentological and 3D seismic data, the physical stratigraphic framework and the vertical sedimentary evolution of the Cambro-Ordovician sequence were defined. The regionally recognised paleohighs-lows model in Mamuniyat Fm. seems not to be supported at the field scale. What was previously defined as Hawaz Fm. in some wells is now ascribed to Mamuniyat Fm. and, as a consequence, it wouldn’t represent the infilling of the morphological lows among the Hawaz paleohighs. Mamuniyat Fm. might represent the infilling of a large scale physiographic element whose edges are not recognisable within the 3D seismic grid. The Melaz Shugran Fm. is quite organised in terms of vertical stacking pattern showing some differences with respect to the classic shaly sequence found in the Murzuk Basin. The regional map of the Melaz Shugran Fm. facies distribution would suggest the occurrence of an extensive fluvio-deltaic depositional system sourced from the South possibly originated by the melting of the ice front during the Ordovician glaciation.