RT Journal Article
T1 The uppermost deposits of the stratigraphic succession of the Farafra Depression (Western Desert, Egypt): Evolution to a Post-Eocene continental event
A1 Sanz Montero, M. Esther
A1 Wanas, H.
A1 Muñoz García, M.B.
A1 González Acebrón, Laura
A1 López, M.V.
AB This paper gives insight into continental sedimentary deposits that occur at the uppermost part of the stratigraphic succession present in the north-eastern sector of the Farafra Depression (Western Desert, Egypt). Using space imagery to complete the field work, the geology of the area has been mapped and the presence of a N–S oriented fault system is documented. The analysis of the morphotectonic features related to this fault system allows reconstructing the structural and sedimentological evolution of the area. The study indicates that the continental deposits were accumulated in alluvial systems that unconformably overlie shale and evaporitic rocks attributable to the Paleocene–Eocene Esna Formation. The deposits of the Esna Formation show soft-sediment  deformation features, which include slump associated to dish and pillar sedimentary structures and provide evidence of syndepositional tectonic activity during the sedimentation of this unit. The outcrops are preserved in two areas on separated faultbounded blocks. Proximal alluvial fan facies crop out in a dowthrown block close to the depression boundary. The proximal facies are made up mostly by polymictic conglomerates which occasionally contain boulders. The conglomerate clasts are mainly quartz, carbonate, anhydrite satin spar vein, mudrock, ironstone and nummulite fossils. The mid-fan facies consist of trough cross-bedded, rippled and  rosslaminated quartzarenites with reworked glauconite grains and carbonate rock fragments, interpreted as deposited by distributary streams. The distal alluvial fan deposits consist of sandy marls that evolve toward the top of the sections into root-bioturbated lacustrine limestone beds that are locally silicified. The limestones are biomicrites containing characea, ostracods and gastropods with fenestral porosity. A number of features, including clast provenance (mainly from marine Paleocene and Eocene rocks), the observed fractural pattern (N–S direction related to the opening of the Red Sea), and the sedimentary relationships, suggests that the continental deposits were accumulated during the Oligocene–Miocene interval.
PB Elsevier Science
SN 1464-343X
YR 2013
FD 2013
LK https://hdl.handle.net/20.500.14352/42955
UL https://hdl.handle.net/20.500.14352/42955
LA eng
NO Agencia Española de Cooperación al Desarrollo (AECID)
NO Universidad Complutense de Madrid
DS Docta Complutense
RD 29 abr 2024