الفهرس 
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Abstract
The Upper Cretaceous-Lower Paleogene successions exposed in the study area at Farafra Oasis in Western Desert, have been studied in terms of foraminiferal distribution to figure out the biostratigraphical distribution and sedimentary environment of these successions.
Two sections were measured, one at Naqb El-Farafra area, and the other to the south at the western scarp of Farafra Oasis which is El-Guss Abu Said plateau. The Eocene succession of El-Guss Abu Said consists of Esna Formation (shale) at the base, which is overlain by well-bedded alveoline marl (Nusf Formation) with occasional limestone ledges rich in Nummulites. Nusf Formation ends with varved-like thin beds of marl and limestone before it is truncated by a limestone unit of the Farafra Formation.
Nummulites has been investigated thoroughly to identify them and determine the age of upper part of the succession. Two species of Nummulites were identified; Nummulites solitarius De La Harpe 1883 and Nummulites fraasi De La Harpe 1883. These two species date this unit to Early Eocene time (Ypresian) .These two species assign this unit to Early Eocene time (Ypresian) that ranges from SBZ5 to SBZ6 of the standard Serra-Kiel et al. (1998) shallow benthic zonal scheme and Papazzoni et al. (2017) updated shallow benthic zonal scheme. El Nusf Formation ends with varved-like thin beds of marl and limestone before it is truncated by limestone unit of the Farafra Formation. Depending upon studying the vertical distribution of the planktonic foraminifera, El-Guss Abu Said succession can be divided into two international zones namely, Morozovella marginodentata (E3) and Morozovella formosa formosa (E4). M. marginodentata Zone is locally subdivided into three subzones namely in stratigraphic order, Morozovella subbotinae, Acarinina esnehensis and Parasubbotinae inaquispira.
Naqb El-Farafra succession consists of Khoman Formation, which extends in age to the Cretaceous- Lower Paleogene. Khoman Formation was studied sratigraphically with the aid of planktonic foraminifera where the K/Pg boumdary is recorded and eight planktonic zones were established. These zones are Globotruncana aegyptiaca Zone, Gansserina gansseri Zone, Racemiguembelina fructicosa Zone, Pseudoguembelina hariaensis/ Gansserina gansseri Zone, Pseudoguemblina Palpebra Zone, Parasubbotina pseudobulloides Zone Subbotina triloculinoides Zone and Igorina albeari Zone.
Benthic foraminifera have been used to determine the paleoecology of the study area, where the benthic foraminiferal assemblages are used to determine the paleoenvironments of the studied successions and Planktonic/Benthic ratio of all washed samples has been calculated. Three benthic foraminiferal associations have been detected at Naqb El-Farafra succession indicating deep outer shelf environment at its lower part and inner-middle shelf environments at the upper part of the succession.
Investigating the benthic foraminiferal associations of the Early Eocene succession of El-Guss Abu-Said revealed that the succession can be subdivided also into three benthic associations. These associations revealed that, Esna Formation at the lower part of the succession has been deposited in a deep outer shelf environment. At the upper part, the scarcity of small foraminifera and rich occurrence of Alveolines and Nummulites in the Nusf Formation point to a carbonate platform environment and this can be also extended to Farafra Formation. This also seems in harmony with the calculated P/B ratio. This shifting from deep outer shelf facies to the carbonate platform one could point to a tectonic uplift that occurred during Early Eocene time.
Concerning the investigation of the nature of sedimentation, microscopic thin sections representing the different rock types in Naqb El –Farafra succession have been carefully examined for demonstrating the diagenetic processes as glauconitization and dolomitization and finally detecting the nature of deposition in the study area.