الفهرس 
StratigraphyOnly 14 pages are availabe for public view
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Abstract
The present study contributes to the sedimentology and biosuatigraphy of the pre-Ce1101nania11-early Middle Eocene sequence in the Thamad area, east central sinai. A total 290 samples were collected from 12 exposure at 8 localities in the Thamad (Thenled) area. In this area, the Lower Cretaceous sandstone of the Malha Fonnation is overlain by the Upper Cretaceous-Paleogene sequence which is divided into seven formations that arranged from base to top as follow: 1) Galala Formation 2) Wata Formation 3) Thamad Formation 4) Rajim Formation 5) Sudr Formation (Markha Member) (Abu Zenilna Member) 6) Esna Fomation 7) Egma Formation Cenomanian Turonian Coniacian-Santonian Late Santonian/ Campanian? Late Campanian Late Maastrichtian Late Maastrichtian-Early Eocene Early Eocenelearly Middle Eocene The Lower Cretaceous Malha Fonnation is located at Gebel Khashm El Tarif (east El Thamad Village). It consists of varicoloured fluviatile sandstone that intercalated with thin kaolinite lenses. The Malha Fo~mationh as no fossil records and is overlain by the Galala Formation without visible unconformity. The Galala Formation is divided into three members: the Lower Clastic-Carbonate, the Middle Carbonate and the Upper Shale Members. The lower member is composed mainly of glauconitic dolostone and dolomitic sandstone that represents the first transgression of the Cenomanian sea. This member may have deposited in shallow intertidal-subtidal environments with high terrigenous input. The Middle Carbonate Member represents increased cycle of deposition. Two zones of megafossils are recognized in this member: the Rhyrlchostreorl s~rbor~bic~rlutr(rhmer ein suggested as Holecrypus larteti) Zone and Stromlms ir~certusZ one. The Upper Shale Member consists of nodulas limestone and masly limestone that capped by thick bed of yellowish shale. The macrofauna collected from this member suggest deposition in more agitated shallower water than the Middle Carbonate Member. Thirty eight sepecies of macrofuna are identified from the Galala Fornlation in this area and all belong to the Cenomanian age. The Galala Formation is overlain conformably by the Wata Formation which is divided into two members; the lower Shale Member and an Upper Carbonate Member. The lower member is made up of shales with interbedded gypsum beds whereas the upper member consists of ~nassivew, ell bedded limestone. The basal part of the Wata Formation consists of fosiliferous mas1 with large sized ammonites. Fossil records from the formation are rare but all of Turonian age. At Girf El Thamad, the Wata Formation is overlain by the Thamad Foimation which consists of well-bedded white highly lithified chalk rich in TI-igotmca spp. and Petalobr-issus wultlzeri. Southwest El Thatnad Village, this formation consists of fossiliferous mas1 and marly limestone with Plicatula fei-ryi and Oscillopha diclzotomu and caped by snow white chalk. The recorded macrofauna and nannoplankton taxa indicate that this formation is of Coniacian to Late Santonian age. The sediments were deposited in shallow to relatively deep water (pelagic) and stagnant to agitated environments. The Tlmnad Formation is conformably overlain by the Rajim Folmation which consists of marl, shales and calcareous shales that interbedded by hard limestone beds. The recorded fossils in this fonnation belong to Late Santonian/Easly Campanian?. It is unconformably overlain by the Upper Campanian Sudr Forlnation which consists of two members, Markha and overlying Abu Zenima. The contact between the two formations consists of chalk pebbles and phosphatic grains mixed with glauconite grains. The Markha Member consists of massive, chalk flooded in its basal part by large size Pyctlodotlte (Phygt-ma) vesicu1ar.e and embraces cliert bands in its upper part. The Abu Zenima Member is composed of marly chalk of Late Maastrichtian age. The sediments of the Sudr Formation may have deposited in a relatively deep to shallow shelf environment. The Sudr Formation is separated from the overlying Esna Formation by a thin conglon~eraticc halk bed but no palaeontologic break is noted between them. The latter consists of calcareous and argillaceous marl intercalated by carbonate ledges. The recorded nannofossil zones from tlie Esan Foniiation indicate Late Maastrichtian/Exly Eocene age. This formation may be deposited in a wide shallow shelf but away from the Iiinterland. The overlying Egma Formation is composed of massive to poorly bedded chalky limestone with several cliert bands. It has no megafossils but rich in calcareous nannoplankton oozes. The recorded nannofossil zones indicate Early Eocene to early Middle Eocene (Lutetian). The sediments of this formation are though to be of pelagic origin.