الفهرس 
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Abstract
The present thesis is concerned with the studying of the stratigraphy, br petrography, diagenesis and sedimentology of the stratigraphic succession br exposed at Mitla Pass and its environs at west Central Sinai. br Lithostratigraphically, the exposed stratigraphic succession could be br subdivided into; Masajid Formation of Oxfordian age at the base that is br followed upward by Risan Aneiza (?Aptian- Albian), Galala Formation br (Cenomanian), Abu Qada Formation (Late Cenomanian- Early Turonian), br Buttum Formation (early Middle Turonian), Wata Formation (late Middle- Late br Turonian), Themed Formation (Coniacian- Santonian), Sudr Chalk (Late br Campanian- Middle Maastrichtian), Mitla Formation (Late Maastrichtianearliest br Early Eocene), Thebes Formation (Early Yepresian) and Minia br Formation (Late Yepresian). br Biostratigraphically, this sequence is relatively rich in macrofossil br assemblages especially bivalves, gastropods, ammonites and echinoids. Based br on the FAD and LAD of the index species of the prementioned macrofossil br groups, an integrated biostratigraphic framework has been constructed for the br Upper Cretaceous succession of the area studied -#119;-#104;-#101;-#114;-#101; five ammonite zones br were recognized -#102;-#114;-#111;-#109; the Cenomanian- Turonian succession. Based on some br selected macroinvertebrates other than ammonites, twelve biozones were br proposed. The integration among the proposed biozones as well as local and br inter-regional correlation of the biozones has been discussed. br The petrographic study of limestone, dolostone and sandstone rocks br revealed, eighteen limestone, four dolostone and four sandstone microfacies br were recorded, besides shale, sandy shale, clay and marl facies. The molluscan br shell fragments, foraminiferal tests (planktonic, benthonic, and larger br foraminifers), echinoids, corals and coralline sponges are the main skeletal br II br components of the different lithofacies, -#119;-#104;-#101;-#114;-#101;as, micrite and sparite as well as br dolomite rhombs constitute the main orthochems. br Cementation, micritization, recrystallization, dolomitization and br silicification are the diagenetic processes that affected on the different studied br carbonate rocks. Three texturally different forms of cement were recognized; br drusy calcite, granular and blocky cement. The aggrading neomorphism br (recrystallization) of lime mud as well as the calcitization of aragonitic and br high magnesium calcitic shell fragments were recorded. Micritization process br is more common due to the action of borer organisms especially on the br echinoid plates and foraminiferal tests. Also, three main types of dolomite br rhombs were recognized; ferroan zoned and unzoned type, clear (limpid) type br and sandy dolostone type. The origin of the different types of dolomite rhombs br was discussed either by the effect of contamination of meteoric water with br marine water or clay derived mechanism or hypersaline mechanism. The br silicification process occurred in different forms of bedded chert, lenticular br chert, silicified skeletal particles, detrital mega quartz, chalcedony quartz, br spherulitic quartz and micron quartz. The origin of chert has been discussed. br Also, silica cementation, calcite cementation, dolomite replacement and br hematite cementation and pigmentation are the main digenetic processes that br affected on sandstone lithofacies. br The stratigraphic and petrographic studies carried out on the br stratigraphic succession -#102;-#114;-#111;-#109; Late Jurassic to Early Eocene show gradational br facies changes -#102;-#114;-#111;-#109; shallow to relatively deep marine environments along the br southwest-northeast direction of the area. The recognized facies and their br related paleoenvironments document lateral and common vertical transition br -#102;-#114;-#111;-#109; inner, middle to outer ramp setting. These facies could be subdivided into br eight associations; peritidal flat/beach clastics, peritidal flat carbonates, br lagoonal clastics, lagoonal carbonates, high energy shoal of ooids and patch br III br reefs (oolitic shoal), intertidal- subtidal open marine, storm influenced subtidal br open marine (mid- ramp) and hemipelagic (outer ramp) facies. br Generally, the area under investigation was controlled by a long term br transgressive phase and several higher -#111;-#114;-#100;-#101;-#114; sea level fluctuations -#102;-#114;-#111;-#109; Late br Jurassic to Early Tertiary. The main events recorded are; the regressive phase br at the contact between Masajid and Risan Aneiza Formations, Middle Turonian br regressive phase (Buttum Formation), the deeper conditions of Upper br Maastrichtian- Lower Eocene sediments in the eastern part of the area (Mitla br Formation). The main factors controlling the ramp deposition and the described br events are; structure control (Syrian Arc Deformation), eustatic sea level br fluctuations (combined with environmental influences such as autochthonous br carbonate productivity and siliciclastic supply) and paleorelief conditions.