الفهرس 
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Abstract
The study area is located in the southwestern Gulf of Suez, Egypt, between lat. 27ْ 50’ N & 28ْ 18’ N, and long. 33ْ 09’ E & 33ْ 40’ E. This area covers the Morgan Accommodation Zone (MAZ), the southernmost part of the central Belayim dip province and the northern part of the Amal-Zeit dip province. The western sub-basin (WSB) of this area was studied in detail; while the eastern sub-basin (ESW) was not studied in detail due to the missing data. This work deals with the stratigraphy, structure and the facies analysis of the Miocene succession of the WSB in order to deduce the successive depositional and tectonic evolution of the concerned succession in relation to the different sequential events that affected this sub-basin.
Seismic-facies analysis and the subsurface tectonic evolution of the WSB were studied by seismic reflection data of 45 seismic lines. Eight of these lines were selected to illustrate the structural framework and depositional history of the WSB which was supported by the composite, velocity and vertical seismic profile (VSP) logs of ten wells (GC48-14, ERDEMA-1, GB84-6, GS334-2, NN88-1, NN89-1, ERDMA-2, SB374-2C, S. RAS EL USH-1 and W. ASHRAFI-1X). The analysis of the structure two way time (TWT) contour maps and rose diagrams revealed that the Miocene strata are dissected by two main fault trends. The first is the listric normal faults which trend in a NW-SE direction (Clysmic trend), while the second is a NE-SW trending oblique-slip cross faults (of smaller lengths and less density) running nearly perpendicular to the Clysmic faults and reflecting the Morgan Accommodation Zone (MAZ). North of this zone, a general dip towards the northeast is recognized, south of this zone, the regional dip is towards the southwest. The complex structural framework was the main factor controlling facies changes of the syn-depositional Miocene units along the study area.
The lithostratigraphic studies helped in the recognition of the Miocene rock units of the study area. These units, from base to top, are as follows: Rudeis Formation, Kareem Formation, Belayim Formation, South Gharib Formation and Zeit Formation. The planktonic foraminiferal and calcareous nannofossil species of the Miocene succession were also investigated and enabled to construct the biostratigraphical zones which were matched well with those in the standard biostratigraphical scheme. Moreover, the depth contour maps, isopach maps, lithofacies maps and velocity maps for the Miocene succession of the WSB were constructed.
The information obtained from well data, seismic velocity analysis, structural investigation and seismic facies analysis has enabled to classify the Miocene succession into two major 3rd order depositional sequences. The first sequence is represented by the Lower-Middle Miocene rocks, including the Rudeis and Kareem formations. The top of this sequence is bounded by the depositional sequence boundary (DSB1), while the base of this sequence can not be followed on the seismic sections because they are badly processed. The second sequence is represented by the Middle-Upper Miocene rocks, including the Belayim, South Gharib and Zeit formations. This sequence is bounded between the depositional sequence boundaries (DSB1 & DSB2). Furthermore, the Kareem Formation was divided into two 3rd order genetic sequences based on the biostratigraphic data, facies analysis and the main logs (GR, resistivity, sonic, density and neutron) of 11 wells (GC84-14, LL87-3, ERDMA-1, GB84-6, GS334-2, NN88-1, NN89-1, AMAL-10AST, AMAL-8, S. RAS EL USH – 1 and W. ASHRAFI-1X).