الفهرس 
ABSTRACTOnly 14 pages are availabe for public view
 |  | from | 143 |  |  |
| | | from | 143 | | |
Abstract
The studied area lies in the central part of the western desert of Egypt south El-Dakhla
Oasis; it is limited by the latitudes 24 to 25 N and the longitudes 28 to 30 E.
The aim of the present study is to obtain the basement topography, and to evaluate the
surface and subsurface tectonic pattern in the studied area and consequently their effect on the
sedimentary cover. In order to achieve this goal, the present study depends mainly on the
following:
A. The aeromagnetic map of the study area (scale 1:500,000) prepared by ”La Champaigne
General De Géophysiques” for EGPC and CONOCO (1977).
B. The geological map of Egypt (scale 1:500,000) published by EGPC and CONOCO
(1987). This map was used to delineate the surface structural lineaments and the
geological rock units.
C. The available processing software.
D. Published geological and geophysical studies on and around the studied area.
The aeromagnetic map of the studied area was used to construct the reduced to pole
(RTP) magnetic map to remove the inclination effects of magnetic field, where the spatial
location of each anomaly located approximately over the causative body, The first vertical
derivative (FVD) magnetic map was also prepared from the RTP map to magnify the effect of
the smaller and the shallower structures with respect to that of large scale features characterizing
deep sources.
Apparent magnetic susceptibility values has also been calculated and plotted as a
contour map to delineate the subsurface distribution of different rock units rich in magnetic
minerals.
The downward continuation (DWC) magnetic maps at different subsurface levels were
prepared from the RTP map to follow the subsurface structure at levels near to sources.
The qualitative interpretation of the aeromagnetic data includes the following:
ABSTRACT
x
Description of the different magnetic maps; the aeromagnetic map, the RTP map, the FVD
map , the DWC maps., and finally source edge detection technique (SED)
The description of the anomalies involves their shape, amplitude, extension and gradient.
the SED map description involve gradient direction and whether the symbols coincide with
anomalies or not ,which is fulfilled in the study
The quantitative interpretation of the aeromagnetic data involves the basement depth
estimation by applying different techniques.The used techniques are; the 2-D avearaged power
spectrum .
The Natural spectral analysis technique, the 3-D Euler deconvolution ,the 3-D analytical
signal ,and source parameters imaging. The depth values computed by the different methods
didn’t show larg difference, and generaly, the computed basement depths rang between 450 and
2000 m.
The surface structural trends were traced from the geological map of Egypt
(CONOCO,1987). The most important surface structural trends are ,the ENE-WSW ,the NE-SW
,the E-W and the N-S trend, the study area lies withen the stable shelf of Egypt (youssef, 1968)
The subsurface structural trends (magnetic trends) were traced from the RTP, FVD and
DWC maps. The main structural trends deduced from the magnetic maps of the studied area are
,the E-W ,the N-S ,the NE-SW ,and the NW-SE trends.
The results of both qualitative and quantitative interpretations are combined to get the
general view of the subsurface structures in the area and its relation to general tectonics.