الفهرس 
INTRODUCTIONOnly 14 pages are availabe for public view
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Abstract
El Farafra area is located in Central Western Desert of Egypt,
between latitudes 26 30 to 28 05 N and longitudes 26 50 to 29
00 E. Covering 37000 square km (approximately, 23700 line km).
The geologically area is covered by various sedimentary rocks range
in age from Late Cretaceous to Eocene. In addition to, some
quaternary sand dunes oriented in the N-S direction
The distribution of gamma-ray spectrometric data were used
to help identify zones of consistent lithology and contacts between
contrasting lithologies. The observed radioelement zones show a
fairly close spatial correlation with the geologically mapped
lithologics. It was qualitatively interpreted and differentiated into
sixteen various interpreted spectral radiometric lithologic unit
(ISRLU) zones, which describe different spectral radioactivity
levels. The high values (bright color) denoted as Esna Formation
(Tpe), Dakhla Formation (Kud), and Bahariya Formation (Kub).
Meanwhile the low values (black color) denoted as sand dunes and
Quaternary.
The ISRLU zones are highly correlated with surface geologic
map and very highly correlated with surface of the false-colour
Landsat Satellite Multispectral Scanner (MSS) photomap. As it has
been mentioned before that the eU and eTh leads is distributed in
the radioelement leads map as follow: Uranium Leads: Anomalies
are donated on the ISRLU map as red color. Thorium leads:
Anomalies are donated by green color on ISRLU map. Potassium
leads: Donated as blue color on the ISRLU map. These anomalies
are considered to represent the first priority for ground geological,
geophysical and geochemical follow- up.
The natural radiation (exposure rate) of the study area is
frequently referred as a standard for comparing additional sources of
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man-made radiation such as atomic weapon fallout, nuclear power
generation, radioactive waste disposal, etc. Furthermore the dose
rates from the terrestrial gamma-radiation range from 0.0 to 2.2
mSv/y. The values between (0-1) remain in the safe side and the
values between (1-2.2) should be subjected for further follow up
investigations.
Various techniques, including reduction to the pole (RTP),
power spectrum, filtering and magnetic depth calculation were
applied to the aeromagnetic data. Integration of such techniques has
yielded a basement tectonic map for the study area, which shows
that the main Wadis in the study area are structurally – controlled.
The Three techniques of magnetic depth calculation were
applied in the study area. The first glance of these maps shows that
the Source Parameter Image (SPI) and Analytic Signal (AS) results
are very closed to each other. Meanwhile, the Euler method divided
to two maps residual and regional they show the same major
features. The magnetic depth maps show large basement structure
high (swell) colored by red color. The average depth of the swell is
reach 200m, 220m, 800m in SPI, AS, and EU respectively. This
swell is bounded by two basement structure low (trough) marked by
blue color. The average depth of the trough reach 6800m, 7200m,
7000m in SPI, AS and EU respectively. These maps of the depths
help us very much in delineate the general structures of basement
surface. To confirm the interpreted magnetic basement tectonic
framework of the studied area, a magnetic profile was modeled
using Five 2D- modeling technique. Close examination of this
profile shows an excellent fit between the observed and calculated
anomalies with an errors reach 0.34 nT, 0.17 nT, 0.35 nT, 0.42 nT
and 0.28 nT.