The Bouguer gravity and magnetic RTP data were used to detect the depth of basement rocks in middle and south Diyala Province, east Iraq. The depth of the basement rocks was calculated by using the Source Parameter Imaging (SPI) method. New attempt is achieved to applied the SPI technique to the gravity values to estimate the depth of basement rocks. The depths of basement map derived from gravity data range 8-14 km, the depth of basement map derived from magnetic data range 9-13.5 km and the basement depth prepared by C.G.G, 1974 range 9-11 km. The derived maps from SPI method and that prepared by C.G.G, 1974 show good matching in the distribution of the depths of the study area. This study showed that basement’s depth range from 8-14 km with gentle increasing toward the east. A main basin trending NW-SE is found in the study area laying eastern Diyala river. It is believed this basin may contain hydrocarbon reservoirs.
The Bouguer gravity and magnetic RTP anomalies data were used to detect the main tectonic boundaries of middle and south of Diyala Province, east Iraq. Window method was used to separate the residual anomalies using different space windows for the Bouguer and Magnetic RTP maps. The residual anomaly processed in order to reduce noise and give a more comprehensive vision about subsurface lineaments structures. Results for descriptive interpretation presented as contour maps in order to locate directions and extensions of lineaments feature which may interpret as faults. The gradient technique is used for depth estimation of some gravity source which shows that the sources depth range between (13.65
... Show MoreThe depth of causative source of gravity is one of the most important parameter
of gravity investigation. Present study introduces the theoretical solve of the
intersection point of the horizontal and vertical gradients of gravity anomaly. Two
constants are obtained to estimate the depth of causative source of gravity anomaly,
first one is 1.7807 for spherical body and the second is 2.4142 for the horizontal
cylinder body. These constants are tested for estimating the depth of three actual
cases and good results are obtained. It is believed that the constants derived on
theoretical bases are better than those obtained by empirical experimental studies.
Gravity and magnetic data were used to study the deep crustal structures in Karbala and surrounding areas in central Iraq. The space window method was used to separate the residual from regional anomalies of gravity and magnetic data, the spaces of window are equal to 48,36 and 24 km. The Total Horizontal Derivative (THD) techniques and local wavenumber of gravity and magnetic are used to identify the faults and their trends with the basement rocks. The N45W, N45E, N-S and rarely E-W trends of faults are detected in the basement rock. It is believed that some of these faults extending from the basement to the uppermost layer of the sedimentary rocks.
Gravity and magnetic data are used to study the tectonic situation of Al-Kut- Al-
Hai and surrounding areas in central Iraq. The study included application of many
processing and interpretation programs. The window method with different spacing
was used to separate the residual from regional anomalies for gravity and magnetic
data. The Total Horizontal Derivative (THDR) techniques used to identify the fault
trends in the basement and sedimentary cover rocks depending upon gravity and
magnetic data. The identified faults in the study area show (NW-SE), (NE-SW) (NS)
and (E-W) trends. It is believed that these faults extending from the basement to
the upper most layer of the sedimentary cover rocks.
Basal breccia unconformity layer between Anah and Euphrates Formations in Al-Haqlaniyah area, Western desert, include enormous sinkholes and cavities usually cause severe damages to any kind of engineering facilities built over it. Two-dimensional resistivity imaging has been applied to detect the depth and extent of the subsurface caves at five stations. The dipole-dipole array is chosen with an electrode spacing of 2 meters. 2D Dipole-dipole imaging inverse models show the resistivity values have a big variation between the anomalous background resistivity of rocks and part of cavities. These models showed shallow cavities at 1 to 3 m depth and others at 5to 6 m depth and extending to a depth of 23 m. The unconformity layer
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The seismic reflection and gravity data were used to detect the tectonic boundaries in Kut-Hai-Fajir and surrounding areas, central Iraq. The depth maps of Dammam, Nhr Umr, and Sulaiy, formations were constructed and used to detect some boundareis in the study area. The residual gravity map and Total Horizantal derivative (THDR) also used to detected the tectonic boundaries. It is obtained that most boundaries or faults found in the deep formations; while some of them showen in the shallow fomations. The faults or boundaries obtained from gravity intrpretation mostly coincied with the deepest formation boundaries. Generally, the grvity anomalies conform the morphological feature locations within the depth maps of the formations. Many lon
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The gravity anomalies of the Jurassic and deep structures were obtained by stripping the gravity effect of Cretaceous and Tertiary formations from the available Bouguer gravity map in central and south Iraq. The gravity effect of the stripped layers was determined depending on the density log or the density density obtained from the sonic log. The density relation with the seismic velocity of Gardner et al (1974) was used to obtain density from sonic logs in case of a lack of density log. The average density of the Cretaceous and Tertiary formation were determined then the density contrast of these formations was obtained. The density contrast and thickness of all stratigraphic formations in the area between the sea level to t
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The resistivity survey was carried out by using vertical electrical sounding (VES) and 2D imaging techniques in the northern Badra area, Eastern Iraq. Eleven VES points distributed on two parallel profiles and six 2D imaging stations were applied using long survey lines.
In general, two types of aquifers are recognized in the study area. The first is the Quaternary aquifer, which appears in all geological sections and inverse model of 2D imaging stations (2DS).This aquifer can be divided into upper and lower aquifers as shown in (2DS1), (2DS3), and (2DS4). Generally, the thickness of this aquifer ranges between (30-200 m) which occurs at a depth of (10-30m) according to geological sections, while its thickness ranges between (35-180m)
Tectonically, the location of the Al-Ma'aniyah depression area is far from active boundary zones, their tectonic features have to reflect the original depositional environments with some horizontal movement due to rearrangement of the basement blocks during different actives orogenic movements. So, the analysis of aeromagnetic data were considered to estimate the thickness and structural pattern of the sedimentary cover sequences for this area. The aeromagnetic data, which are derived from Iraqi GEOSURV to Al-Ma′aniyah region is analyzed and processed for qualitative and quantitative interpretations. The process includes reducing the aeromagnetic data to pole RTP, separation the aeromagnetic data to regional an
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