كلية النفط والمعادن

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COASTAL GEOTECHNICAL PROPERTIES AND - PILLING FOUNDATION DESIGN, AREA BETWEEN PORT — SUDAN AND SAUKIN RED SEA, SUDAN
(Al Neelain University, 205-08) OMAR ATTAJ OMAR AL-IMAM
A combination studies had been done to put the area under investigation in focus for the future population pressure and economical development activities in engineering planning view. All the data was processed by Rock Ware 2002 , 2004 and Auto Cad in 2D, 3D models. This study including very important infonnations about the area such as geomorphologic features, hydrological process and marine conditions. The geological setting shows different geological environments such as sabkhas, salt marshes and transitional zone between land and marine environments. Coral reef, shoreline conﬁguration and continental shelf were studying from a geological point of view included onshore sites. Stratigraphically, Port-Sudan region consist of four layers, Dama Dama two layers and Saukin characterized by unhomogenatic stratigraphical formation. Two facies forming the stratigraphy sequences on the continental shelf which are residual soil and coral reef limestone. The later one was classiﬁed in all sites by weathering grade. The study shows that the area is rich in raw building materials which characterized by good chemical, physical and geotechnical speciﬁcations. Sand, gravel, building stones and carbonate limestone were tested for grain size distribution, densities, Califomia bearing capacity, aggregate test, crushing value, impact value, point load and unconﬁned compressive strength. The geochemical analysis of subsurface soils and intruded sea water covered all the hazardous cations and anions and clariﬁed the interaction between them.
Geophysical Study on Groundwater Structure at two localities in Central Butana (Sudan)
(Neelain University, 2001) Khalid Mustafa Kheiralla.
ABSTRACT The study area lies between latitudes 14° 30‘ and 16° 00‘ N, and longitudes 33° 30‘ and 35° 30‘ E. A negative Bouguer gravity anomaly was identiﬁed in the area and referred to as Jebel Mundara. Also the drainage system shows the anomaly area as a delta of four Wadis (valleys). A number of isolated outcrops of l?re-Cambrian Basement Complex rocks scatter over the central plains of Sudan. In the Butana region, several hills occur prominent landmarks within the predominai;ttly ﬂat clay plains. The solid geology of the Butana plain is rather concealed under a feneer of variable thickness of superﬁcial clays covering over 70% of its total area. The present study was suggested in an effort to delineated and deﬁne the mentioned anomaly in more detail and to give a reasonable geological and hydrogelogical exploration for its existence. Also to check the delta of another four Wadies lying on the opposite side and shearing the same water divide with the mentioned ones. Integrated geophysical methods (Regional Gravity, EM Survey, and Electrical-Sounding) were applied to achieve the above aims. A total of 100 gravity points were conducted in the study area and they are compile to 275 gravity points acquired, by Sun Oil Company (approximately 2475 krnz were covered in the study area). Gravity data analyses were perfonned by "GEOSOFT" packages. The results show that the gravity lows is largely attributed to the occurrence of low-density rocks (granite intruded) into the high-density rocks (green schist) of the Butana region. On the other hand the gravity high zones unambiguously coincide with the areas of known shallow Basement Complex. A total of 57 VES were carried outs in the study area and distributed a long 7 proﬁles, cover almost the two interested areas. The results indicate‘ that the sedimentary cover'is relatively thin, and the Basement Complex is‘very shallow in the study area. The total length of the EM Survey is about 35 km. The EM measurements reﬂects considerable fracturing (faults and shear zones). Threc sets of fractures are identiﬁed with NE, NW and N-S trending. ' Finally, one of the objective of this work is to delineate lineaments in more details using geological informations and the geophysical data (gravity, resistivity, and electromaghetic) in the study area. They are also merged and combined with image data for a given geographic area using "GIS" software, to produce an integrated map of the area. Water supply'for settlement in the study area requires a different approach. The Basement rocks outcrop on the surface and the area is sloping to the north, therefore, seepage of water through the fracture system is negligible, in this case storing of rainwater through surface dams is more appropriate. ll
Geology and Potential Economic Georesources of El Jebelein Area — White Nile Willayia - Sudan
(Al Neelain University, 2001-03) Mohammed Yahya Abdelgalil
This study was carried-out in El J ebelein area-southeastern part of White Nile Willayia-Central Sudan. Setting and regional geological map, prospecting and exploration of building rocks and industrial minerals are the main objectives of the study. Fieldwork followed with laboratory investigation including petrographic, geochemical and geostatistical analyses were the methods adopted in this research. The geology of the stu_dy area is composed of polymetamorphosed and multi-deformed Basement Complex rocks, which is consisting of older gneisses and rnigrnatites of the hi glr-grade arnplribolite facies. They were overlain by rnetasediments of low-grade greerrsclrist facies. Grantoidal rocks intruded both of these units. Reminants of Upper Cretaceous sandstone overlain by Umm Rrrwaba Formation are preserved in basement troughs. The whole area, is covered by Quaternary Superﬁcial deposits. Chemical analysis of the carbonate rocks _in four out of ﬁve localities proved them to be suitable for potential Portland Cement Industry with raw mix of the two components: clay and limestone, with a Lime Saturatin Factor (L.S.F) =96. Using arithimatic mean method for reserve estimations of marble deposits. Four sites (I, ll, III and IV) in Naﬁrr are ﬁguring approximate potential Calcium Carbonate of 36, 20, 45 andl8 million tons, respectively. The discovery of gossans has encouraged carrying a geochemical prospecting in the suspected localities. Revealed trace elements anomalous content of element suggests gossan secondary minerlization, which may be reﬂected to primary massive sulphides of polymetallic nature (Ag, Pb, Zn, Cu, Co, etc.). The geological and tectonic natures of 'tlre study area suggest that the area belong to older crustal rocks with srrpracrustal metasedimentary rocks. Shear zones are responsible for showing of sulphide mineralization. ‘Morphological clraracteristics, the physical-meclranical tests and nice appearance of granite and marble in the study area encourages quarrying of decorative and dimension block stones.
HYDROCHEMISTRYOF GROUNDWATER IN KHARTOUM STATE CENTRAL SUDAN
(ALNEELAIN UNIVERSITY, 2002-02) Hussien Salim Awad
Abstract The groundwater chemistry of Khartoum State between longitudes 32° 00'-33° 0O’E and latitudes 15° O0’-16° 00'N was evaluated and assessed using different hydrogeological methods. Groxmdwater in the region occurs in two hydraulically interconnected aquifers. The siliciclastic sediments of the Cretaceous Omdurman Formation form the lower one, and the mostly unconsolidated sediments of the Cretaceous-Tertiary- Quaternary Umm Ruwaba Formation comprise the upper one. The evaluated hydrodynamic properties revealed unconﬁned conditions in most parts of the aquifers system and partial conﬁnement in some parts, where clayey zones occur. The analysis of ﬂow system indicated a regional flow direction towards the northwest, with a local ﬂow regime towards the east. Preliminary assessment of grormdwater chemistry was investigated by using different statistical technique such as X-Y plots, correlation, cluster, principle components, and factor analyses. The results of analyzing data by these techniques showed negative correlation between the exchangeable ions, Na-Ca and Na-Mg, which means ion exchange process is active. The strong correlations among Na’ and Cl‘ ions, TDS and EC indicate that salinization is related to the increase of concentration of these ions. Dissolution process of evaporitic mineral is suggested by the strong positive correlations between Ca”, Mg” and SO42" Groundwaters were classiﬁed by -grouping them‘ into faeies~ For ~the—purpose of -classiﬁcation, the pattern diagram of Lee, trilinear plots of Hill-Piper, Durov and by Chadha diagram. Three main types of hydrochemical facies were recognized, Ca-Mg-HCO,, Ca-SO,-HCO, and Na-Ca-S04-Cl. The spatial distribution of these facies and hydrochemical sections, indicate that the anionic facies changes in the ﬂow direction from HCO,’ to SO42’ and ﬁnely to Cll. The cationic facies is mostly affected by ion-exchange process of calcium and magnesium by sodium. Mixing is an important and active process that has affected the water facies in the region. The saturation state of groundwater showed that, it is saturated with respect to carbonate minerals and undersaturated with respect to CO2 and sulphate. Assessment of groundwater quality at different locations indicated its suitability for all purposes except at few speciﬁed localities.
Resistivity and Self-Potential InvestigationsOfSubsurface Water Seepage PhenomenonAt Omdurman
(ALNEELAIN UNIVERSITY, 2002-08) Mohsin Ali Elhag Fahal
ABSTRACT The Omdurman subsurface water seepage problem constitutes a serious phenomenon at present because of the high- density population and lavish use of water. The Omdurman region is covered by rather ﬂat Cretaceous Nubian sandstones with gentle centripetal dips that hinder the outﬂow of the groundwater into the River Nile. The sandstone bands are intercalated with mudstone layers or lenses, and injected by Tertiary basalts along the bedding planes. Both rock types are impervious and retard the inliltration of the surface water, hence over-ﬂooding. Plastic clay soil (Banat east, Al- Abassia and AL-Ahlya square) when present may also hamper vertical water seepage, cause swelling potential and consequent damage. Geophysical investigations applying resistivity and selt potential (SP) methods are conducted to reveal the occurrence and distribution of the impervious layers underneath, and to detect the location and characteristic features of the subsurface streamlines. The results obtained indicate the presence of signiﬁcant almost horizontal bands and lenticular bodies of mudstone intercalated with the sandstones of the Nubian formation. Some of these bands are situated close to the land surface e.g. at Bait- Almal, Al-Mulazmean, A1-Busta, Banat east and Al-Arda l districts. These layers have been successfully delineated by the electrical resistivity method. Geo-electrical sections and maps were constructed to show their locations, thicknesses, attitudes and inclinations. The mudstone layers being impervious prevent water inﬁltration from natural and artiﬁcial sources and can therefore, create temporary perched aquifers located at the interface between the superﬁcial deposits and the top very layer or lens of the mudstones. From these aquifers water is expected to rise up and seep into the surface land and cause damage. Negative SP anomalies show the occurrence and variable intensities of the subsurface streamlines. The distribution of the SP contour lines indicate the haphazard orientation of water ﬂow, hence, the phenomenon appears to be of local nature. 2
THE MAGNETIC FIELD GENERATED BY TWO ELECTRONS BOUND IN SOME ANGULAR MOMENTUM EIGENSTATES
(Al Neelain University, 2003-03) AMANI SALAH MOHAMMED
Application of a direct general method for calculating the magnetic ﬁeld gen- erated by two electrons bound in angular momentum eigenstates is presented, illustrated and applied to the ground states of the tripositive ions Pr“ and V3+. The ground state wave functions are written as a four components spinor and the operators for‘ the orbital current and spin densities as a 4 >< 4 matrices. Analytical expressions for the expectation values of these opera- tors are presented by making use of hydrogenic wave function. The resulttent expressions of the current densities are substituted in the components of the magnetic ﬁeld which gives unexpected results.
The Hydrogeology Of Jebl Mara Area With Special Emphasis On Water Quality,Western Sudan
(Al Neelain University, 2004) Sami Hashim Mohamed Mahmoud
The study area situated between longitude 24°.00'—25°.00' east and latitude l2°.30' and l4°.OO' north. The aim of the study is to cover the geology, hydrology with special emphasis on water quality (qualitative and quantitative). A ﬁeld work was carried out several times to the study area as to collect water samples and ﬁeld observations. Water samples from hand pumps, dug wells, wadis and hot springs were collected from the area in dry and wet season. Physical, chemical, and bacteriological analyses were done in different laboratories by applying standard methods given by A.P.H.A., and A.W.W.A., standard methods. Major cations, some, some trace elements and other water properties were examined for all samples in three recognized laboratories. Seasonal variation (dry & wet) of physico-chemical properties major cations, major anions, some trace elements shown by drawing seasonal variation graphs and aerial distribution maps of all elements. A comparison between water from wadis and hot springs was also done. The study revealed that samples from wells (hand & dug) consists of variable concentrations of ions all of them fall within the permissible limit given by Word Health Organization (W.H.O., 1984) except manganese, total iron zinc concentration were high and above the recommended values. Great deﬁciencies of iodine were detected throughout the study area (low or nil values) in all samples taken. About 95% of samples from wells (hand and dug) classiﬁed as Calcium-Sodium-Bicarbonate-Chloride type, and 5% as Calcium—Magnesium-Bicarbonate-Chloride type .
Evaluation of the Coastal Plain Aquifer Physical Parameters in Gaza Strip
(Al Neelain University, 2005) Samir Khalil Shaath
Gaza Strip like some other parts of the Middle East countries has distinct and serious deﬁcit in water. Currently, there is a water sholftag problem for most of the Gaza Strip’s residents. The quality of consulmfed water has very grave problems, as some bacteriological contamination, lasl well as increase in nitrates and chlorides to levels which already have been above the safety limit. Further more it is forecasted that the quantity of available water, which is already scarce, may drop to incompatible levelsl with an acceptable standard of living, public health, social and economid development in the region. To solve the quantity shortage problem in Gaza Strip, correct data about the physical aquifer parameters should be available. Si-ace; hydrogeological studies about Gaza Strip aquifer are not available; an' accurate scientiﬁc research will present the basis of figuring the aquifer parameters, which may help in calculating the amount of stored water in the aquifer and can be performed in the lield by either direct method, or by indirect method. Every aquifer has its own physical parameters (Characteristics), as Porosity (E), Transmissivity (T), and Storage Coefﬁcient (S), these physical parameters control the ﬂuids passage through the aquifer. To study any aquifer, we must calculate the aquifer phvsical parameters by executing some tests and analyze their results, from these tests the. pumping test can be used. The aim of this research is to ﬁnd some physical characteristics for; the Coastal Plain Aquifer in Gaza Strip. as values for Transmissivity (T) and Storage Coefficient (S). l I This study showed that, the water quantity is decreasing year after year, and the quality of water is in continuous deteriorating. There are some suggestions to increase the water quantity in the reservoir, and it is recommended to decrease the usage of \vater and use the water wisely.
The Geology and Structural Evolution of the Area Around the River Nile Between /lthara and Ahidiya, Nile State, Sudan; Remote Sensing, Structural and Geochemical Approaches.
(Neelain University, 2005) Esam Aldeen Ali Mohammed Ahmed
ABSTRACT The study area covers 8100 Kmz in north central Sudan bounded by Latitudes 17° 50‘- 18° 30‘ N and Longitudes 33° 40‘ and 34° 30‘ E. Different digital image processing techniques applied to enhance the geological and structural details of the study area, using Landsat Thematic Mapper (TM) and Enhance Thematic Mapper (ETM 7). The (ETM+) images show that the southeast trending structural lineaments of the Nakasib Suture Zone (N SZ) continue to the southeastern part of the Bayuda Desert north of Atbara. Geologically, the area is underlain by highly sheared maﬁc-ultramaﬁc rocks, volcanosedimentary sequences and supracrustal metasediments. All of the units are invaded by calc-alkaline and post to anorogenic intrusions. The maﬁc-ultramaﬁc masses have all the features characteristic of ophiolite suits including layered cumulate, sheeted dolerite dykes, pillow lavas section and associated deep marine sediments, but are dismembered and recrystallized. The pillow lava sections have typical mid-oceanic ridge basalt geochemical signature as indicated by discriminate diagrams. The ophiolitic massifs identiﬁed in this work have been grouped into three complexes, namely Sotrebab, Qurun and El-Fadlab complexes forming discontinues NE-SW trending belt that merges with the ophiolitic fragments along the Nakasib Suture Zone. Therefore, these complexes may represent the southwestern continuation of the Nakasib Suture Zone. The volcanosedimentary sequence is comprised of turbidities besides massive volcanic ﬂows which have been recrystallized in the condition of the greenschist facies of regional metamorphism. They have predominantly tholeiitic to mild calc- alkaline geochemical afﬁnity, thus suggesting subduction related geotectonic setting. XIII
Geochemical Studies and Tectonic Control of Gold Mineralization in the Bayuda Desert, Northern Sudan with Especial Emphasis on Hagaggia Area
(Al Neelain University, 2005-01) ELSAYIED RABEH SALIH
The study area is located in the northern sector of the Sudan; at the western side of the River Nile. Geotraverses and laboratory examinations indicate that the area comprises different Lithological Lmits; high-grade gneisscs, Volcanosedimentary sequences intercalated with minor intrusions (quartz veins, dykes and amphibolite bands). The tectonic boundary that separates the high- grade rocks ﬁ'om the low-grade rocks is a thurst boundary as conﬁnned by petrographic descriptions of the rocks. The study area is subjected to multiphase of deformation, the evidence for this deformation, which has been seen in the area, includes folding, faulting and shearing, in addition to microscopic evidence. Low-grade rocks (sercite-mica schist, muscovite schist), and calcsilicate host the sulphides and associated gold elements, in addition to diorite and felsite dykes). The sulphides minerals and gold deposit are controlled by major deformation zone. The gold occurrences in the area seem to be situated in brittle- ductile structure that formed as the result of extensional shear deformation. The geochemical samples for gold prospecting and its associated elements include stream sediments, residual soil and rock chip samples. The soil samples were collected from the B-horizon, prepared and ﬁnally analyzed for Au, Ag, Zn, Pb and Cu.The results obtained revealed that, the effective use of stream sediments and soil samples for detecting gold mineralization. The discrimination diagrams indicate that, the rocks of the study area are of volcanic arc tholeiitic and calc-alkaline setting, which were probably formed at ﬁrst stage of subduction and island arc.
Geochemical Studies and Tectonic Control of Gold Mineralization in the Bayuda Desert, Northern Sudan with Especial Emphasis on Hagaggia Area
(Al Neelain University, 2005-01) ELSAYIED RABEH SALIH
The study area is located in the northem sector of the Sudan; at the western side of the River Nile. Geotraverses and laboratory examinations indicate that the area comprises different Lithological units; high-grade gneisses, Volcanosedimentary sequences intercalated with minor intrusions (quartz veins, dykes and amphibolite bands). The tectonic boundary that separates the high- grade rocks from the low-grade rocks is a thurst boundary as conﬁrmed by petrographic descriptions of the rocks. The study area is subjected to multiphase of deformation, the evidence for this deformation, which has been seen in the area, includes folding, faulting and shearing, in addition to microscopic evidence. Low-grade rocks (sercite-mica schist, muscovite schist), and calcsilicate host the sulphides and associated gold elements, in addition to diorite and felsite dykes). The sulphides minerals and gold deposit are controlled by major deformation zone. The gold occurrences in the area seem to be situated in brittle- ductile structure that formed as the result of extensional shear deformation. The geochemical samples for gold prospecting and its associated elements include stream sediments, residual soil and rock chip samples. The soil samples were collected from the B-horizon, prepared and fmally analyzed for Au, Ag, Zn, Pb and Cu.The results obtained revealed that, the effective use of stream sediments and soil samples for detecting gold mineralization. The discrimination diagrams indicate that, the rocks of the study area are of volcanic arc tholeiitic and calc-alkaline setting, which were probably formed at ﬁrst stage of subduction and island arc.
Sedimentological and Geochemical Characteristics’ of the Sediments West of Al Bauga Area, River Nile State, Sudan
(Al Neelain University, 2005-02) Hamed Basher Osman Hamed
The study area lies about l O0 km n orth ofAtbara town in the River Nile State, in the central north of the Sudan, and located between latitudes 18° 00/ and l8" 18/ N and longitudes 33° 38/ and 33° 57/ E with an extending area about 300 kmz. The aim of the study is to determine the sedimentological, geochemical and hydrological characters to clarify the depositional palaeoenvironment. Four surface vertical proﬁles were examined in the field and several techniques were applied including grain size analysis, thin sections, x ~ ray diffraction, infrared spectroscopy, x — ray ﬂuorescence, atomic absorption spectroscopy, spectrophotometer and water analysis. The lithofacies analysis of the Al Bauga sediments reveals seven facies types on the basis of their lithology, grain size and sedimentary stmctures. The depositional environments are including three different sedimentary facies sequences, ﬂuvio-lacustrine, aeolian and ﬂuvial sediments. Texturally most of the sandstones of Al Bauga sediments are medium grained, poorly to very poorly sorted, and ﬁne skewed very leptokurtic with unimodal and bimodal size distribution. The grain size parameters coupled with the observed sedimentary structures indicated that the sandstones of Al Bauga sediments have been deposited in both ﬂuvial and aeolian environments. The sandstones of Al Bauga sediments are characterized by a high concentration of SiO2 and are dominantly quartz arenite including a percent of suture polycrystalline quaitz and epidote which reﬂects an increased mineralogical maturity and indicated metamorphic source rocks. Clays are dominantly detrital kaolinite which suggested tropical humid paleoclimate. The lower part of Al Bauga sediments contains black phytoclast (black wood) high concentration of Sr and relatively high content of organic matter which suggested that these sediments were deposited under oxidizing condition in ﬂuvial e lacustrine environment nearby the source area. The sediments sequence of the Al Bauga sediments is divided into ﬁve geochemical units using bulk geochemistry, especially those of iron, manganese, calcium and potassium. The unit boundaries are correlated with the signiﬁcant lithologic boundaries. From the chemical data for groundwaters it is evident that the chemistry of groundwater from the region of Al Bauga sediments is controlled by the chemical and mineralogical composition of both the basalts and the basement rocks and the waters are medium to high saline. The groundwaters in the Al Bauga sediments area show the dominance of Ca+Mg,Na+K cations hydrochemical facies and HCO3,Cl+CO3 anion hydrochemical facies.
Geophysical Exploration for Groundwater in Crystalline Rocks, El Obeid Area, North Kordofan, Sudan
(Alneelain University, 2005-04) Abd El Rahman Ahmed Abbashar
The study area lies between latitudes 13° 22’ and 13° 05’ North and longitudes 30° 20’ and 30° 12’ East. The geology of the study area comprises the superﬁcial deposits of Qoz sand, sands of different grain size, sandy clay, clay and silt overlie the Basement complex rocks. The Basement complex rocks consist of gneiss, quartzite, schist, granite and pegmatite. This type of geological formation is recognized as a poor aquifer for occurrence and accumulation of groundwater. Only in certain circumstances water may exist; that is in the presence of geological structures like fractures, joints, cracks faults.... Etc. The water quantity depends on resistivity of rainfall and inﬁltration in the study area. - In the current study geophysical techniques (electromagnetic and resistivity) were conducted to investigate the groundwater occurrence in the area. Ten electromagnetic proﬁles of total length 11.5 km, were conducted in the study area. The measurement reﬂects considerable fracturing, faults and cracks trending in North-South direction parallel to the streams or Wadis channel. ' Seven horizontal electrical resistivity proﬁles of total length 4.3 Km were carried out in the study area to locate anomaly sites and to verify the measurement done by electromagnetic proﬁles. These resistivity measurements insure the viability of locating sites by using the electromagnetic methods by giving better results in delineation of Basement rock structures. \ Finally ﬁfteen vertical electrical soundings were applied in the study area in the center of the anomaly that shown by conduction of electromagnetic and electric resistivity proﬁles. These VES results conﬁrm the result depicted by electromagnetic and electric resistivity proﬁles and, show depth to fresh Basement rock more than 54 meter in Kurbage locality, 77 — 135 m in El Sunut locality and 69 — 75 m in Jebel Kordofan locality which is a best locality compared to other two localities ( Kurbage and Elsunut ) in term of water quantity, quality and depth to water.
Elemental Constituents of Crude Oil, Formation Water, and Source Rocks in Muglad Basin - Sudan
(Al Neelain University, 2005-08) Rahmat Alla Hassan Saeed Babiker
This study had been done on the elemental constituents of the oilﬁeld water, crude oil, and the source rocks in Muglad basin using the atomic absorption spectroscopy (AAS) technique in order to ﬁnd out the source of trace elements found in crude oil and to evaluate the quality of Sudanese crude oil on the basis of the concentration of trace elements, which have adverse effects on the speciﬁcations of the crude oil. Twenty four representative samples of different types were collected from different sites and tested for detemnnation of concentration of the elements: Ca, Mg, Na. Cu, Co, Ni, Zn, Pb, Cd, and Fe. The evaluation of the data obtained, for the concentration of these elements, had been done by applying non-parametric test to ﬁnd out the p-values in order to prove whether these results are statistically signiﬁcant or not. All the p-values obtained were found to be less than 0.05, which indicate that all tests, carried out through this work, are statistically signiﬁcant. By comparison of elemental constituents of Sudanese crude oil, regionally with Libya crude oil and intemationally with Venezuela, Califomia, and Canada crude oils, it was found that the Sudanese crude oil contains the lowest concentration of some harmful trace elements like nickel (Ni) and lead (Pb) which can verify its quality. Also it was found that the concentrations of the elements under study show very high values in case of source rocks, which indicate that the source rocks can be considered as the main possible source of trace elements, found in crude oil. The element cadmium (Cd) was not detected in all samples of the source rocks, which had been analyzed for determination of trace elements, because of its low concentration in the earth crust (0.2- 0.5ppm).
The Geology and Structural Evolution of the Area Around the River Nile Between Atbara and Abidiua, Nile State, Sudan} Remote Sensing, Structural and Geochemical Approaches.
(Al Neelain University, 2005-09) Esam Aldeen Ali Mohammed Ahmed
The study area covers 8100 Kmz in north central Sudan bounded by Latitudes 17° 50‘- 18° 30‘ N and Longitudes 33° 40‘ and 34° 30‘ E. Different digital image processing techniques applied to enhance the geological and structural details of the study area, using Landsat, Thematic Mapper (TM) and Enhance Thematic Mapper (ETM 7). The (ETM+) images show that the southeast trending structural lineaments of the Nakasib Suture Zone (NSZ) continue to the southeastem part of the Bayuda Desert north of Atbara. Geologically, the area is underlain by highly sheared maﬁc-ultramaﬁc rocks, volcanosedimentary sequences and supracrustal metasediments. All of the units are invaded by calc-alkaline and post to anorogenic intrusions. The maﬁc-ultramaﬁc masses have all the features characteristic of ophiolite suits including layered cumulate, sheeted dolerite dykes, pillow lavas section and associated deep marine sediments, but are dismembered and recrystallized. The pillow’ lava sections have typical mid-oceanic ridge basalt geochemical signature as indicated by discriminate diagrams. The ophiolitic massifs identiﬁed in this work have been grouped into three complexes, namely Sotrebab, Qurun and El-Fadlab complexes forming discontinues NE-SW trending belt that merges with the ophiolitic fragments along the Nakasib Suture Zone. Therefore, these complexes may represent the southwestem continuation of the Nakasib Suture Zone. The volcanosedimentary sequence is comprised of turbidities besides massive volcanic ﬂows which have been recrystallized_in the condition of the greenschist facies of regional metamorphism. They have predominantly tholeiitic to mild calc- alkaline geochemical affinity, thus suggesting subduction related geotectonic setting.
Digital Image Processing of Landsat7 data and GIS Application for Geological Investigation in Jebel Erba Area, Red Sea Hills, NE Sudan A
(Neelain University, 2006) Ibrahim Ahmed Ali Babikii"
ABSTRACT Digital image processing and Geographic Information System techniques, together with a limited reconnaissance ground truthing, have been used to investigate the geology of the area around J. Erba and J. Oda of the Sudanese Red Sea Hills (RSH). The methodology fulﬁlled and the procedures followed during this study enabled the establishment of geodatabase named GeoRSH and the production of two geological maps of scale 1:2§0,000. The area of study occupies the central part of RSH of Sudan that belongs to the Nubian Sector of the Arabian-Nubian Shield (ANS). It forms part of the Gebeit terrain that is known to be created among the other four terrains of NE Sudan (Tokar, Heya, Gabgaba and Gert) during the Pan-African event (950-500Ma) due to subduction-related processes and collisional tectonics and sutured together by dismembered-ophiolite belts and major shear zones. The geology of the area comprises high-grade gneisses, volcanosedimentaiy sequences metamorphosed in the greenschist facies, all intruded by syn and syn-to-late orogenic calc-alkaline intrusives and post-orogenic alkaline bimodal gabbro-granite complexes. The coastal plain is geologically characterized by Cenozoic siliciclastic and shallow marine rift- related sedimentary sequences. Pliocene-Pleistocene is ‘represented by the thick older gravel unit al1d the emergent linear reef terraces. Several digital image processing techniques have been implemented to enhance the Landsat7 ETM+ digital satellite data. A Digital mosaic that covers almost all the Sudanese Red Sea Hills has been created using nine Landsat7 scenes. A 3x3 high-pass ﬁltered color composite image with a central coefficient of 16 proves to create the most optimized images that appear relatively brighter and more saturated. Four color composite triplets of band ratio images; B3/B5, B3/Bl, B5/B7; B5/B7, B5/B4, B3/B1; B5/B7, B5/Bl, (B3/B4)(B5/B4) and B5/B7, B3/Bl, B4/B3, have been composed to assist geological mapping. Directed band ratioing of the ratio color composite (B5/B7, B5/B4, B3/Bl) resulted in a well enhanced image that is characterized by satisfying saturated colors, strong retention of topographic expression and well pronounced lithological discrimination. Unstandardized and standardized principal component analyses have been done using the six reﬂected bands as well as a four selected bands. Some of their resulted images show relatively clear Landcover differentiation. Detailed lineaments ‘investigation has been done using high-pass ﬁltered, directional-ﬁltered images as well as the DEM. The lineaments of the study area show a clear bimodal pattern where a dominant N-S (360° :t: 10°) and subdominant E-W (9O° 1 10°) trend. The N-S lineaments are attributed to the shear fracture system that resulted from Heya-Gebeit terrain collisional episode and the NW-SE compressional forces that prevailed during the Neoproterozoic time. The E-W trending lineaments have been interpreted to result from the locally deﬂected, landward extension and propagation of the Red Sea rift-related transform faults. Dykes and dyke swarms present in the study area display a prominent unimodal pattern with a prominent E-W direction. These dykes were probably emplaced during a compressive condition with a minimum principal compressive stress that trends 356°-360°. This direction corresponds to the main direction of the N-S trending Pan-African sinistral master faults related to Onib-Sol Hamid and Baraka major shear zones. Shuttle Radar Topography Mission (SRTM) data of 90m resolution that covers the study area have been well utilized. Contour maps, shaded relief images as well as 3D scenes have been deduced from the SRTM data. The 3D scenes enhanced the visualization of the different geospatial data stored in the constructed geodatabase. A GIS-based geodatabase (Ge0RSH) has been designed for the study area. It is structured to include all the available spatial data that have been stored in four group layers namely; the Infrastructure, Topography, Geology and Processed Satellite data group layers. GIS cartography has been implemented to assist the ﬁnal design of the two geological maps of scale l:250,000. The ﬁnal layout of the two maps has been prepared in _a GIS framework.
Assessment and Evaluation of Groundwater Resources in Abu Habil Watershed North Kordofan State— Western Sudan
(Neelain University, 2006) MOHAMED ALI HASSAN DAHAB
Structural Control, Metamorphic Evolution and Genesis of the Gold Mineralization of Abu Khalag area, Central Bayuda Desert, River Nile State, Sudan.
(Al-Neelain University, 2006-08) Mohammed Al Nagashi
The study area constitutes part of east central Bayuda Desert; it lies about 400 Km North of Khartoum. It is composed of gneisses, schists, quartzites, calcsilicate rocks, marbles and amphibolites, which are metamorphosed under greenschist facies of regional metamorphism. These rocks were subjected to folding, shearing and fracturing accompanying metamorphism. The results of Abu Khalag rocks geochemical data show tholeiitic trends of high- grade amphibolites which indicate oceanic environment. The low-grade metavolcanosedimentary rocks show a calc-alkaline afﬁnity, which suggests an island arc paleotectonic environment. The syn-tectonic intrusions have calc-alkaline afﬁnity indicating a subduction related emplacement setting. The low-grade metasediments show a shelf environment of deposition. i Syn to late-granitoid intrusions were emplaced in weak planes of the above- mentioned units and have local thermal and metasomatic aureoles. Field observations have indicated that most of Au mineralized quartz veins in the study area are structurally and lithologically controlled. The auriferous quartz veins can be sub-divided into two phases, occupying fault planes, schistosity, bedding and traces of axial fold planes in permeable and reactive amphibolites and calcsilicate host rocks. The structural, mineralogical and geochemical characteristics together with the style of wall rock alteration of the investigated auriferous quartz veins suggest that they belong to the mesothermal type of gold mineralization. The study involves collecting samples of quartz veins and stream sediments. The background and threshold values are proposed for quartz veins as 0.2 ppm and 0.57 ppm respectively, and for stream sediments as 0.041 ppm, 0.3 ppm respectively. This study indicates that the trace elements Cu, Pb and Zn have greatest potential as indicator of gold mineralization and pathfinders.
Digital Image Processing of Landsat7 data and GIS Application for Geological Investigation in Jebel Erba Area, _ Red Sea Hills, NE Sudan _
(Al Neelain University, 2006-09) Ibrahim Ahmed Ali Babikir
Digital image ‘processing and Geographic Information System techniques, together with a limited reconnaissance ground truthing, have been used to investigate the geology of the area around J. Erba and J. Oda of the Sudanese‘ Red Sea Hills (RSH). The methodology fulﬁlled and the procedures followed during this study enabled the establishment of geodatabase named GeoRSl-I and the production of two geological maps of scale l:250,000. The area of study occupies the central part of RSH of Sudan that belongs to the Nubian Sector of the Arabian-Nubian Shield (ANS). It forms part of the Gebeit terrain that is known to be created among the other four terrains of NE Sudan (Tokar, Heya, Gabgaba and Geri) during the Pan-African event (950-50OMa) due to subduction-related processes and collisional tectonics and sutured together byidismembered-ophiolite belts and major shear zones. The geology of the area comprises high-grade gneisses, volcanosedimentary sequences metamorphosed in the greenschist facies, all intruded by syn and syn-to-late orogenic calc-alkaline intrusives and post-orogenic alkaline bimodal gabbro-granite complexes. The coastal plain is geologically characterized by Cenozoic siliciclastic and shallow marine rift- related sedimentary sequences. Pliocene-Pleistocene is represented by the thick older gravel unit and the emergent linear reef terraces. I - - i Several digital image processing techniques have been implemented to enhance the Landsat7 ETM+ digital satellite data. A Digital mosaic that covers almost all the Sudanese Red Sea Hills has been created using nine Landsat7 scenes. A 3x3 high-pass ﬁltered color composite image with a central coefﬁcient of 16 proves to create the most optimized images that appear relatively brighter and more saturated. Four color composite triplets of band ratio images; B3/B5, B3/B1, B5/B7; B5/B7, B5/B4, B3/Bl; B5/B7, B5/B1, (B3/B4)(B5/B4) and B5/B7, B3/Bl, B4/B3, have been composed to assist geological mapping. Directed band ratioing of the ratio color composite (B5/B7, B5/B4, B3/Bl) resulted in a well enhanced image that is characterized by satisfying saturated colors,‘ strong retention of ‘topographic expression and well pronounced lithological discrimination. Unstandardized and standardized principal component analyses have been done using the six reﬂected bands as well as a four selected bands. Some of their resulted images show relatively clear Landcover differentiation. Detailed lineaments investigation has been done using high-pass ﬁltered, directional-ﬁltered images as well aslthne DEM. The lineaments ofithe study area show a clear bimodal pattern where a dominant N-S (360° i 10°) and subdominant E-W (90° i 10°) trend. The N-S lineaments are attributed to the shear fracture system that resulted from Heya-Gebeit terrain collisional episode and the NW-SE compressional forces that prevailed during the Neoproterozoic time. The E-W trending lineaments have been interpreted to result from the locally deﬂected, landward extension and propagation of the Red Sea rift-related transform faults. Dykes and dyke swarms present in the study area display a prominent unimodalpattern with a prominent E-W direction. These dykes were probably emplaced during a compressive condition with a minimum principal compressive stress that trends 350°-360°. This direction corresponds to the main direction of the N-S trending Pan‘-African sinistral master faults related to Onib-Sol Hamid and Baraka major shear zones. Shuttle Radar Topography Mission (SRTM) data of 90m resolution that covers the study area have been Well utilized. Contour maps, shaded relief images as well as 3D scenes have been deduced from the SRTM data. The 3D scenes enhanced the visualization of the different geospatial data stored in the constructed geodatabase. A GIS-based geodatabase (GeoRSH) has been designed for the study area. It is structured to include all the available spatial data that have been stored in four group layers namely; the Infrastructure, Topography, Geology and Processed Satellite data group layers. GIS cartography has been implemented" to assist the ﬁnal design of the two geological maps of scale l:250,000. The ﬁnal layout of the two maps has been prepared in a GIS framework.
REMOTE SENSING AND GIS APPLICATIONS IN GEOLOGICAL MAPPING, PROSPECTING FOR MINERAL DEPOSITS AND GROUNDWATER-BERBER SHEET AREA, NORTHERN SUDAN
(Al Neelain University, 2006-09) SAMI OMER HAG EL KHIDIR
The geology of the East Bayuda Desert —Abiydia (Berber Sheet, NE-36-G) area in the north Sudan, has been investigated by means of remote sensing and Geo-Information System (GIS) techniques and limited geotraverses. Digital image processing of Landsat ETM+7 data and geo-spatial analysis were conducted to evaluate the use of remotely sensed data in geological mapping, mineral prospecting and hydrogeological investigation in such arid terranes. The study area represents a part of Bayuda terrane, and comprises Basement Complex rocks of Neoproterozoic age. The lithologies include the high-grade gneisses and migmatites, dismembered ophiolitic basic-ultrabasic rocks, metavolcanosedimentary sequence and supracrustal metasediments. These units have been intruded by syn- to late- and post-orogenic intrusions during and aﬂer the Pan-African orogeny. Phanerozoic sedimentary Formations cover the Basement Complex rocks, which in turn have been covered by Cainozoic basaltic volcanics. Most of these units have been covered in parts by Quatemary Nile silts, alluvial deposits and / or aeolian sand sheets. The East African Orogen has been manifested in the study area. The collision between the west and east Gondwanaland continents resulted in at least ﬁve deformational phases, which can be traced in Satellite image. The three ductile and two brittle deformational phases result from the collision of the Bayuda terrane with Halfa and Gabgaba terranes. The ﬁrst discemible deformational phase displayed by the isoclinal folds with E-W fold axis. These folds were refolded by close folds in NE-SW fold-axis fold. A third phase of open folds refolded the earlier fold with E-W fold axis. The ductile deformation has been followed by brittle deformational phase. The NE-SW trend Nakasib shear affected earlier structures, which in tum has been superimposed by N-S trend Keraf shear zone. Digital image processing was conducted to enhance the visual interpretation of the Landsat ETM+7 data. The IHS (Intensity-Hue —Saturation) transformation of the decorrelated stretched bands yielded an overall good lithologic discrimination. The two colour composite images 7, 4, l and 7, 5, 4 have been decorrelated stretched and then IHS transformed with the panchromatic band. The two colour composite images display well saturated hues and morphological signatures, which make them the best in discriminating various lithological units. The Principal Component transformations yield saturated images and resulted in a higher signal-to — noise ratio when standardized coefﬁcients were used instead of the covariance matrices. Band ratioing images yielded geologically informative images, where both spectral and morphological information are preserved. Selective merged images were used by combined in the red-green-blue colour gun different and theless correlated images from various techniques. Colour composite images Litho-l, Litho-2 and drainage-image have been built. The Litho-1 colour composite image utilizes the PC2 (of the six bands) in red, band ratio 5/7 in green and DC2 (of bands 5, 4 & 3) in blue. The Litho-2 colour composite image utilizes PC2 (of the six bands) in red, DC2 (of bands 5, 4 & 3) in green and band ratio 3/1 *5/7 in blue. The drainage colour composite image utilizes band ratio 5/7, DC2 (of bands 5, 4 & 3), PC5 (of the six bands) in red, green and blue, respectively. These saturated and morphological expressed images display well discrimination ability of diverse lithological unit and structural elements. On the hand the drainage image created by selecting the band ratio 5/7, DC2 (of bands 5, 4 & 3) and PC5 (of the six bands) in the R, G and B, respectively. It was found that this image is superior in delineation the alluvial in the wadies, thus it was used mainly in mapping them. Geological map of Berber Sheet (scale of l:250000) has been produced utilizing the Geo- Berber database. The Geo-Berber includes the digitally processed remotely sensed data, ﬁeld work and structural and petrographical data. These data combined with demographic data. The SRTM data provide the base for the elevation data in the geo-database. The extracted DEM render the 3D terrane visual image that assists the lithological discrimination by its morphological expression. The geo-spatially analysed lineaments data used in the Geo-Berber database have been produced by the spatial and structural analyses of the edge enha.nced- ﬁltered Landsat images. Prospecting for mineral deposits has been exploited using the spectral criteria of the gossans and rock alteration associated with mineralization. The geo-spatially analysed- supervised classiﬁed colour composite images of Crosta (Feature Oriented Principal Components image) and Sabin’s ratio image proved to support the demarcation of the mineralization. The results are found to be controlled with the level of erosion as witnessed in the deeply eroded terranes as in the East Bayuda Desert and Abidiya areas. In the mineralized Ariab-NW Nakasib area that is characterized by low-level of erosion, the technique revealed optimum results in depicting the gossans. This malfunction in the remote sensing-GIS mineral prospecting model can be overcome by combining other geological and structural information in the geo-spatial analysis. A remote sensing-GIS model for depicting fractures and structurally-controlled aquifers in crystalline rocks prove to guide the prospecting of groundwater in Basement Complex terrane of the East Bayuda Desert. Digital image processing, lineament analysis and geo- spatial analysis combined with ground geophysical investigation gave best possible results as documented by the drilling activities.