IOSR-JAGG   Volume-5 ~ Issue-5 ~ SEP-OCT-2017

Abstract: The analysis of aeromagnetic data over Middle Benue Trough and its adjourning basement terrain using Source Parameter Imaging (SPI) in Oasis montaj version 8.2 indicates that, the depth to magnetic sources in adjourning basement varies between 0.2 km to1.7 km. The depth to magnetic source at the middle of the study area which made up of the Cretaceous sediments of middle Benue varies between 4 km to 6 km. The shallow depth at the adjourningbasement could be as a result of basic intrusive rocks of the basement terrain, while the deeper sources at the middle of the study area that made upof cretaceous sediments of middle Benue, could be due to rifting of the Benue Trough. From the results obtained the adjourning basement terrain could be a potential site for mineral exploration while, the sedimentary section belonging to the middle Benue Trough could be a potential site for petroleum exploration.

Keywords: Oasis Montaj, basement terrain, Source Parameter Imaging, Middle Benue and Magnetic source

Abstract: The mesoproterozoic Kibara belt in central Africa has the subdivision of the two mobile belts which are the Karagwe -Ankole belt (KAB) and the Kibara belt (KIB), separated by Rusizian terrane. The KAB, which spans Rwanda, Burundi, Southwestern Uganda and Northwestern Tanzania, and the KIB together host a large metallogenic province that is composed of numerous rare -metal ore deposits mineralised in niobium-tantalum(Nb-Ta), tin(Sn) and tungsten(W).The part of the Karagwe-Ankole Belt located in Rwanda contains the bulk of cassiterite, columbite-tantalite, and wolframite. These ore minerals have been termed 3Ts and occur in Nb-Ta-Sn pegmatites, W-Sn hydrothermal quartz vein deposits and Sn greisens, which are components of one composite metallogenic system related to the............

Keywords: Karagwe-Ankole belt, Kibara belt, Cassiterite, Columbite-Tantalite, Wolframite, Rwanda

Abstract: The Muglad rift basin of interior Sudan is an integral part of the West and Central African Rift System (WCARS). It has undergone a polyphase development which has resulted in three major phases of extension with intervening periods when uplift and erosion or non-deposition have taken place. The depositional environment is nonmarine ranging from fluvial to lacustrine. The basin has probably undergone periods of transtensional deformation indicated by the rhomb fault geometry. Changes in plate motions have been recorded in great detail by the stratigraphy and fault geometries within the basin and the contiguous basins. The rift basin has commercial reserve of petroleum, with both Cretaceous and Tertiary petroleum systems active. The major exploration risk is the lateral seal and locally the effect of the tectonic rejuvenation as well as tectonic inversion. In some oilfields, the volcanic rocks constitute a major challenge to seismic imaging and interpretation.

Abstract: F-x prediction filters are made use of in this exercise for random noise attenuation. These filters require definition of spatial filter length, spatial design window and primary (signal) model's temporal window for a cut off frequency. It is inferred using real earth data that attenuation of random noise is crucially dependent on the choice of primary model's temporal window in achieving better S/ N and continuity of the primary events.

Keywords: f-x prediction filter, gather, random noise, spectrum, stack

Abstract: We present in this paper a numerical study of the excitation of high and low frequency waves – electromagnetic and electrostatic – by the electron beams. This study is useful for fusion plasma physics as well as for auroral plasma physics. We have solved the fully kinetic plasma dispersion relation using the numerical code developed by A. F. Viñas at NASA/GSFC, and found the real frequency and the growth/damping rate for the problem relevant to the plasma modes. Those modes are the electromagnetic/electrostatic ion cyclotron wave (EMIC/EIC), the kinetic Alfvén wave (KAW), the fast magnetosonic wave (FMW), the ion and electron whistler (IW/EW) waves, lower/upper hybrid (LHW/UHW) waves...........

Keywords: Dielectric Tensor, Eigenfrequency, Cherenkov Damping, Kinetic Alfven Wave, Fast Magnetosonic Wave, Electromagnetic Ion Cyclotron Wave, Electrostatic Ion Cyclotron Wave, Whistler Wave, Lower Hybrid Wave, Upper Hybrid Wave

Abstract: The total-field aeromagnetic data over Birnin – Kebbi and its adjoining areas, bounded between longitudes 4.000E to 5.000E and latitudes 11.500N to 12.500N were obtained and analyzed for subsurface lineament and depth analyses using first vertical derivative and local wavenumber methods. Orientational analysis of the lineaments inferred from the first vertical derivative map suggests that the major subsurface structural trends in the area were oriented along ENE-WSW, NE-SW and E-W directions while minor trends were along NW-SE, NNE-SSW, NNW-SSE and N-S directions. Result obtained from the depth analysis, as shown by the depth- to- basement map, suggested sedimentary thickness between 0.77 km to 2.31 km with the deepest areas, around Giru, associated with sedimentary thickness between 2.0 km to 2.31 km. The estimated sedimentary thickness and the temperature regime around the deepest areas were interpreted to be sufficient enough to warrant further hydrocarbon investigations..

Keywords: Sokoto basin, lineaments, first vertical derivative, local wavenumber, sedimentary thickness

Abstract: Crystalline limestones, marbles, calc-gneisses, etc., are the metamorphosed equivalents of originally sedimentary carbonate rocks changed by contact and regional metamorphism. Depending upon the original composition, they may be calcitic, or dolomitic. Impurities may occur as various calc-silicates and other minerals. The present study deals with the petrographical study of the limestone and the associated rocks occurred in the study area. The limestones and the associated rocks were collected from the study area for thin section preparation and petrographical studies. Thin sections were prepared according to the standard procedures. The Euromax Holland petrographic microscope was used for thin section studies. The mineral assemblages were identified both in plane and crossed polarised light. The petrographical investigations reveal that the rock specimens are dominated by.................

Keywords: Calc-granulite, limestone, petrography, mineral assemblages