Vertical Derivative Research Articles

Imaging magmatic intrusions using derivatives of high-resolution aeromagnetic data over the Nigerian sector of the chad Basin

Magmatic activities can either positively or negatively affect hydrocarbon generation in sedimentary basins. The effect of these activities can be positive when they prevent further migration and escape or negative when extreme pressure and high temperature force the hydrocarbon to evaporate at the time of emplacement. The aim of the study is to confirm the presence of intrusive structures in the Nigerian sector of the Chad Basin using derivatives of aeromagnetic data. The enhanced body and edges suggest a dyke-like structure intruding the Chad Basin. The edges are identified as areas that are skewed on the first vertical derivative and maxima over the analytic signal generated by the dyke-like intrusion. Three profiles with lengths ranging from 68.4 km to 263.9 km were generated on the derivatives of aeromagnetic data, and the analytical results indicate dyke-like structures of 0.3 km to 0.4 km in size.

Aeromagnetic investigation of crustal stability of Osi, north central Nigeri

High-resolution aeromagnetic data of Osi north central Nigeria has been processed with a view to establish the earthquake-prone fault zones in the area. The analytical signal amplitude, shaded relief total horizontal derivative, first vertical derivative and 3D Euler deconvolution maps produced from the residual magnetic intensity anomalies of the study area identified the structural features in the area. The locations and the orientations of the extracted magnetic lineaments were revealed by the structural map of the area and the associated rose diagram. The lineaments were observed to strike NE-SW, ENE-WSW, E-W, NW-SE, WNW-ESE, NNE-SSW and NNW-SSE. The upward continuation maps showed evidence of deep-lying faults while the source parameter imaging and spectral analysis revealed depth to magnetic sources ranging from 81 m to 402 m and 103 m to 460 m respectively. The predominant NE-SW and NNE-SSW trending faults in the study area depicted stress history related to Ifewara faults; which is an indication of possible impending earthquake occurrence in the area.

Geophysical investigation of crustal structural framework of Ilesha, southwestern Nigeria

The interpretation of the aeromagnetic dataset of Ilesha southwestern Nigeria has been carried out to reveal possible future earthquake hazard as well as establish the groundwater potential of the area. The edge detection methods involving the analytical signal amplitude, the total horizontal derivative, the first vertical derivative and the 3D Euler deconvolution were performed on the residual magnetic intensity anomalies to identify the linear structural discontinuities associated with lithological boundaries/ faults in the area. The upward continuation filter and depth estimation procedures of source parameter imaging and radially averaged power spectrum were applied to the residual magnetic intensity data to map geological structures such as faults as well as determine the depth to crystalline basement rocks in the area. The obtained lineaments observed to trend predominantly towards the NE-SW direction indicative of Pan African Orogeny, suggest possible high yield groundwater aquifer zones. The upward continuation filtered maps showed evidence of deep-lying faults to depth beyond 2 km. The 3D Euler deconvolution plots and spectral analysis revealed depth to magnetic sources ranging from 55 m to 345 m and 13 m to 250 m, respectively. The delineated structural discontinuities in the study area revealed stress history similar to Ifewara-Zungeru fault network, suggestive of possible future earthquake occurrence in the area. It is however recommended that further geophysical studies should involve electrical method to establish the groundwater potential as well as the stability of the basement underlying the area.

Aeromagnetic Mapping and Radioelement Influence on Mineralogical Composition of Mesothermal Gold Deposit in Part of Ilesha Schist Belt, Southwestern Nigeria

ABSTRACT Airborne magnetic and radiometry data sets over potential gold mineralisation associated with mesothermal alteration zones in the western Ilesha schist belt, Southwestern Nigeria, were interpreted. This was done to provide information on possible extent of geologic transformations that accompanied gold mineralisation in the area. Interpreted gamma spectrometric data were successfully used in delineating zones of hydrothermal alteration associated with potassium K enrichment as the target for gold deposits. The geological structural features that host the ore deposits were identified as lineament represented by lithological contacts and faults/fractures that were successfully exacted from the airborne magnetic data. The potassium deviation (KD) map was computed to enhance the potassium signature of rocks in the area of study. Thus, the KD map represents real potassium distribution across the study area emanated from hydrothermal alteration where hydrothermalised zones were displayed by high KD values. First vertical derivative (FVD) and total horizontal gradient (THG) maps were used to delineate lineaments. These lineaments were connected using the frequency rose diagram with two main lineament set,; major and minor lineaments observed. The 3D Euler deconvolution (EUD) method was also applied on the THG map to locate and evaluate depths to subsurface structures. The best 3D EUD solution for dykes and contacts modelled using the Structural Index of zero (S.I = 0) was used to estimate the depth to these anomaly sources at 300 to 700 m in the study area. The EUD results also revealed several subsurface structures which were hidden in the existing geological map of the study area. A prospective mineralisation map was produced from the synthesis of both magnetic lineaments and alteration zones maps derived for the study area, showing the areas of probable high mineral resources. Strong relationships were observed between the mapped hydrothermal altered zoneseologic structures and superimpose known gold mining pits.

Reformulating scalar–tensor field theories as scalar–scalar field theories using a novel geometry

In this paper, I shall show how the notions of Finsler geometry can be used to construct a similar geometry using a scalar field, f, on the cotangent bundle of a differentiable manifold M. This will enable me to use the second vertical derivatives of f, along with the differential of a scalar field φ on M, to construct a Lorentzian metric on M that depends upon φ. I refer to a field theory based upon a manifold with such a Lorentzian structure as a scalar-scalar field theory. We shall study such a theory when f is chosen so that the resultant metric on M has the form of a Friedmann-Lemaître-Robertson-Walker metric, and the Lagrangian has a particularly simple form. It will be shown that the scalar-scalar theory determined by the Lagrangian can generate self-inflating universes, which can be pieced together to form multiverses with non-Hausdorff topologies, in which the global time function multifurcates at t = 0. Some of the universes in these multiverses begin explosively, and then settle down to a period of much quieter accelerated expansion, which can be followed by a collapse to its original, pre-expansion state. This article is part of the theme issue 'The future of mathematical cosmology, Volume 1'.

Mineral exploration of Iwo-Apomu Southwestern Nigeria using aeromagnetic and remote sensing

The tectonic framework, lithostructural and mineralised zones of Iwo-Apomu region of Precambrian Basement Complex rocks were investigated using integrated aeromagnetic and satellite remote datasets. Fast Fourier Transforms (FFT) performed on aeromagnetic data were: Butterworth Filter (BF), Reduction to Magnetic Equator (RTE), Regional field, Residual field, Tilt-Angle Derivative (TDR), First and Second Vertical Derivative (FVD and SVD), Tilt angle and Total horizontal derivative (TDR and TDHR), and Total Gradient Amplitude (TGA); which range from −31.97 – 123.24, −27.12 – 131.75, 1.52 – 117.90, −58.55 – 50.42, −1.35 – 1.36, −0.0712 – 0.0643, 0.0004 – 0.0102, 0.005 – 0.261 respectively. Continuations and Radially Average Power Spectrum; revealed the variations of the deep-seated basement rocks, the structures and the mineralised anomalous bodies with depth. The upward continuation maps also show that the regional trends of the mapped lithologies and lineaments/faults in the area are generally in NW-SE, E-W, and NW-SE directions. These filters defined the lithostructures, lithological boundaries, geological structures, contacts, faults, folds and mineral deposit. The results of satellite data on Principal Component Analysis (PCA), False Colour Composite (FCC) images and Band Ratio (BR) discriminated the different rock types, lithostructural boundaries and alteration zones that hosted the mineralized ore bodies which trend in NE–SW and minor NW–SE and E–W directions. The combined techniques generated showing the probable positions and trend of suspected fault/fracture, mineral deposit as well as other basement structures.

Imaging crustal features and Moho depths through enhancements and inversion of gravity data from the Philippine island arc system

The Philippine archipelago is a complex island arc system, where many regions still lack geopotential field studies. The high-resolution isostatic anomaly and free-air anomaly digital grids from the World Gravity Map (WGM) were processed and analyzed to present a general discussion of the Philippines’ gravity signatures and contribute to understanding its regional geology and tectonics. The isostatic anomaly map was continued upward to investigate the high-density ophiolitic basement rocks and low-gravity sedimentary basins at depth. The first vertical derivative (1VD) filter was applied to the free-air anomaly grid map to locate regional structures represented by density contrast boundaries. The depth to the top of the Moho and basement rock over the Sulu Sea was computed using the two-dimensional (2-D) radially averaged power spectrum analysis. Three-dimensional (3-D) gravity inversion was applied to some major sedimentary basins in the Philippines to present 3-D subsurface density contrast models. The interpreted gravity maps highlighted prominent geologic features (e.g., trench manifestation, ophiolite distribution, basin thickness). The negative isostatic anomalies (< 0 mGal) represent the thick sedimentary basins, while the moderate signatures (0 to 80 mGal) correspond to the metamorphic belts. The distinct very high-gravity anomalies (> 80 mGal) typify the ophiolitic basement rocks. The gravity data’s upward continuation revealed contrasting deep gravity signatures; the central Philippines with continental affinity (with 20–35 mGal) was distinguished from the regions with oceanic affinity (with 45–200 mGal). The 1VD map over the Sulu Sea showed anomalies associated with shallow features dominantly related to the Cagayan Ridge. The 2-D radially averaged power spectrum analysis exposed gravity anomalies with tectonic significance (e.g., basement characterization, Moho depth estimation). The estimated average Moho depth in the Sulu Sea is from 12 to 22 km, while the average basement depth is within the range of 5 to 11 km. Lastly, the 3-D subsurface density contrast models characterized the very low-density zones representing the deep (> 7 km) sedimentary basins in the northern Cagayan Valley and southern Central Luzon basins. Furthermore, thin (~ 3.5 km) sedimentary formations are inferred for the low-density areas in northern Agusan-Davao and eastern Cotabato basins.

A [formula omitted]-functional Itô’s formula and its applications in mathematical finance

Using Dupire’s notion of vertical derivative, we provide a functional (path-dependent) extension of the Itô’s formula of Gozzi and Russo (2006) that applies to C0,1-functions of continuous weak Dirichlet processes. It is motivated and illustrated by its applications to the hedging or superhedging problems of path-dependent options in mathematical finance, in particular in the case of model uncertainty. In this context, we also prove a new regularity result for the vertical derivative of candidate solutions to a class of path-depend PDEs, using an approximation argument which seems to be original and of own interest.

Structure Boundary Separating using Gravity Data for Central and Southern Parts of the East Java Basin Beneath the Quaternary Volcanic Deposits

Stratigraphic interpretation shows that the relationship between Cenozoic volcanic rocks deposited in the Southern Mountains and marine clastic volcanic rocks in the Kendeng Basin possibly forms a stratigraphic transition bordered by the major fault that is yet to be defined. The thick Quaternary volcanic deposits obstruct field observation on the surface. Miocene outcrops in limited presence are found on the volcanic slope, positioned relatively more to the north than the same outcrop. This feature indicates major thrusting in southern Java that moved it to the north. The gravity data analysis was used to obtain the field observation and identify the subsurface geology. Total Horizontal Derivative analysis of the gravity data showed a major fault boundary with a relative west-east direction separating the high Bouguer anomaly area in the south from a large negative area of about -50 mGal in the north. Second Vertical Derivative analysis reconstructed the fault slope direction and showed a south-facing slope with a large angle. Based on the combination of the surface data and the subsurface analysis, the boundary is a major fault with a west-east direction on the south side of the Quaternary volcanic range and a south-facing slope. It is interpreted as the result of the compressive tectonics that formed the fold-thrust belt system.

Geophysical Studies to Identify Iron Mineralization Anomalies Using Terrestrial Magnetometry in The ChakChak Area

Mineral exploration is the underlying theme of industry and discoveries because humans have been exploring for minerals from the very beginning, based on their needs. This research aims to find promising areas of iron ore mineralization in Chak-Chak Exploration area of Yazd province, Iran. The study’s range lies at a latitude of 32-33 degrees north and a longitude of 54-55 degrees east. This study collected data using terrestrial magnetometry at 6222 points in a 20 m x 10 m grid. Initially, these data were pre-processed, such as removing the magnetic field effect of the Earth's core. Subsequently, processes such as applying polarisation filters, trend surface correction, upward and downward conversions, vertical derivatives and analytical signals on the terrestrial magnetic data were performed. The Exploration range contains numerous peaks in the southwest and other summits in the northeast, according to the research findings. These anomalies are consistent with igneous rock units (rhyolites) and faults. Consequently, it may be stated that one of the most rapid and least costly methods of detecting iron anomalies is terrestrial magnetism, which produces satisfactory results.

Interpretation of Airborne Gravity Data over Kushaka Schist Belt, Northwestern Nigeria

The Kushaka Schist Belt has a peculiar importance due to its minerological potential. The area is located on the Latitudes 10°30’-110 and Longitude 6°30’-7° in the northwestern part of Nigeria. Kushaka airborne dataset (Sheet 222) obtained from Nigerian Geological Survey Aagency was interpreted to delineate litho- structural architectures that could favour the exploitation of potential economic minerals over the area. The analyzed results of the bouguer map of Kushaka show the distribution of the gravity anomalies and magnitudes of the concealed shear and weak zones being characterized by low to very high gravity anomalies. The upward continued bouger anomaly map at distance of 3000m reveal the regional trends so as to generate a subsequent residual field where several filtering operations were carried out. Several enhancement techniques were carried out on the airborne gravity data to reveal the locations, edges/boundaries, trends, and depths of gravity anomalies. The analytic signal gravity and its superimposed maps reveal areas with low to high amplitude signals. Low amplitude regions are suggested to be dominated by highly fractured schistose, quartzitic rocks and fractures. On the other hand, high amplitude regions are likely occupied by denser biotite granitic and gneissic rocks. Also, the First Vertical Derivative gravity anomaly map shows low gravity region which indicate the presence of fracture. The horizontal gravity gradient map shows high, positive gravity regions which may be attributed to the presence of a regional structure trend in the area. Low gradient anomalies can also denote presence of graben-like structures or other geological depressions. The depth analysis over Kushaka schist Belt suggests depth to top for shallow bodies ranging from 385m to 560 m with an average depth of 440.55 m while the deep sources have depths ranging from 1910m to 2480m with an average depth of 2111.1m. The obtained Euler anomalies depths ranged from &lt;2607m to &gt;5858m suggesting that mineralization around the study area is structurally controlled, an evidence of hydrothermal alteration zones. The structural solution (S.I=0) result displays two NW-SE trending short linear features, an indication of tectonic metamorphic phases of Pan-African orogeny that harbor mineralization. The results therefore, suggested intensed deformation of the basement rocks with tectonic framework suitable for mineralization.

Application of geophysical method to delineate Kaolin deposit at Kankara, Northwestern Nigeria

Area around Kankara Local Government Area of Katsina State, which lies within the Northern Nigerian Basement complex, is considered as one of the most prospective regions for Kaolin mineralization in Nigeria. A geophysical survey involving aeromagnetic and electrical resistivity survey was employed to delineate the fault and features that may be related to the mineralization. The aeromagnetic map results which included the first and second vertical derivatives and analytical signal map, revealed that a continuous linear feature trends Northwest to Southeast direction and Northeast to Southwest direction with a few traces along East-West and North-South. The electrical resistivity tomography was taken at a mining site along which the fault line passes through. It revealed that the Kaolin mineral lies within the overburden and weathered layer, with depth approximately 10-15m, extending from East -West.

Comparative analysis of AVIRIS-NG and Landsat-8 OLI data for lithological mapping in parts of Sittampundi layered complex, Tamil Nadu, India

The present study addresses a comparative analysis of the potentials of Airborne Visible and infrared imaging spectrometer -next generation (AVIRIS-NG) data, with respect to Landsat-8 Operational Land Imager (OLI) data for mapping of sporadic exposures of mafic cumulates within the anorthosite intrusion and delineation of major lithological units of Sittampundi layered complex. AVIRIS-NG and Landsat-8 OLI data were initially compared using scene-based relative signal-to-noise ratio (SNR) analysis. Subsequently, spectral anomaly maps were generated to map different lithological rock units using the constrained energy minimization (CEM) approach. Spectral maps derived using CEM were further filtered by low-pass filtering to control the false-positive result. Spectral angle mapper (SAM) classification technique was applied to analyze the suitability of AVIRIS-NG and Landsat-8 OLI data for lithological mapping. Confusion matrix analysis was carried out to assess the SAM classified maps. The first vertical derivative (FVD) map of magnetic anomaly and field evidence/geological exposures were used to validate the results. SNR analysis indicates the superior signal strength of AVIRIS-NG data than Landsat-8 OLI data. Moreover, combined analysis based on CEM and SAM of remote sensing data and FVD of magnetic anomaly reveals that the false-positive area indicating metagabbro/mafic cumulate is lower in AVIRIS-NG data than Landsat-8 OLI data. This is because of the relatively poor SNR, spectral and spatial resolutions of Landsat-8 OLI data; however, it can be good enough for mapping of metagabbro/mafic cumulate when AVIRIS-NG data is unavailable.

Global well-posedness of z-weak solutions to the primitive equations without vertical diffusivity

In this paper, we consider the initial boundary value problem in a cylindrical domain to the three-dimensional primitive equations with full eddy viscosity in momentum equations but with only horizontal eddy diffusivity in the temperature equation. Global well-posedness of a z-weak solution is established for any such initial datum such that itself and its vertical derivative belong to L2. This not only extends the results in the work of Cao, Li, and Titi [Physica D 412, 132606 (2020)] from the spatially periodic case to general cylindrical domains but also weakens regularity assumptions on the initial data, which are required to be H2 there.

ASSESMENT FOR GOLD MINERALISATION POTENTIAL OVER ANKA SCHIST BELTS NW NIGERIA, USING AEROMAGNETIC DATA

High resolution aeromagnetic data combined with the geological settings of the study area were employed in delineating the structures that may host the gold mineral within the middle parts of Anka schist belts. These data were analysed, processed and interpreted using; reduction to magnetic equator (RTE), first and second vertical derivatives (FVD &amp; SVD), geologic contact, analytic signal (AS), centre for exploration targeting (CET) and source parameter imaging (SPI) techniques. RTE technique was applied to prevent North-South signal in the data from dominating the results, due to the area falls under the low latitude. FVD and SVD maps shows major NE trend of the structures within study area. CET map revealed the regions with linear structures (lineament) which were trending South-Eastern regions of the study area. Geologic contact map has highlighted high density of structural contacts combined with junctions and intersections of different structures found within the area. AS map enhanced the variation in the magnetisation of the magnetic sources and also indicates the boundaries of anomaly texture. These techniques have revealed the regions that may host gold mineralisation potential areas to be; northern parts of Bukkuyum, Anka, Maru, Sakaba, Mariga, southern part of Wasagu/Danko. Most of the structures (lineaments) found within areas were associated with the vein of the mineralisation potential which plays important role in determine a gold mineral. Results from these techniques also correlated

Structural Analysis of High Resolution Aeromagnetic Data. A Case Study of Akko and Environs, Gongola Basin upper Benue Trough Northeastern Nigeria: Implication for Mineralization and Groundwater Potentials

Magnetic method had proved very effective in the area of subsurface anomaly studies and structural delineation worldwide. Sheet number 151(Akko sheet) of the high resolution digital airborne magnetic data was obtained from the Nigerian Geological Survey Agency (NGSA). Analysis of the data was done using first horizontal and first vertical filters while the residual field was obtained using the polynomial fitting method. Lineaments of the study area were generated from SRTM (shuttle radar thematic mapper) and DEM (digital elevation model) by producing four shaded relief images at solar altitude of 45˚, 50˚, 60˚ and 90˚. The first horizontal and first vertical derivative filters exhibited magnetic trend consistent with the lineament trend of the study area, which showed major trends in NE-SW and NNW-SSE direction and minor trends along NW-SE.

Aeromagnetic-Imaged Basement Fault Structure of the Eastern Tarim Basin and Its Tectonic Implication

The property of the magnetic basement and the faults in the basement is significant for structural evolution, the Phanerozoic deposition, and oil resource exploration of the Tarim Basin. Based on the newly acquired aeromagnetic and industry seismic data, we mapped the distribution of basement faults by applying magnetic gradient-processing methods such as the horizontal gradient derivative, the first vertical derivative, the tilt derivative, and the upward continuation method. The dips of basement faults were confirmed and the susceptibilities of basement blocks were obtained by forward modeling of five profiles using the constraint of sedimentary strata depth and Moho topography. On the basis of comprehensive analysis of the magnetic anomalies, the distribution and inclination of basement faults, and susceptibilities differentiation obtained by forward modeling and field measurement, the property of the basement faults and their implication were discussed and interpreted. Our results show that the origin of the Central Highly Magnetic Anomaly Belt is highly magnetic Archean metamorphic rocks. The weakly magnetic Southeastern Domain and highly magnetic Central Tadong Domain assembled along the Tadong South Fault during the Paleoproterozoic. The Paleozoic Cherchen Fault is just an interior fault in the weakly magnetic Southeastern Domain although it presents a large vertical fault displacement. Considering the prominent variation of strikes of the Tadong North Fault system, and the moderately magnetic anomalies in the Northeastern Mangal Domain corresponding to the center of Neoproterozoic deposition, it is likely that the basement of the Northeastern Mangal Domain modified by the Neoproterozoic rifting could be originally the same as the basement of Central Highly Magnetic Anomaly Belt.

Interpretation of the subsurface tectonic setting of the Natrun Basin, north Western Desert, Egypt using Satellite Bouguer gravity and magnetic data

The Natrun Basin, north Western Desert of Egypt, represents a significant oil and gas province as it contains numerous oil and gas production fields. The basin has huge hydrocarbons recovery, mainly from the Jurassic rocks and minor amounts from Cretaceous rocks. The satellite Bouguer gravity, magnetic data, geologic, and available deep-drilled wells represent the primary data for the current research. The study's main goals are to interpret the subsurface tectonic setting, investigate the tectonic evolution of the Natrun Basin, and estimate the depth to the basement surface. Several geophysical techniques were applied to the satellite Bouguer gravity and magnetic data using Geosoft Oasis Montaj (Version. 8.3.3, 2015) to achieve the study's goals. The total magnetic intensity data was transformed into the reduced to pole map to prepare the magnetic data for further separations. The power spectrum was applied to detect the cut-off wavenumbers used in high and low-pass filters to separate the regional and residual anomalies. The first vertical derivative was applied to enhance the residual anomalies. The total horizontal and tilt derivatives were calculated to delineate the edges of the subsurface causative bodies. The 2D modeling was applied to estimate the depth to the basement surface and reveal the configuration of the subsurface rock units. A basement structure map was constructed to reveal the subsurface tectonic setting and evaluation of the Natrun Basin. The depth to the basement surface ranges between 1880 m and 6200 m. The subsurface tectonic setting of the basin was controlled by the N–S East Africa, NE-SW Hercynian, E-W Mediterranean, ENE-WSW Syrian Arc, NW-SE Gulf of Suez, and NNE-SSW Aqaba tectonics from the oldest to the youngest, respectively.

Geological preconstruction assessment of the proposed site for Layifa housing estate, Jigawa State, Nigeria from aeromagnetic data

Preliminary geological preconstruction assessment of a proposed housing estate site in Jigawa State, northern Nigeria has been done from analysis of aeromagnetic data for the purpose of optimised physical planning, particularly in the area of forestalling any potential risk that may be associated with the existence of linear geological structures or sub-surface conditions that may be inimical to engineering structures. The techniques adopted for the data enhancement include the total horizontal derivative, second vertical derivative and Euler deconvolution solutions. Spectral analysis was also performed on the data to determine depth to the magnetic basement rock, hence overburden thickness and basement topography. Data enhancement analyses delineated considerable number of semi-regional to regional-scaled lineaments, the existence of which presented the study area as a suspected shear zone. Basement topography was found to be highly rugged with evidence of rift-controlled subsidence detected in the eastern section. Having just a few lineaments traversing through it and being located where the basement topography is relatively less undulating, a trapezium-shaped area in the central southern region was identified as the most stable location within the study area, geologically. Two unmapped geologic bodies were delineated from the magnetic data as well. Drilling efforts confirmed an initially unmapped quartzite at the location where one of the two unmapped bodies were delineated and this validated the potency of magnetic data as an aid for geologic mapping. If established that lineaments F25, F26 and F28 traversing through this area are not seismically active, the trapezium-shaped area, said to be least affected by geological factors, could be used for building constructions. However, it is advised that high-rise buildings should not be concentrated in the area but cascaded buildings are recommended due to the fact that a portion of the area is located on a hill-slope and the topography of the basement rock underneath is also coincidentally sloppy. The study area was found to be a shear zone with highly undulating basement topography. Therefore, construction on the site must be approached with caution.

Nickel Deposit Depth Estimation Using Source Parameter Imaging and Euler Deconvolution of Aeromagnetic Data of Bakin Kogi and its Environs in Jema’a Local Government Area of Kaduna state

This study aimed to estimate the depth of Nickel deposit in Bakin Kogi – Dangoma region, which lies between latitude 901''and 9027'N and longitude 8000' and 8017' E. The study area is located in Jema’a local government area of Kaduna state. The data was gridded using Oasis Montaj® to produce Total magnetic Intensity Map (TMI) of the area, and further subjected to some filtration processes in order to obtain regional and residual map of the study area. Enhancement methods such as first vertical derivative and analytic signal methods were applied to the residual map to delineate the area with potential Nickel deposit. The quantitativemethod applied were source Parameter Imaging and Euler Deconvolution to determine the various depths of Nickel deposit. From the results of the TMI map and the residual map, the magnetic intensity of the study area was between 32976.5 to 33093.3 nT and 32963.6 to 33072.9 nT respectively with Bakin kogi-Dangoma region, having the highest magnetic intensity of about 33093.3nT and 33072.9 nT respectively. The study area has a high magnetic intensity due to nickel deposit because Nickel ore environment are notable with recognizable “magnetic stratigraphy”, prospective mafic-ultramafic contact, typified by strong magnetic contrast. Abrupt changes in the magnetic intensity infer position of the outer contact of a Nickel bearing zone. The results on the superimposed analytic map on the lineament map showed regional lineaments in Bakin kogi-Dangoma region trending NE -SW, ENE – WSW and NNE – SSW directions. The fractures and faults seen around the study area were strongly associated with minerals deposit. The results of Source Parameter Imaging (SPI) gave a depth of shallower magnetic sources ranges from 92.7 to 116.0 m with an average depth value of 104.35 m while the depth of deeper magnetic sources ranges from 651.2 to 976.2 m with an average depth of 813.7 m. The results obtained from 3D Euler deconvolution which was associated with dykes (SI = 1) anomaly produced at a shallower depth range of 100 - 700 m. Results obtained, shows a correspondence between the depths results obtained from the SPI and that of the Euler Deconvolution methods, indicating correlation in the magnetic depth estimation.