scholarly journals INTERPRETATION OF AEROMAGNETIC DATA AND LANDSAT IMAGERY OVER THE NIGERIAN YOUNGER GRANITES IN AND AROUND KAFANCHAN AREA, NORTH-CENTRAL NIGERIA

2021 ◽  
Vol 4 (4) ◽  
pp. 323-333
Author(s):  
S. Mustapha ◽  
S. Suleman ◽  
S. R. Iliyasu ◽  
E. E. Udensi ◽  
Y. A. Sanusi ◽  
...  
Keyword(s):  
Landsat Imagery ◽  
Magnetic Anomalies ◽  
Biotite Granite ◽  
Aeromagnetic Data ◽  
North Central ◽  
The North ◽  
Area North ◽  
First Vertical Derivative ◽  
Basic Igneous Rock ◽  
Western Half

In this research the lineaments of the Kafanchan area in North-central Nigeria were investigated in order to explore the mineralization zones of the area. Aeromagnetic data over Kafanchan and environs within the Younger Granite Province, in the North-Central Nigeria were collated and analyzed. The aeromagnetic map of the area was interpreted both qualitatively and quantitatively so as to identify the nature of the magnetic sources and the trends direction in the study area. The trend of the Total Magnetic Intensity (TMI) map is predominantly in NE-SW. The First Vertical Derivative (FVD) Lineaments Map was also correlated with LADSAT lineaments map and both maps agreed in most areas. The study area is characterized by predominant magnetic lineament trend in NE-SW direction and subordinate E-W direction. The result also shows that the most significant structural trends affecting the distribution of these magnetic anomalies in the study area is in NE-SW direction. The TMI map indicates that there are three major mineralization zones in the study area. The high magnetization contrast in the NE and SE parts of the study area correlates with the migmatite-gneiss, biotite-granites, granites and basalts which are associated with high magnetic contrasts. Also, the high magnetization contrast in the NW part of the area correlates with basalt and the biotite-granite. However, the predominant low magnetization contrast observed in the western half does not correlate with the basic igneous rock

scholarly journals Preliminary Investigation of Seismicity in Parts of North Central Nigeria, Using High Resolution Aeromagnetic Data

2020 ◽  
pp. 1-14
Author(s):  
A. Alkali ◽  
D. U. Alhassan ◽  
O. U. Akpan ◽  
A. A. Adetona ◽  
K. A. Salako ◽  
...  
Keyword(s):  
Fracture Zone ◽  
Preliminary Investigation ◽  
Aeromagnetic Data ◽  
Southeastern Part ◽  
North Central ◽  
North West ◽  
The North ◽  
Basement Rocks ◽  
First Vertical Derivative ◽  
Romanche Fracture Zone

Qualitative analysis of Aeromagnetic data of parts of north central Nigeria had been carried out with the aim to delineate seismic prone areas. The study area is bounded with latitude 9. 00o to 10. 00oN and longitude 7.00o to 9.00oE with an estimated total area of 24,200 km2. Vertical derivatives and upward continuation filters were used to enhances long wavelength anomalies which could give preliminary information about the magnetic structures present in the study area. The total magnetic intensity map shows both positive and negative anomalies with susceptibility ranging from 33487.7 nT to 33800.9 nT. The high magnetic susceptibilities dominated in the basement region around the north-eastern and north-western parts of the study area which corresponds to Naraguta, Jemma and Kafanchan area. Based on the geology of the area this is attributed to granite, schist and migmatite rocks. The low magnetic values are made of sediment deposition also dominates the south-western part of the study area, corresponding to Abuja and Gitata. The area with magnetic susceptibility values ranging between 33506.6 nT and 33653.8 nT indicates alluvium deposite around Bishini and Kachia area. Lineament from First Vertical Derivative trend in the northeast-southwest and east-west directions, which is an extension from Romanche Fracture Zone. Majority of this lineament trends in the same directions as the Romanche Fault Line which continues at 25 km and 30 km into n inferred closure within the study area which is trending along north-west direction. This, closure occurs probably because of the existence of the paleo fracture zone (Romanche Fracture Zone) within the study area. At 40 km and at 80 km a regional trend in the NE-SW direction in (porphyritic) basement rocks. At the northeast and southeastern part of the area which is made up of basement complex that corresponds to areas around Gitata, Kafanchaan and Jemma are prone to tectonic activities while the southwestern part of the area around Abuja is seismic free. It is suggested that those lineaments identified, most especially at the southeastern part could be the reason for the shaking of the subsurface which result into earth tremors.

scholarly journals Analysis of Aeromagnetic Anomalies of the North-eastern Nigerian part of the Chad Basin

2017 ◽  
Vol 4 (1) ◽  
Author(s):  
Kehinde Ishola ◽  
Blessing Okoye ◽  
Lukumon Adeoti ◽  
Kayode Oyedele
Keyword(s):  
Geomagnetic Field ◽  
Fourier Transformation ◽  
Magnetic Anomalies ◽  
Aeromagnetic Data ◽  
The North ◽  
Spectral Technique ◽  
North Eastern ◽  
Anomaly Map ◽  
East West

An appraisal of aeromagnetic data lying between Longitudes 110 00' 25.95''E - 110 30’ 15.1”E and Latitudes 110 30’ 7.59”N – 120 05’ 45.6''N has been carried out with a view to understanding structural trends of interest as well as determination of depth to magnetic sources giving rise to magnetic anomalies in the study area. To achieve the objectives of this study, the datasets were digitized along contours, corrected for the main geomagnetic field, re-gridded, and merged to generate magnetic structural anomaly map of the area. Also, from the aeromagnetic data, we used spectral technique based on Fourier transformation to estimate depths along some selected profiles on the residual anomaly map. The results show that the most pronounced structures are observed towards the southern and central parts of the study area signifying that majority of the magnetic anomalies trend in the Northeast-Southwest while the minor ones trend East-West direction. This suggests that the study area is intensely fractured with major regional faulting systems playing important role in entrapment and exploration of natural resources as well as understanding the hydrogeologic framework of the basin. The spectral analysis shows mainly two depth magnetic sources, the deeper sources with depths in the range of 1.34 to 3.42 km while the shallow sources are observed at depths between 0.33 to 0.91 km. Aeromagnetic data analysis over the basin shows that prominent anomalies have been identified and located.

scholarly journals Geochemistry and Petrogenetic Relationships Between Pegmatites and Host Rocks in the Keffi Area, North Central, Nigeria

2021 ◽  
Vol 6 (2) ◽  
pp. 42-49
Author(s):  
I. Y. Tanko ◽  
K. Dzigbodi-Adjimah
Keyword(s):  
Partial Melting ◽  
Systematic Study ◽  
Genetic Model ◽  
Small Scale ◽  
North Central ◽  
The North ◽  
Rock Types ◽  
Tectonic Environment ◽  
Area North ◽  
Host Rocks

Keffi pegmatites area which contains numerous mineralised and non-mineralised pegmatites lie between the Wamba pegmatite field to the NE and Nasarawa pegmatite field to the SW on the North Central Pegmatite belt of Nigeria. In Keffi area exploitation of deposits is currently being done by small scale miners, whose activities are haphazard and uncoordinated, because of that information on the geology and petrology that will enable a systematic study of the pegmatites in the area is scanty. Systematic geochemical investigations of the pegmatites and surrounding host rocks aimed at establishing petrogenetic relationships amongst the various rock types in the area were conducted. Major, trace and REE investigations of the pegmatites and associated granitoids have indicated petrogenetic relationships amongst the pegmatites and between the pegmatites and surrounding granitoids of Keffi area. Also, the variation diagram of major, trace and REE in whole rocks and K-feldspar samples show patterns which categorised the pegmatites of Keffi area into; (1) Non-mineralised, (2) intermediate and (3) mineralised pegmatites.  It was also deduced from the geochemical characteristics (variation diagrams in major and trace element, REE geochemistry and tectonic environment classification) that a genetic model based on the evolution of melt by partial melting of metasedimentary protolith during ultrametamorphic and deformational activities (anatexis) is proposed for the granite-pegmatite system of Keffi area. This information will be useful as guide for fruitful exploration of the pegmatites and serves as model for the exploitation of pegmatite veins in similar geologic settings.

scholarly journals Application of Aeromagnetic Data to Assess the Structures and Solid Mineral Potentials in Part of North Central Nigeria

2020 ◽  
pp. 11-29
Author(s):  
M. D. Tawey ◽  
D. U. Alhassan ◽  
A. A. Adetona ◽  
K. A. Salako ◽  
A. A. Rafiu ◽  
...  
Keyword(s):  
Structural Characteristics ◽  
Signal Amplitude ◽  
Analytic Signal ◽  
Aeromagnetic Data ◽  
Euler Deconvolution ◽  
North Central ◽  
Vertical Derivative ◽  
Magmatic Intrusions ◽  
First Vertical Derivative ◽  
Tilt Derivative

Assessment of the structures and solid minerals was carryout to investigate subsurface structural characteristics and mineralization potential zones within part of north-central Nigeria. The residual magnetic intensity data of the area was reduced to magnetic pole after which several source edge detection/interpretation with depth determination techniques including, analytic signal; tilt derivative; first and second vertical derivatives and Euler deconvolution were applied to the aeromagnetic data. From the analytic signal map, three magnetic zones were delineated. These are: low to relatively low magnetic zone (LM) with amplitude range from 0.003 to 0.009, moderate magnetic zone (MM) with amplitude 0.009 to 0.106 and those with amplitudes above 0.106 were products of later magmatic intrusions into host with fractures, faults and joints. Tilt derivative helped in delineating location and extent of edges of causative sources while Euler deconvolution helps in determination of boundary, depth and geometry of the structures. From first vertical derivative map, structures were found to have high lineament density around the central portion of the area and span toward the western end of the map were delineated. The lineaments mapped trending in the ENE-WSW followed by WNW-ESE with some NE-SW, NNE-SSW and NNW-SSE trends. The second vertical derivative (SVD) map also helped in delineating structures and possible mineralization zones that are pronounced within the study area, around high analytic signal zones. Delineated possible and favorable mineralization zones from second vertical derivative map correlate with portion of the study area with rocks showing high analytic signal amplitude suggesting the rocks to be of later magmatic intrusions where mineralization fluids solidify within the host rocks.

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