scholarly journals Interpretation of Aeromagnetic Data of Part of Gwagwalada Abuja Nigeria for Potential Mineral Targets

2021 ◽  
Vol 3 (4) ◽  
Author(s):  
Priscillia Egbelehulu ◽  
Abu Mallam ◽  
Abel. U. Osagie
Keyword(s):  
Depth Map ◽  
Analytic Signal ◽  
Maximum Depth ◽  
Geological Survey ◽  
Aeromagnetic Data ◽  
Euler Deconvolution ◽  
Deconvolution Technique ◽  
Potential Mineralization ◽  
Susceptibility Contrast ◽  
Signal Filter

This study analyzes aeromagnetic data over a section of Gwagwalada in Abuja. The data were obtained from the Nigerian Geological Survey Agency acquired at 100 m terrain clearance. The study area spans longitudes 7.0875 E to 7.1458 E and latitude 8.9625 N to 9.0 N (about 27 km2). The dataset was reduced to the equator (RTE) and downward continued by 50 m. Analytic signal filter was applied on TMI-RTE grid to detect the edges of the magnetic bodies present. The structure was observed to trend NE-SW. The CET lineament map reveals intersections such as junctions and corners on the map. This revealed structure liable for potential mineralization zone. Euler deconvolution technique applied over the transformed dataset ascertain the location and depth of the structure,having a maximum depth of about 421 m and a minimum of about 59 m.Variation in magnetic depth and susceptibility contrast is specified by the gridded SPI depth map.

Application Effect Analysis of Magnetic Gradients Data Continuation from Undulate Surface to Plane

2013 ◽  
Vol 779-780 ◽  
pp. 643-646
Author(s):  
Hai Xia Li ◽  
Hai Long Yu ◽  
Xiao Ling Zhang
Keyword(s):  
Model Test ◽  
Analytic Signal ◽  
Deconvolution Method ◽  
Euler Deconvolution ◽  
Effect Analysis ◽  
Method Calculation ◽  
Magnetic Source ◽  
Deconvolution Technique ◽  
Before And After ◽  
Magnetic Gradients

Application effect of magnetic gradients data continuation from undulate surface to plane has been analyzed by model test. The gradient data of before and after the processing was used for the analytic signal and the Euler deconvolution method calculation respectively, comparing the calculated results show that the maxima of analytic signal calculated by gradients anomaly on undulate surface deviate obviously from the center location of the prism magnetic source, and the position of prism boundaries are not clear. However, the analytic signal calculated by gradients anomaly after continuation from undulate surface to plane can be successfully used to estimate the center and boundaries position of prism. The solutions of Euler deconvolution method calculated by gradients anomaly on undulate surface are dispersive, the solutions calculated by gradients anomaly after continuation from undulate surface to plane are relatively clustering, and can outline clearly the positions of prism corners. The results demonstrate that continuation from undulate surface to plane processing of gradients anomaly can improve the application effect of analytic signal and Euler deconvolution technique.

scholarly journals Thermomagnetic Features of Crust in Southern Parts of the Structural Provinces of Tocantins and São Francisco, Brazil

2013 ◽  
Vol 2013 ◽  
pp. 1-8
Author(s):  
Suze Nei P. Guimaraes ◽  
Valiya M. Hamza
Keyword(s):  
Regional Scale ◽  
Analytic Signal ◽  
Magnetic Characteristics ◽  
Data Sets ◽  
Aeromagnetic Data ◽  
Euler Deconvolution ◽  
Spatial Dimensions ◽  
Magmatic Intrusions ◽  
Tertiary Period

In the present work we report results of a regional scale investigation of the thermal and magnetic characteristics of the crust in the southern sector of the geologic provinces of Tocantins and São Francisco, Brazil. Updated compilations of aeromagnetic and geothermal data sets were employed for this purpose. Use of such techniques as vertical derivative, analytic signal, and Euler deconvolution in analysis of aeromagnetic data has allowed precise locations of the sources of magnetic anomalies and determination of their respective depths. The anomalies in the Tocantins province are considered as arising from variations in the magnetic susceptibilities and remnant magnetizations of alkaline magmatic intrusions of the Tertiary period. The lateral dimensions of the bodies are less than 10 km, and these are found to occur at shallow depths of less than 20 km. On the other hand, the anomalies in the cratonic areas are related to contrasts in magnetic properties of bodies situated at depths greater than 20 km and have spatial dimensions of more than 50 km. Analysis of geothermal data reveals that the cratonic area is characterized by geothermal gradients and heat flow values lower when compared with those of the Tocantins province.

Magnetic gradient techniques on digitized aeromagnetic data of Ibadan area, south-western Nigeria

2013 ◽  
Vol 5 (3) ◽  
Author(s):  
Biodun Badmus ◽  
Musa Awoyemi ◽  
Olukayode Akinyemi ◽  
Ganiyu Saheed ◽  
Oluwaseun Olurin
Keyword(s):  
Magnetic Field ◽  
Signal Amplitude ◽  
Analytic Signal ◽  
Maximum Depth ◽  
Horizontal Gradient ◽  
Aeromagnetic Data ◽  
Magnetic Gradient ◽  
Gradient Magnitude ◽  
Local Wavenumber ◽  
Intensity Magnetic Field

AbstractLocations and depths to magnetic contacts were estimated from the total intensity magnetic field using the Horizontal Gradient Magnitude (HGM), Analytic Signal Amplitude (ASA) and Local Wavenumber (LWN) methods. Aeromagnetic data from the Ibadan area, in south-western Nigeria, were analyzed to estimate depths to magnetic sources as well as source locations. The minimum/maximum depth limits of the HGM and LWN are relatively close and comparable, while shallow source depths limits are greater than expected in the ASA method when compared with the HGM and LWN functions.

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.

scholarly journals Analytic Signal Depth from High Resolution Aeromagnetic Data over the Gongola Basin Upper Benue Trough Northeastern Nigeria

2021 ◽  
Vol 25 (4) ◽  
pp. 585-590
Author(s):  
H. Musa ◽  
N.E. Bassey ◽  
R. Bello
Keyword(s):  
High Resolution ◽  
Magnetic Structure ◽  
Horizontal Cylinder ◽  
Analytic Signal ◽  
Aeromagnetic Data ◽  
Polynomial Fitting ◽  
Benue Trough ◽  
Local Maxima ◽  
Depth Determination ◽  
Programming Software

The study of high-resolution aeromagnetic data was carried out over the Gongola basin, upper Benue trough, northeastern Nigeria, for analytic signal depth determination. Total intensity magnetic map obtained from the data using the Oasis Montaj TM programming software was used to get the residual map by polynomial fitting, from where the analytic signal was obtained with the use of anomaly width at half the amplitude (X1/2). This was used to carry out depth estimations over the study area. The results showed that it peaks over the magnetic structure with local maxima over its edges (boundaries or contact), and the amplitude is simply related to magnetization, likewise results also showed that the depth estimates were in the range of 1.2 to 5.9 km and were calculated for contact, dyke/sill and horizontal cylinder respectively. The lowest values are from DD profiles, while the highs are from AA profiles. This work is important in identifying dykes, contacts and intrusives over an area.

scholarly journals Combination of Tilt-Angle and Euler Deconvolution Approaches to Determine Structural Features from Aeromagnetic Data Modeling over Akonolinga-Loum Area (Centre-East, Cameroon)

2017 ◽  
Vol 08 (07) ◽  
pp. 925-947 ◽  
Author(s):  
Justine Yandjimain ◽  
Théophile Ndougsa-Mbarga ◽  
Arsène Meying ◽  
Marcelin Bikoro Bi-Alou ◽  
Paul Claude Ngoumou ◽  
...  
Keyword(s):  
Tilt Angle ◽  
Data Modeling ◽  
Structural Features ◽  
Aeromagnetic Data ◽  
Euler Deconvolution

Balancing images of potential-field data

Geophysics ◽  
2009 ◽  
Vol 74 (3) ◽  
pp. L17-L20 ◽  
Author(s):  
G. R. Cooper
Keyword(s):  
Potential Field ◽  
Field Data ◽  
Large Range ◽  
Signal Amplitude ◽  
Analytic Signal ◽  
Aeromagnetic Data ◽  
Hilbert Transforms ◽  
Potential Field Data ◽  
Total Gradient ◽  
Data Source

Horizontal and vertical gradients, and filters based on them (such as the analytic signal), are used routinely to enhance detail in aeromagnetic data. However, when the data contain anomalies with a large range of amplitudes, the filtered data also will contain large and small amplitude responses, making the latter hard to see. This study suggests balancing the analytic signal amplitude (sometimes called the total gradient) by the use of its orthogonal Hilbert transforms, and shows that the balanced profile curvature can be an effective method of enhancing potential-field data. Source code is available from the author on request.

The Use of Euler Deconvolution Technique in the Estimation of Depth to Magnetic Source Bodies around the Schist Belt Parts of Kano State, Nigeria

2021 ◽  
Vol 14 (1) ◽  
pp. 19-23
Keyword(s):  
Depth Estimation ◽  
Magnetic Survey ◽  
Schist Belt ◽  
Euler Deconvolution ◽  
Depth Estimate ◽  
Paper Detail ◽  
Magnetic Source ◽  
Deconvolution Technique ◽  
Proton Precession Magnetometer ◽  
Ground Magnetic

Abstract: Depth estimation of magnetic source bodies in parts of the Schist Belt of Kano, using Euler Deconvolution is presented in this paper. Detail ground magnetic survey was carried out using SCINTREX proton precession magnetometer to produce the Total Magnetic Intensity (TMI) map and consequently the residual map. The TMI ranges from 34,261 nT to 34,365 nT, while the residual field ranges from -160 nT to 115 nT. The depth estimate for contacts ranges from 6.5 m to 39.8 m, while that of dyke ranges from 8.9 m to 51.3 m. The depth estimation presented in this work is compared with the results of aeromagnetic study carried out in the same area and found to agree fairly well. Further, this also ensures the validity of aeromagnetic investigation in such applications. Keywords: Contacts, Dykes, Euler Deconvolution, Schist Belt. PACS: 91.25.F and 91.25.Rt.

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