High-resolution aeromagnetic data over central Australia assist Grenville-era (1300–1100 Ma) Rodinia reconstructions

2008 ◽  
Vol 35 (1) ◽  
Author(s):  
Alan R. A. Aitken ◽  
Peter G. Betts
Keyword(s):  
High Resolution ◽  
Aeromagnetic Data ◽  
Central Australia

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.

AN AUTOMATIC METHOD OF COMPILATION AND MAPPING OF HIGH‐RESOLUTION AEROMAGNETIC DATA

Geophysics ◽  
1971 ◽  
Vol 36 (4) ◽  
pp. 695-716 ◽  
Author(s):  
B. K. Bhattacharyya
Keyword(s):  
High Resolution ◽  
Magnetic Measurements ◽  
High Sensitivity ◽  
Positional Error ◽  
Automatic Method ◽  
Aeromagnetic Data ◽  
Aeromagnetic Survey ◽  
Machine Method ◽  
Flux Gate ◽  
Definition Of

An automatic method has been developed for compilation of digital aeromagnetic data. This method has been applied to the data obtained during a high‐sensitivity aeromagnetic survey over an area in the Precambrian shield of northeastern Ontario in Canada. With this method, all points of intersection between traverse and base lines are determined automatically and adjusted within the limits of positional error for minimizing differences in magnetic values at the intersections. Then the data are corrected for diurnal variation and leveled to tie the magnetic measurements together. Next, the resulting total field values are contoured with a machine method at a scale of 1:25,000. For such a scale, the minimum contour interval that can be used in the present area is two gammas. However, because of the accuracy of the method of compilation, with a larger scale, it is possible to trace one‐gamma contours. The maps thus compiled have been compared with published aeromagnetic maps of data obtained with conventional flux‐gate and proton‐precession magnetometers. The new maps are vastly superior to the old ones for delineating trends, patterns, and fine features of available detailed geological maps. This superiority is mainly due to the excellent definition of small amplitude anomalies, some of only a few gammas in magnitude, on the high‐resolution magnetic maps.

scholarly journals Structural interpretation of High-resolution aeromagnetic data over the Dahomey basin, Nigeria: implications for hydrocarbon prospectivity

2021 ◽  
Vol 11 (4) ◽  
pp. 1545-1558
Author(s):  
E. M Okoro ◽  
K. M Onuoha ◽  
C. G Okeugo ◽  
C. I. P. Dim
Keyword(s):  
High Resolution ◽  
Oil And Gas ◽  
Low Cost ◽  
Sedimentary Basins ◽  
Data Interpretation ◽  
Aeromagnetic Data ◽  
Horizontal Derivative ◽  
Dahomey Basin ◽  
First Vertical Derivative ◽  
Total Horizontal Derivative

AbstractThe renewed quest to boost Nigeria’s dwindling reserves through aggressive search for oil and gas deposits in Cretaceous sedimentary basins has re-ignited the need to re-evaluate the hydrocarbon potentials of the Dahomey Basin. Aeromagnetic data are a low-cost geophysical tool deployed in mapping regional basement structures and determination of basement depths and sedimentary thickness in frontier basin exploration. In this study, high-resolution aeromagnetic (HRAM) data covering the Dahomey Basin Nigeria have been interpreted to map the basement structural configuration and to identify mini-basins favorable for hydrocarbon prospectivity. The total magnetic intensity grid was reduced to the equator (RTE) and edge detection filters including first vertical derivative (FVD), total horizontal derivative (THDR), tilt derivative (TDR) and total horizontal derivative of upward continuation (THDR_UC)) were applied to the RTE grid to locate the edges and contacts of geological structures in the basin. Depth to magnetic sources were estimated using the source parameter imaging (SPI) method. Data interpretation results revealed shallow and deep-seated linear features trending in the NNE-SSW, NE-SW, NW-SE and WNW-ESE directions. The SPI map showed a rugged basement topography which depicted a horst-graben architecture on 2D forward models along some selected profiles. Two mini-basins ranging in basement depths between 4.5 – 6.3km were mapped offshore of the study area. It appears the offshore Dahomey Basin holds greater promises for hydrocarbon occurrence due to the presence of thicker succession of sedimentary deposits in the identified mini-basins.

scholarly journals Interpretation of High Resolution Aeromagnetic Data for Hydrocarbon Exploration in Bornu Basin, Northeastern, Nigeria

2020 ◽  
Vol 63 (2) ◽  
Author(s):  
Adesoji Akanji ◽  
Oluseun Sanuade ◽  
Olawale Osinowo ◽  
Onyeka Okafor
Keyword(s):  
High Resolution ◽  
Hydrocarbon Exploration ◽  
Aeromagnetic Data
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