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

Abstract

Aeromagnetic data for center-east Cameroon between the latitudes 3.5˚ to 4.5˚N and longitudes 12˚ to 12.5˚E are used to further study the subsurface area of this part of the geological Province of Central Africa and the Congo Craton. The GIS and GEOSOFT v6.5 softwares are used to treat the data. This analysis enabled us to explore our study area from surface right to the base. The Tilt Angle method is used to delineate geological structures and to estimate the depth. The Euler's deconvolution method is used to estimate the specific depth of structural contacts. We estimate the northern boundary of the Congo Craton and southern boundary of the Pan-African starting from 3˚7'N of West to 3˚75'N of East. Its depth is estimated around 2.6 km for deep and 0.1 km for shallow while the direction is WSW-ENE and the NW slope varies from 30˚ to 60˚. We obtain that main and minor lineaments exist throughout, from the surface to the base of the area with their principal direction being SW-NE. We also obtain the vertical gradient contact and the quasihorizontal contact. This is proof of the subduction of the Pan-African belt under the Congo Craton due to the intense collision which caused the rejuvenation of the crust. The main consequence of this collision is the formation of pudding 926 International Journal of Geosciences and fold structures, beginning from the superficial part right to the base and which caused the intrusion of schistose, chlorite-schist, quartzite in the micaschist and the intrusions of gneiss and garnetiferous schist in the migmatite. In our study, we highlight the presence of 37 major and 523 minor lineaments that localize the circulation of minerals. The probable slope of the lineaments in the northern part of the region varies from 30˚ to 60˚ in a SE direction while in the southern part, and it varies from 30˚ to 60˚ in a NW direction.

Evidences by Multiscale Analysis and 2D3/4 Models from the Magnetic Anomalies and Iron Mineralization (BIF) over the DJADOM-ETA Area, Southeastern Cameroon

“…The structural map shows a network of lineaments in our study area can be considered as the extension of the faults revealed by [5] in the eastern part of our study area. The continuity of this prolongation Northwards of our zone is documented in the audio magnetotellurics study done by [6] and in aeromagnetic study done by [7]. The structural features that trend in the same direction are likely to be produced by the same tectonic processes.…”

“…The northern boundary of the Congo Craton is defined to be starting from 3˚7'N of West to 3˚75'N of East. Its depth is ranged from 2.6 km to 0.1 km with a an ENE-WSW direction and NW slope varying from 30˚ to 60˚ [7].…”

“…The study realized by [1] is adjacent to [5] where the same directions of lineaments are signaled in the eastern part of our study area. The continuity of the prolongation Northwards of our zone is documented in an audio magnetotellurics and in aeromagnetic analyses carried out respectively by [6] and [7]. Magnetic minerals can be mapped from the surface to greater depths in crustal rocks depending on the dimension, shape, and magnetic properties of the rock.…”

Aeromagnetic Data Modeling for Geological and Structural Mappings over the DJADOM-ETA Area, in the Southeastern Cameroon

“…This The structural map leads to put in evidence a network of faults in the study area and thus to show that the network of faults in the adjacent Eastern zone of this area is prolonged into the current zone [7]. The continuity of this prolongation Northwards of this zone is highlighted in the audio-magnetotelluric [16] and in aeromagnetic [17] studies. The geometrical description of this structure suggests an open synclinal transposed on vertical foliations: the major fault at the DJADOM axis is quasi-parallel to the Northern limit of the CC and parallel to the Sanaga Fault (SF) and the Central Cameroon Shear Zone (CCSZ).…”

Inferring the Subsurface Basement Depth and the Contact Locations from Aeromagnetic Data over Loum-Minta Area (Centre-East Cameroon)

“…Many researchers [2] [3] used source parameter imaging (SPI) to determine the depth to basement surface. The aeromagnetic method has been used in many geophysical studies in Cameroon [4]- [11] to map tectonic structures such as faults, lineaments, fractures and to highlight non-flush geological structures.…”