Curie depth estimated from high-resolution aeromagnetic data of parts of lower and middle Benue trough (Nigeria)
- PDF / 3,798,445 Bytes
- 17 Pages / 439.37 x 666.142 pts Page_size
- 103 Downloads / 219 Views
Curie depth estimated from high‑resolution aeromagnetic data of parts of lower and middle Benue trough (Nigeria) Mukaila Abdullahi1 · Raj Kumar2 Received: 17 November 2019 / Accepted: 17 August 2020 © Akadémiai Kiadó 2020
Abstract To quantitatively understand the geodynamic process of a region, study of geothermal parameters underneath the earth surface is very paramount. Curie depth can be an alternative to delineate geothermal parameters. In the present study, we estimated Curie depths from the power spectra of 25 equally window sizes areas/points with 50% overlap extracted from high-resolution aeromagnetic anomalies of parts of lower and middle Benue Trough, Nigeria using modified centroid method based on fractal distribution of magnetic sources. Curie depths with associated uncertainties calculated from the region under study are between 11 ± 2 and 27 ± 2 km. The shallowest depth (11 ± 2) km is calculated around the area of Abakaliki whereas the deepest depth is calculated around Otukpa area of Anambra basin. The shallowest Curie depth as calculated is related with the Abakaliki anticlinorium while the deepest result is in connection with the Anambra basin. These suggest that different geological structures and magnetic anomalies (i.e. high or low magnetic anomaly) influenced the calculated Curie depth results. In the region, it is noted that lower Curie depths (14–18 km) are recorded over the basement rocks and Curie depths between 18 and 22 km within zones of volcanoes. The interpretation hypothesized presence of underplating in the crust and possibly mantle plume as a result of the Mesozoic–Cenozoic volcanic magmatism (magmatic centers) mostly basalts distributed and scattered in the region. It has also been hypothesized that the uncertainties calculated (± 0.2 to ± 5.0) in the region correlate more strongly with the geology, tectonic structures and type of anomalies than estimated Curie depths. Keywords Geothermal · Curie depth · High-resolution aeromagnetic data · Modified centroid method · Benue trough (Nigeria)
* Mukaila Abdullahi [email protected] 1
Physics Unit, Department of Science Laboratory Technology, Modibbo Adama University of Technology, P.M.B. 2076, West Africa, Yola, Nigeria
2
Shillong Geophysical Research Centre, Indian Institute of Geomagnetism Mumbai, Shillong 793005, India
13
Vol.:(0123456789)
Acta Geodaetica et Geophysica
1 Background of the study The Benue trough (Fig. 1) in Nigeria, West Africa, is an important rift system in the country. The trough as a region is an elongated rift system oriented roughly NE-SW whose development has been very closely associated with the separation of Africa from South America and the opening of Atlantic Ocean (Carter et al. 1963; Cratchley and Jones 1965; Wright 1976; Ajayi and Ajakaiye 1981; Adighije 1981; Agagu and Adighije 1983; Ofoegbu 1984; Benkhelil 1989; Ogunmola et al. 2016; Abdullahi et al. 2019b). Thermo-tectonic activities of mid-Santonian age are responsible for the extension of the trough westward and hence t
Data Loading...
