Analysis of magnetic data over part of the Younger Granite Province of Nigeria

Autor: Ofoegbu, Charles O., Hein, Karin
Zdroj: Pure and Applied Geophysics; July 1991, Vol. 136 Issue: 2-3 p173-189, 17p
Abstrakt: The results of a magnetic study of part of the Younger Granite Province of Nigeria are presented here. Spectral analysis of the magnetic anomalies over the area has been carried out in an effort to estimate the depth to magnetic sources. Average magnetic source depth of 286 m has been obtained for the area and this is thought to be related to the depth to the top of the main anomalous structures in the area. Observed magnetic anomaly profiels taken across the area have been interpreted in terms of arbitrarily shaped bodies—whose existence was confirmed by 3-D Hilbert transformation-using nonlinear optimization techniques. The modelled bodies occur at depths of 200–760 m and have magnetizations of 0.29–0.47 A/m. The results from the analysis of the magnetic field are discussed in relation to the results from previous gravity studies over the area and the mode of emplacement of the Younger Granites.
Databáze: Supplemental Index