Using Filon Fourier Spectral Analysis Technique for Filtering of Aeromagnetic Data and Outlining Subsurface Structures of Helma-Madrakah Area, Kingdom of Saudi Arabia

Abstract

ABSTRACT. The Helma-Madrakah area lies in the northern part of the Makkah quadrangle located in the southern part of the Hijaz region, western Saudi Arabia. The area is bounded by longitudes 39º30′N and 39º54′E and latitudes 21º45′N and 22º00′N; i.e., north of Makkah AlMukarramah and north-east of Jeddah.The present study deals with the interpretation of aeromagnetic data, which conducted by Aero-Service Corporation in the period 1965-1966 to depict subsurface regional and residual subsurface structural features. The Filon Fourier spectral analysis technique is used to determine average depths to the causative bodies (6.0, 1.2 and 0.7 km) of regional and residual anomalies. Special windows are designed and used to calculate the regional and residual components at each point along several profiles. Accordingly, the regional and residual magnetic maps of the area under study were produced.The regional magnetic contour map indicates the rocks in the eastern part of the area to be more acidic than these in the western part.The residual magnetic contour maps, on the other hand, show a number of higher frequency dipole magnetic anomalies. This reveals that the near surface rocks contain a certain amount of magnetic minerals. Therefore, the locations of these anomalies are considered very important for mineral exploration.

Interpretation of aeromagnetic data over Abeokuta and its environs, Southwest Nigeria, using spectral analysis (Fourier transform technique)

“…The values of ( [18] on aeromagnetic data over Longituda Plateau and its environment, where the mean depth of the shallow sources was 0.591 and 2.26 km was the depth to deeper magnetic sources. Hassanien [19] used Filon Fourier spectral analysis and obtained the depths of 0.7 km and 6.0 km for the residual and regional anomalies, respectively. However, the study carried out by Nwankwo et al [20] on sedimentary formation of Northern Nupe Basin found depth to magnetic basement to vary from 0.52 to 4.38 km, while a depth range of 0.24-1.74 km was attributed to shallow sources.…”