Aeromagnetic data for mapping geologic contacts at Samr El-Qaa area, North Eastern Desert, Egypt

Abstract

Delineating the edges of different magnetized sources represents a fundamental tool for interpreting and mapping rock boundaries of magnetic data. The present study deals with the enhancement of reduced to the pole map (RTP) of Samr El-Qaa area, North Eastern Desert, Egypt, to map deep and surface geologic contacts. The edge detection of geologic contacts is ensured by the upward continuation of reduced to the pole data at an altitude of 3 km, followed by the calculation of theta derivative and horizontal tilt angle derivative (HTAD) for RTP and upward continuation (3 km). The results obtained from the application of these techniques showed that the theta derivative delineates RTP source edges well, but the response of deeper sources is diffused. While HTAD presented well, responds to shallow and deep sources and also the edges of the sources were delineated well. HTAD showed a much sharper gradient over the edges of the magnetized sources at Samr El-Qaa area. The interpreted structural trends derived from shallow and deep Theta and HTAD maps of Samr El-Qaa territory illustrated that the most shallow dominant trends are NNE, NE, N-S, NNW, WNW, E-W and NW directions. While the deep structural ones are the ENE, NW, N-S, and E-W directions. This approach for edge detection used in this study is comprehensively applicable to other portions of the Egyptian Eastern Desert and other areas with alike geologic conditions around the world to give much sharper gradient over the edges of the magnetized sources which can be used for mineral and oil/gas exploration.