Tracing the manganese ore accumulations in Sinai Peninsula, Egypt, using magnetic method

Abstract

In this study, an ideal area known for manganese ore accumulations in Sinai Peninsula has been investigated in detail using geological, laboratory analyses and magnetic tools. The main target is to establish a relationship between the ore accumulations, geology and the subsurface faults (shear structures) which are extending to deeper depths in the basement rocks of the study area and then use it as key for the un-explored areas in the Sinai Peninsula. To achieve this target, a detailed land magnetic survey has conducted to the selected area and later extended to include the whole peninsula. The geological data have obtained from the drilled wells and Egyptian Geological Survey and Mining Authority of Egypt. The geological investigations are including studying the surface geology and interpretation the well logging data to trace the ore mineral distributions along the different depths in the peninsula. The magnetic data has processed using a series of techniques, namely, second vertical gradient, 3D analytical signal, trend analyses, Euler deconvolution, Werner deconvolution and 3D modeling techniques. Also, the Curie depth method has applied along more than 31 grids forming the magnetic map of Sinai Peninsula to study the behavior of geothermal solutions and their effects in the host country rocks and their relationship to the existing ore accumulations. Furthermore, more than 300 rock samples have collected from different sites covering Sinai Peninsula area. These samples were subjected to laboratory measurements of the magnetic susceptibility. The results show that the Curie magnetic depth confirms that these shear structures at the intersection points are extended to deep depths which make as a pass way for the hydrothermal solutions into the host rocks which are probably forming the ore accumulations. The ore mineral accumulations appear to be confined to the carbonate rocks and to the shear zones intersections of the structures which are trending NW–SE and NE–SW directions. The depth to these accumulations was found to be ranging between 300 m at the southern parts to more than 3 km at the northern parts of the Sinai Peninsula. The measured magnetic susceptibility values range between 0.4 SI and 1.8 SI. Five new areas namely; Sharm El Sheikh, Wadi Zaghrah, SW Taba, Libni and Maghara can be prospected in the Sinai Peninsula have the similar conditions which are existing at Abu Zneima known mine area.