Two-and-a-Half Dimension Gravity Modeling to Delineate the Structures of the Western Abu Gharadig Basin, Western Desert, Egypt

Abstract

abstract The present study is a trial to carry out 2½-dimensional gravity modeling to confirm the structures and tectonics of the western Abu Gharadig Basin, Western Desert, Egypt. This is achieved by a sequence of procedures, started by establishing the trends of six 2½-dimensional residual gravity models, most of them passing through the available control wells. Two-and-a-half-dimensional gravity modeling of mass distributions in the subsurface of the study area was performed on the significant residual anomalies of the area, which had been separated from the unwanted regional field. They were separated using the average power spectrum method available in the suite of programs provided by Geosoft (1994). Such 2½-dimensional models were constructed to reveal the dissecting structures and to subdivide the sedimentary sequence of the area into 10 time-rock and rock units (Paleozoic and Jurassic sequences, Alamein-Shaltut, Kharita, Bahariya, Abu Roash, Khoman, Apollonia, and Dabaa), in addition to the underlying basement complex. Some seismic sections were used to help constrain the construction of 2½-dimensional models. Two-and-a-half-dimensional gravity models were constructed after transferring the structural and geologic information (fault elements and depth values) of the two-dimensional gravity models to the base maps. In this way, 10 structural contour maps were established on the tops of the respective stratigraphic units. Generally, these maps reflect the considerable effect of the NE-SW and NW-SE trends as major directions of fracturing in the study area of the northern Western Desert of Egypt.