Source structures at Pre-Miocene level as deduced by gravity stripping

Abstract

The lowermost portion of the sedimentary section in Gulf of Suez basin is mostly of low resolution and hardly interpret. This may be attributed to the bad seismic reflection that stops at a certain limit and fails to reach the deep settings, or due to non-coverage of boreholes. Herein, the gravity data was reinterpreted utilizing the stripping technique as an alternative tool to overcome the seismic failure. The process simply consists in calculating the gravity effects of the shallow rock-units and removing them from the Bouguer map, then in analyzing the remaining gravity. The ordinary seismic analysis was performed to control the geometry of the Miocene-Post Miocene formations, and density was driven from boreholes. Further analyses were done on the stripped map to obtain details about the deep sources. Generally, the study suggests a complex structure at Pre-Miocene level more than that of Miocene. It delineates two main troughs; Miocene basin to the east and Pre-Miocene basin (involves three sub-basins) to the west, separated by a structural ridge, all are northwesterly oriented. The basement is very disturbed by cross-faults, with no evidence support presence of igneous intrusions along. Two different forces (NW-SE compression and NE-SW tension) affected the region.

The Jurassic and Deep Structures Inferred from Gravity Data Depending on Stripping Technique for The Uppermost Layers in Central and Southern Iraq

“…The Cenozoic and Mesozoic rocks' gravity effects were stripped, and the gravity map of the deeper gravity sources was obtained [6]. [7] determined the gravity effect of the Miocene rocks and stripped this effect from the Bouguer gravity map to investigate the deep complex structures. They delineate two main troughs separated by a structural ridge [7].…”

“…[7] determined the gravity effect of the Miocene rocks and stripped this effect from the Bouguer gravity map to investigate the deep complex structures. They delineate two main troughs separated by a structural ridge [7]. This study attempts to use the stripping technique to eliminate the gravity effect of shallow sources in order to investigate the deep structures in central and southern Iraq.…”