Delineating the regional structures and depth of basement rocks using the gravity data analysis at west Assiut, Egypt.

Document Type : Original Article

Authors

1 Geology Department, Faculty of Science, Al-Azhar University (Assiut Branch), Egypt.

2 Earthquake Research Center, National Research Institute of Astronomy and Geophysics (NRIAG)Aswan, Egypt

Abstract

The purpose of the gravity approach is to detect subsurface structures using disturbances in the earth's gravitational field produced at the surface. Gravity was used to outline the subsurface structures; due to the study area includes many huge national projects such as Assiut Cement, New Nasser City and Assiut International Airport, It is important to assess the subsurface geological structures in the area. Bouguer gravity data of Egyptian General Petroleum Company (EGPC 1984) was used to performed Bouguer gravity anomaly map at the study area to start the gravity interpretation by separation of the residual anomaly from regional anomaly and then the data was filtered by mathematical methods called Tilt derivative (TDR), low pass, high pass and downward continuation to apply the gravity filtering using commercial software Oasis Montaj 2015. The Bouguer, residual and regional maps depict multiple structural features (mainly normal faults) with varied tendencies, such as E-W, NE-SW, and NW-SE. The source body derived from these data had depths varying from less than 2000 m to more than 4000 m. The basement depth in the research area below sea level varies between 2160 m and more than 2900 m.

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 [1] Oasis Montaj Programs. Geosoft mapping and processing system: version 8.3.2 (HJ), Inc Suit 500, Richmond St. West Toronto, ON Canada 2015, N5SIV6.
[2] Hare J, Ferguson J, Aiken C, Brady J. The 4-D microgravity method for waterflood surveillance: A model study for the Prudhoe Bay reservoir, Alaska. GEOPHYSICS. 1999; 64(1):78-87.
[3] Mohamed A, Ella E. Magnetic Applications to Subsurface and Groundwater Investigations: A Case Study from Wadi El Assiuti, Egypt. International Journal of Geosciences. 2021; 12(02):77-101.
[4] Atya M, Meneisy A, Bedair S. Integration of electrical resistivity and time-domain electromagnetic to investigate the subsurface stratigraphic conditions at Assiut Power Plant, Assiut, Egypt. NRIAG Journal of Astronomy and Geophysics. 2020; 9(1):471-482.
[5] Omara S, El-Tahlawi MR, Hafez H. The geology of the environs of Assiut. Bull. Soc. Geograph. Egypt. 1970; 43.
[6] Arfa M, Elshafei F. Soil surface seismic hazard maps for the proposed site of Nasser New City, West Assiut, Egypt. Arabian Journal of Geosciences. 2021; 14(12).
[7] Said R. The Geology of Egypt. Elsevier Pub. Amesterdam, New York, 1962, 377.
[8] Youssef MM, Riad S, Mansour HH. Surface and subsurface structural study of the area around Assiut, Egypt. Bulletin, Faculty of Science, Assiut University. 1977; 6(2):293-306.
[9] Said R. The geological evaluation of the River Nile. Springer Verlage 1981; 138.
[10] Nakhla A, Kenneth NM, Glen TP. Aeromagnetic evidence for a deep sedimentary basin near Assiut, Egypt. Egyptian General Petroleum Corporation. 1986:244-59.
[11] Rizkalla IR. Interpretation of Aero-Magnetic Data around Assiut Area, Eastern Desert, Egypt. In Egyptian Geological Society Proceeding of the 7th Annual Meeting, Cairo 1989 Mar (pp. 65-76).
 [12] CONOCO. Geological map of Egypt, scale 1:500, 000, Cairo, Egypt 1987.
[13] Egyptian Geological Survey and Mining Authority (EGSMA). Geological Map of Egypt 1981. [14] EGPC (Egyptian General Petroleum Corporation). Aeromagnetic survey of north Eastern Desert and Gulf of Suez, Western Geophysical Company of America. 1983
[15] Alrefaee H, Soliman M, Merghelani T. Interpretation of the subsurface tectonic setting of the Natrun Basin, north Western Desert, Egypt using Satellite Bouguer gravity and magnetic data. Journal of African Earth Sciences. 2022; 187:104450.
[16] Spector A, Grant F. STATISTICAL MODELS FOR INTERPRETING AEROMAGNETIC DATA. GEOPHYSICS. 1970; 35(2):293-302.