Delineation of Shallow Subsurface Structure by Azimuthal Resistivity Sounding and Joint Inversion of VES-TEM data: Case study near Lake Qaroun, El-Fayoum, Egypt.
An azimuthal resistivity survey was conducted at the transition zone between the desert area and the cultivated land near Lake Qaroun, Egypt. This area has been affected by an east-west trending fault system as indicated from the surface geology. Apparent resistivity values were plotted along azimuth on a polar diagram. Resistivity anomalies, for most of the AB/2 values with long axes strike in a direction parallel to the contact between the desert and cultivated lands, indicate the presence of electrical macro-anisotropy, mainly due to the faulting effect, at this area. Vertical electrical soundings (VES) and transient electromagnetic (TEM) measurements were conducted at eight stations along a line that crosses the boundary between the desert and cultivated land. Joint inversion of VES-TEM data was successfully used for identification of the subsurface litho-stratigraphic succession and demonstrated the effect of the fault zone on the investigated subsurface medium. Apparent anisotropy coefficients at all current electrode spacings were calculated plotted against AB/2 values and compared with the geoelectrical cross-section. The effect of the fault zone was detected at AB/2 spacings equal to 80 m and extended downward and is largely related to the depth of the fault, as indicated in the constructed cross section.
Azimuthal resistivity VES-TEM data Lake Qaroun Egypt
Usama Massoud Gad El Qady Mohamed Metwaly Fernando Santos
National Research Institute of Astronomy and Geophysics (NRIAG), Helwan, 11722, Cairo,Egypt. Center of Geophysics, Lisbon University (CGUL), 1749-016, Lisbon, Portugal
国际会议
The 19th International Workshop on Electromagnetic Induction in the Earth(第十九届国际地球电磁感应学术研讨会)
北京
英文
24-29
2008-10-23（万方平台首次上网日期，不代表论文的发表时间）