Gravity Field Interpretation for Faults Detection At Al-Ghadaf Valley West Razazzah Lake – Iraq

Abstract

This research deals with the processing and interpretation of Bouguer gravity anomaly field for Al-Ghadaf valley region, which located to the west of Razazzah Lake of Iraq. Total Bouguer field gridded manually and input to computer software to get processed digitally in order to detect the subsurface structural setting which was responsible of producing the positive gravity anomaly in the middle of the region. Regional gravity field was conducted by using the polynomial regression graphical method. Residual field was conducted mathematically and was helpful in detecting the boundaries of abrupt change in gravity or density at the sedimentary cover depths. The abrupt density variation linear features are mostly representing faults. A directional 1stderivative filtering applied on the residual field in order to assure the locations of linear features (faults) which were showing abrupt variation in density. Quantitative interpretation achieved for the profiles (A-B and C-D) which were taken for the residual gravity field and depth to the center of the causative body was calculated by applying the X1/2 method to be about (21-25 Km).