Gravity Field Interpretation for Subsurface Faults Detection in A Region Located SW- Iraq

Abstract

This research deals with processing and Interpretation of Bouguer anomaly gravity field, using two dimensional filtering techniques to separate the residual gravity field from the Bouguer gravity map for a part of Najaf Ashraf province in Iraq. The residual anomaly processed in order to reduce noise and give a more comprehensive vision about subsurface linear structures. Results for descriptive interpretation presented as colored surfaces and contour maps in order to locate directions and extensions of linear features which may interpret as faults. A comparison among gravity residual field , 1st derivative and horizontal gradient made along a profile across the study area in order to assign the exact location of a major fault. Furthermore, quantitative interpretations applied to residual field in order to detect the depth to the center of a major fault by adopting geometrical modeling. Interpretation results are helpful in delineating the exact locations of lateral changes within the subsurface rock densities around the subsurface major normal fault where sudden variations in gravity values take place. A major fault which extends in NW-SE direction detected at the eastern part of the study area with an approximate depth of 2.8 km to its plane center.