Gravity anomalies of strike limited listric fault sources with analytically defined fault planes and arbitrary density contrast variations with depth

Abstract

A method to compute the theoretical gravity anomalies of strike limited listric fault sources is presented along with a relevant computer code, GRLSTRCFLT. The fault plane of a listric fault structure is described with a polynomial function of arbitrary degree. Further, the density contrast within the structure is presumed to be varying randomly with depth comprehending the geological settings where the detached downthrown block of a fault structure is assumed consisting of both high and low density formations. The expression for the gravity anomaly to realize forward modelling is derived in the space domain using both analytical and numerical approaches. The validity and efficacy of the method is demonstrated with a set of synthetic fault models. The gravity anomaly computed at two selected offsets across the fault structure in either case reveals the fact that the magnitude of the anomaly is dependent on the offset of the profile. © 2010 European Association of Geoscientists & Engineers.