Wavelet analysis of residual gravity anomaly profiles: Modeling of Jharia coal basin, India

Abstract

In recent years, the wavelet transform has widely been used in gravity data processing and interpretation due to the good property of multi-scale analysis, and it has become an important method for mapping the crustal thickness. In this paper, an attempt is made to map the thickness of sedimentary basin (Jharia coal basin) using continuous Wavelet transform (CWT) of gravity data. As gravity anomalies map is corresponding to different geological object with different scales buried at depth. CWT technique provides source parameters such as the location, depth, structure and geometry of geological bodies and interfaces in an easy and effective way without any priori information and thus can be further used for modelling. This observation was demonstrated with a synthetic gravity data and also applied to field residual gravity anomalies over Jharia coal basin. In order to verify the results made by CWT, Euler Deconvolution Method (EDM) and Tilt-Depth Method (TDM) were also utilized to estimate the depth of the sedimentary basement. We found that CWT gives satisfactory and better results than the EDM and TDM, and the obtained results are well correlated with known models. All the above advance techniques provide consistent results. Therefore CWT offers primary information of major coal thickness that provides a basis for modeling of gravity anomaly over Jharia coal basin.