A study of complex substructures in a foothill belt of northwestern Taiwan using two-dimensional gravity multiple-source model inversion

The goal of this paper is to improve the capability of gravity inversion assessment of complex structures using a multiple-source model as indicated by a study of a foothill belt of northwestern Taiwan. In this study, a gravity inversion computer program is applied based on research developed by Tsai, which contains a Marquardt inversion algorithm for mathematical calculations and incorporates constraints on geological parameters. The computed and modified geological parameters are transformed into coordinates. The response of a proper geological model is calculated using the Talwani technique. The method is applied to a field example in a foothills belt of Taiwan that possesses complex subsurface structures. The density profile from 2D gravity data, obtained using our inversion computer program, reveals a good correlation with the geological model obtained from seismic, borehole, and geologic data. Furthermore, potential hydrocarbon traps associated with some of the interpreted geological structures (where no seismic data are available) in the eastern and western seismic sections are being evaluated and assessed for possible future development. This profile highlights features that are important to a good understanding of an area with complex subsurface structures. It also helps to define subsurface geology and assess potential hydrocarbon traps. This two-dimensional multiple-source model gravity inversion algorithm provides a powerful tool to interpret the gravity data in this study.