Estimation of 3D density distribution of chromites deposit using gravity data

Surface gravity data is inversed to recover subsurface 3D density distribution with two strategies. In the first strategy, we assumed wide density model bound to invert gravity data, and in the second strategy we carried out the inversion procedure by band limited density. We discretized the earth model into rectangular cells of constant and unidentified density. The number of cells was often greater than the number of observation points. Thus we have an underdetermined inverse problem. The densities were estimated by minimizing a cost function subject to fitting the observed data. The synthetic results show that the recovered model from the first strategy is characterized by broad density distribution around the true model, but the recovered model from the second strategy is closer to true models. To estimate the subsurface density distribution, we carried out inversion of gravity data taken over chromite deposit located at southern part of Iran. The recovered model obtained from the second strategy has appropriate agreement with previous studies.