Simulation and Modeling Techniques in Gravity Inversion Analysis: Variable Density Contrasts, Contact Surfaces and Error Corrections in Gravity Analysis

Quantitative determination of variable or differential density contrasts and position of contact surfaces in an intermediate horizontal layer for a sub-surface structure has been demonstrated. In particular a sub-surface dipping dike with apriori depth-dependent density contrasts was adopted in the forward modeling. Since geophysical fields observations are not error-free, the possible errors and error effects in the determination of differential density contrasts and positions of contacts surface has too been undertaken. Errors and error effects in disturbing masses considered were due to deviations due to inaccurate average depth of layer, distortions due to assigned layer thickness or assumed density, top surface only being identical to observations surface and layer being approximated as surface covered with a loaded mass. Height error limits on height measurements were too investigated using the geological materials modeled for a sub-surface dipping dike. The simulation and modeling technique adopted here in the gravity inversion should be useful to geologists and geophysicists in their prospecting applications in petroleum and geothermal exploration, mining etc.