oa Application of Gramian and Focusing Structural Constraints to Joint Inversion of Gravity and Magnetic Data

We develop and compare two methods of jointly inverting airborne gravity gradiometry (AGG) and total magnetic intensity (TMI) data in the presence of remanent magnetization. One is based on Gramian structural constraints, and the other uses a joint focusing stabilizer. Enhancing structural similarity between multiple geophysical models can help isolate mineralized targets. In the areas with remanent magnetization, one should invert not only for magnetic susceptibility, but for a 3D distribution of magnetization vector as well. The Gramian structural constraints enforce the correlation of the model gradients. The joint focusing stabilizer is implemented using minimum support approach, which forces a similarity of the shapes of the targets. We apply these novel joint inversion methods to interpretation of the airborne data collected over the Thunderbird V-Ti-Fe deposit in Ontario, Canada. By combining the complementary AGG and TMI data, we generate the jointly inverted models which provide a more consistent image of the geologic structure of the area.