Theta-Depth method for the interpretation of potential field data

The Theta map is a commonly used tool to detect edges of subsurface geological bodies using potential field (gravity and magnetic) data, which is the ratio of function of horizontal derivative to vertical derivative of gravity or magnetic anomalies. Although the effect of calculation of shallow geological body edges by this method is good, it is not successful in probing the deep geological body edges process due to the convergence of the conversion process that leads inaccurate calculation. To solve this problem, we proposed the Theta-Depth method to compute the depth of the buried geological body. Frist, we directly used the Theta map to estimate the depth of the source. Then we derived a linear equation based on the derivatives of Theta to compute the location and depth of the source. The presented method can use the Theta map as a constraint to obtain more accurate results effectively. The tests show that this Theta-Depth method can effectively calculate the location and depth of the source. We applied the Theta-Depth method to interpretation of measured magnetic data in the Mandula area, which helped delineate the distribution of ore veins.