Research On Tilt Derivative And Application In Processing Gravity And Magnetic Data

The derivative of gravity and magnetic field expresses the speed of gravity and magnetic field's changing. It has extremely close relation with geological boundary. Therefore, methods using derivatives to find the boundary in the geological interpretation of gravity and magnetic plays a very important role. When there are some geological structure with different depth, as the conventional derivative of the anomaly caused by deeper geological structure is much smaller than the conventional derivative of the anomaly caused by geological structure, it is usually be ignored in the interpretation. Tilt derivative method solves this problem well. It is not sensitive to the depth of geological structure. So it can detect the boundary of structures with different depth successfully.Tilt derivative method is fist proposed by Miller and others in 1994.1n 2004, J. Derek Fairhead and others raised the concept of total level derivative of Tilt derivative. This paper first introduces the Tilt derivative method's background, the calculation of conventional derivative and the advantages and disadvantages are briefly introduced. Then establish some two-dimension gravity and magnetic models. The conventional derivative and Tilt derivative of the anomaly caused by the model are calculated. By comparison, the advantage of Tilt derivative is validated When there are some geological structure with different depth. Finally, take Tuquan basin gravity and magnetic date for example, the conventional derivatives and Tilt derivative are calculated. Then it comes the conclusion that Tilt derivative method is more effective than conventional derivatives in detecting the boundary of geological structure.