AUTOMATIC CONVERSION OF MAGNETIC DATA TO DEPTH, DIP, AND SUSCEPTIBILITY CONTRAST USING THE SPI (TM) METHOD

The Source Parameter Imaging (SpI(TM)) method computes source paramete rs from gridded magnetic data. The method assumes either a 2-D sloping contact or a 2-D dipping thin-sheet model and is based on the complex analytic signal. Solution grids show the edge locations, depths, dips , and susceptibility contrasts. The estimate of the depth is independe nt of the magnetic inclination, declination, dip, strike and any reman ent magnetization; however, the dip and the susceptibility estimates d o assume that there is no remanent magnetization. Image processing of the source-parameter grids enhances detail and provides maps that faci litate interpretation by nonspecialists. The SPI method tests successf ully on synthetic profile and gridded data. SPI maps derived from aero magnetic data acquired over the Peace River Arch area of northwestern Canada correlate well with known basement structure and furthermore sh ow that the Ksituan Magmatic Are can be divided into several susceptib ility subdomains.