Automatic conversion of magnetic data to depth, dip, and susceptibility contrast using the SPI (TM) method

The Source Parameter Imaging (SPI™) method computes source parameters 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 independent of the magnetic inclination, declination, dip, strike and any remanent magnetization; however, the dip and the susceptibility estimates do assume that there is no remanent magnetization. Image processing of the source‐parameter grids enhances detail and provides maps that facilitate interpretation by nonspecialists. The SPI method tests successfully on synthetic profile and gridded data. SPI maps derived from aeromagnetic data acquired over the Peace River Arch area of northwestern Canada correlate well with known basement structure and furthermore show that the Ksituan Magmatic Arc can be divided into several susceptibility subdomains.

[1]  L. J. Peters.  The Direct Approach to Magnetic Interpretation and its Practical Application , 1949 .

[2]  D. Cant.  Regional Structure and Development of the Peace River Arch, Alberta: A Paleozoic Failed-Rift System? , 1988 .

[3]  H. V. Ram Babu,et al.  Interpretation of magnetic anomalies due to dikes: The complex gradient method , 1981 .

[4]  R. Bracewell.  The Fourier Transform and Its Applications , 1966 .

[5]  S. Bowring,et al.  Geophysics and geochronology of the crystalline basement of the Alberta Basin, western Canada , 1991 .

[6]  I. W. Somerton,et al.  Magnetic interpretation in three dimensions using Euler deconvolution , 1990 .

[7]  Misac N. Nabighian,et al.  The analytic signal of two-dimensional magnetic bodies with polygonal cross-section; its properties and use for automated anomaly interpretation , 1972 .

[8]  M. Reford.  MAGNETIC ANOMALIES OVER THIN SHEETS , 1964 .

[9]  C. Zelt,et al.  Seismic structure of the crust and upper mantle in the Peace River Arch Region, Canada , 1989 .

[10]  R. J. Brown,et al.  Automated source‐edge location with a new variable pass‐band horizontal‐gradient operator , 1994 .

[11]  H. Naudy.  AUTOMATIC DETERMINATION OF DEPTH ON AEROMAGNETIC PROFILES , 1971 .

[12]  V. Baranov.  A NEW METHOD FOR INTERPRETATION OF AEROMAGNETIC MAPS: PSEUDO‐GRAVIMETRIC ANOMALIES , 1957 .

[13]  Walter R. Roest,et al.  Magnetic interpretation using the 3-D analytic signal , 1992 .

[14]  D. T. Thompson,et al.  EULDPH: A new technique for making computer-assisted depth estimates from magnetic data , 1982 .

[15]  S. K. Runcorn,et al.  Interpretation theory in applied geophysics , 1965 .

[16]  D. Teskey,et al.  A system for rapid digital aeromagnetic interpretation , 1970 .

[17]  M. Taner,et al.  Complex seismic trace analysis , 1979 .

[18]  S. Hsu,et al.  High‐resolution detection of geologic boundaries from potential‐field anomalies: An enhanced analytic signal technique , 1996 .

[19]  Sudhir R. Jain.  An automatic method of direct interpretation of magnetic profiles , 1976 .