SCALING BEHAVIOR OF VERTICAL MAGNETIC-SUSCEPTIBILITY AND ITS FRACTAL CHARACTERIZATION - AN EXAMPLE FROM THE GERMAN CONTINENTAL DEEP DRILLING PROJECT (KTB)

The variations of rock magnetism reflect the geological inhomogeneitie s of the earth's crust, i.e. its petrological-mineralogical and struct ural organization. The present state of the crust bears meaningful inf ormation of its past dynamic processes and evolution. We analysed magn etic susceptibility data series from the boreholes of the German Conti nental Deep Drilling Project (KTB). By means of spectral and rescaled- range (R/S) analyses we could detect a scaling behav lour of magnetic data series and quantify it in fractal terms. In particular, the RIS m ethod yields more precise results than the Fourier analysis and leads to Hurst coefficients H > 0.5, which means that the magnetic variation s exhibit some persistence with depth. Because of the relation between rock magnetism and crustal features, we suggest that the magnetic ver tical inhomogeneities in the KTB area can be described by a self-affin e model with H congruent to 0.8, corresponding to a fractal dimension D congruent to 1.2.