A novel method for the quantitative characterization of density distributions of elements in sedimentary geosystems is presented. This general technique is based on the multifractal analysis of image-processed elemental maps obtained by scanning electron microscopy combined with energy dispersive X ray spectrometry. Application to microdistributions of Si, Fe, and Al in recent bioactive siliciclastic marine sediments are reported. Inhomogeneous scaling behavior of these elemental distributions is observed in all cases. Two main conclusions can be drawn: (1) The sedimentary matrix exhibits true fractal geometry and (2) the processes allocating and rearranging the elements are not of pure stochastic type. Therefore the identification of genetic processes may be possible on the basis of their ''multifractal fingerprints.'' ¿ American Geophysical Union 1991