Fractal and genetic aspects of Khuff reservoir stylolites, Eastern Saudi Arabia

Stylolites from the Saudi Arabian Permian Khuff formation are characterized by a fine-grained, dark-colored, more-or-less fabric-oriented and insoluble seam material. The seams are three-dimensional; however, in the present study, only their visible cross-sectional aspects are considered for geometrical classification and fractal analysis. Detailed thin-section, SEM, and XRD studies were conducted on stylolite-bearing Khuff carbonates to determine their mineralogy and fabric. Twenty-two stylolite seams were also subjected to fractal analysis. For every stylolite we characterized its fractal nature by means of the Hausdorff-Besicovitch dimension D_HB and its self-affinity in the direction perpendicular to the seam's axis by means of its Hurst exponent H. The HB-dimensions ranged between 1-1.3, the Hurst exponent between 0.2-0.75, and we found that stylolites belonging to different geometrical classes plot into distinct clusters on the D_HB versus H crossplot.