The roughness of stylolites: Implications of 3D high resolution topography measurements

TL;DR

This study provides high-resolution 3D measurements of stylolite roughness, revealing scale-dependent self-affine properties and a crossover length, with implications for understanding their formation processes.

Contribution

It introduces detailed 3D topography measurements of stylolites and models their growth using a Langevin equation considering elastic interactions and material disorder.

Findings

Stylolites exhibit scale-dependent self-affine roughness.

A crossover length scale of approximately 1 mm separates different roughness regimes.

The growth process is consistent with a Langevin equation involving elastic interactions and quenched disorder.

Abstract

Stylolites are natural pressure-dissolution surfaces in sedimentary rocks. We present 3D high resolution measurements at laboratory scales of their complex roughness. The topography is shown to be described by a self-affine scaling invariance. At large scales, the Hurst exponent is $\zeta_1 \approx 0.5$ and very different from that at small scales where $\zeta_2 \approx 1.2$. A cross-over length scale at around $\L_c =1$~mm is well characterized. Measurements are consistent with a Langevin equation that describes the growth of a stylolitic interface as a competition between stabilizing long range elastic interactions at large scales or local surface tension effects at small scales and a destabilizing quenched material disorder.