Stylolites and mid-ocean ridges: development and similar dynamic system roughening

Mid-Ocean Ridges (MORs) and transform faults are a significant feature of the Earth’s surface that develop due to accretion of new material in an extensional regime. On a much smaller scale, stylolites are a dissolution feature in rocks that develop during compression and form distinct teeth structures. We present a comparison between the two features and argue that transform faults in MOR are similar to the sides of stylolite teeth with both features representing kinematic faults (KFs). First, we present a numerical model of stylolite and MOR growth and show that in both cases KFs nucleate and grow spontaneously. Secondly, we use Family-Vicsek scaling technique of describing fractal self-affine interfaces, which have been used for stylolites, to characterize the pattern of MOR systems. Our results show that both systems have self-affine scaling characteristics with similar scaling regimes. Both show a larger roughness exponent at small scales, a smaller exponent at the intermediate scale followed by a flattening of the system at the largest scale. For stylolites the physical forces behind the scaling are the surface energy (small scale), the elastic energy (intermediate scale) followed by the system reaching the correlation length where growth stops. For MORs the physical forces behind the scaling are not yet clear. However, the self-affine scaling shows that transform faults at MORs do have a fractal spacing, rather than a preferred spacing. Our study offers a new perspective on natural roughening phenomena on various scales and a new view on the development of MORs.