Smooth Rock Surfaces and Streaks atop the Towers of Areu (Haute-Savoie, France): Tectonic or Snow-Glacial Genesis

Abstract

In the Haute-Savoie region of the French Pre-Alps, a meticulously designed experimental setup has yielded compelling evidence regarding the origins of polished and striated rocks found in a rather unanticipated context. Contrary to the initial hypothesis attributing these geological features to tectonic thrusting effects, typically manifested as fault mirrors exposed through erosion, the study reveals a different causative factor. It demonstrates that the annual movement of a firn, a type of perennial snowpack, is primarily responsible for the formation of these geological characteristics. This finding not only challenges conventional understandings in the field but also underscores the dynamic and often complex geological processes shaping the Earth’s surface.