In one of the former episodes of the ‘Features from the field’ series we have talked about foliations, and how they develop when rocks are pushed together by the movement of tectonic plates. It is quite uncommon, however, that tectonic forces are active in the same direction for an unlimited period of time. The rule, rather than the exception, is that the orientation of tectonic forces ...[Read More]
Features from the field: crenulation cleavage
Crenulation cleavage in schists from the Island of Elba (Italy). Note how the older foliation is folded and a new foliation developed. Photo © Samuele Papeschi