3 May 2019
Darrel Cowan of the University of Washington steps up today with another contributed Friday fold:
I made this photo when I took my class deep into Monarch Canyon in Death Valley NP this March. From work by Stanford and others, the rock is probably medium-to high-grade metamorphosed Pahrump Group, now a well-foliated gneiss. If we consider the foliation, here vertical [I’m looking directly down], the XZ-plane of bulk strain, the little dikelet or leucosome is folded where normal to the foliation, and stretched where oblique–just as predicted.
Perfect structural fodder to start your Friday morning off right! Thanks, Darrel – as always!