13 February 2015

Friday fold: Ptygmatic Irving Fm., Colorado

Posted by Callan Bentley

Another one from Kim:


Kim says:

Pygmatic folds in the Precambrian Irving Formation. I think this is 1.7 Ga deformation, late in the Yavapai orogeny, which added various arcs in Colorado to North America. Good place to think about strain ellipses in progressive deformation.

Zooming in on the best part, and dialing up the contrast a bit:


That’s intense!

Seriously strained rocks. What fun!