14 January 2011

Friday fold(s): a few from Fossen

Posted by Callan Bentley

Last year, Haaken Fossen of the University of Bergen, Norway, published a full-color structural geology textbook called Structural Geology. So far, I think it is absolutely boffo. I’m reading it this semester as I teach structure at George Mason University, using my old standby text, George Davis and Stephen Reynolds’ Structural Geology of Rocks and Regions. I may switch to Fossen’s text next year. Certainly the imagery is enticing…

In exploring the online resources for the text, I was pleased to discover full-sized digital JPG files (600 dpi) for all the figures in the text. Nice! I was so taken with some of the fold images, that I e-mailed Dr. Fossen and asked him if I could feature a couple here as the “Friday fold.” He willingly granted me permission, and so I am pleased to present two eye-popping folds from his collection:

Folded banded iron formation with shale interbeds, exposed in a pavement near Soudan, Minnesota.

Buckled granitoid dikes within a gneiss from the Jotun Nappe, in the Norwegian Caledonides. The age of the folding is probably Grenvillian.

A full gallery of Fossen’s fold photos can be found at this link. If you click it, prepare to ooh and ahh for ten minutes or so.

Thanks to Dr. Fossen for permission to republish these images here.