8 September 2017

Friday fold: Ptygmatic folding in gneiss

Posted by Callan Bentley

I was transferring some samples into my structural geology cabinet last week when I found this beautiful ptygmatic (“intestine-like”) folded quartz vein. I thought it deserved some wider circulation. I can’t recall where it came from, but it’s beautiful, with a train of a dozen or so isoclinal folds. So I made the digital media you see below. Enjoy!

Here’s a GIGAmacro of the sample (you need Flash enabled to view it):
Link 0.8 Gpx GIGAmacro by Callan Bentley

And here’s a 3D model of it: