27 August 2011

Friday fold addendum

Posted by Callan Bentley

Lee Allison, State Geologist of Arizona and exemplar of public outreach via blogging, sent me an e-mail yesterday regarding that awesome coastal Greenland shot by Alistair Knock that I featured as the Friday fold.

Lee, like many of you, found the image entrancing and intriguing, and as he explored the unannotated version, he made some discoveries. In this e-mail, Lee pointed out a few more faults that I hadn’t noticed. Here’s his annotation (red = bedding; green=faults):

By golly, I think he’s on to something there!

With such a beautiful, information-rich image, I had missed that particular detail. The middle of this antiform shows a nice little pop-up structure – like a horst, but inverted, bound by thrust faults rather than normal faults:

‘Tis the season for pop-ups, apparently. On Twitter the other day, Lockwood found one and called it a “splort” which I found to be an onomatopoetically apt moniker. I anno-tatted it up and sent it back at him, decreeing it a pop-up.

Anyhow, just wanted to share that with you. Did you see anything else in there that I might have missed?