13 September 2019

Friday fold: crinkled schist from Italy

Posted by Callan Bentley

AGU’s Chief Digital Officer Jay Brodsky offers up a fresh European fold for you today — and this one is on rather a smaller scale than Jay’s last Friday fold contribution

Click through for a bigger version.

These are lovely crinkly folds in highly foliated rocks. I love boxy little crenulations like these.

Jay tells me that this is from

Graines, Italy, in one of the valleys of the Val D’Aosta right by this castle.

Jay asked “What is it?” and I replied that “it looks metamorphic.” But I also made an attempt at digging deeper:

I brought up a geologic map of Italy, and draped it onto Google Earth, lining up major cities and Milan to get it positioned correctly, and then put the Castle of Graines into the search button:

… So that is this spot, and the rock type there appears to be rock type 99, “medium grade metamorphic rocks:”

Well, that doesn’t tell us too much, but these appear to be metamorphic rocks (‘scisti!’) that enjoyed deformation during Alpine mountain-building.

As always – if anyone else recognizes these lovely folds, or knows any greater detail about the geology of this region, chime in via the comments below.

Thanks — and Happy Friday!