A fold is visible in a mountainside consisting of layered basalt lava flows. A truck drives down the highway in the foreground

A large chunk of petrified wood sits on the ground. In the background a chain fence marks the edge of a cliff dropping off to a wide river below.

Some #FridayFolds and #FridayFossils on the last day of fall quarter classes. Managed to have a nice field trip this afternoon despite getting our rental vans three hours late! ⚒️

Slowly coming back to me! More #FridayFolds there with Andy Bell for scale

Banded black, grey and white gneiss shows minor S shaped folds in sheared Lewisian gneiss. Berneray, Outer Hebrides.

Live from the field, #FridayFolds on Berneray, Outer Hebrides.
Sheared Lewian gneiss.
Waiting for tide to go out 😎

Banded grey Lewisian gneiss with some thicker layers of white or pink granitic pegmatite and black amphibolite show complex folding. In some cases the folds are affected by shearing. The outcrop is well exposed and clean, having been wave washed to keep it clear of surface algae/shellfish/seaweed. The compass-clinometer scale is 15cm long.

There are many larger folds in the #Lewisian gneisses around Cunndal Bay, #IsleofLewis, but these #FridayFolds are the best exposed, (cleanest) I've seen, so far.
⚒️🧪 #Geology

And some more #FridayFolds from #Donegal

Back up in #Donegal at #SliabhLiag doing a bit of geology teaching and discovery. Just look at these #FridayFolds and the cleavage. No idea what the black layer is BTW, Dalradian quartzites in the area...