27 October 2017

Friday fold: Quantankerous veins

Posted by Callan Bentley

What does it mean for a vein to be “quantankerous?” Well, to start with, it’s quartz. Second, it has to be disagreeable or cantankerous. This vein, seen in meta-arkose of the Catoctin Formation near the summit of the Blue Ridge at Rockfish Gap (not Afton Mountain), is such a quantankerous individual:

You’ll notice its “S” shape, which might imply top-to-the-left kinematics. But just down the outcrop is this set of folds:

They beg to differ, having assumed a “Z” shape, which might imply top-to-the-right kinematics.

One whispers, “Top to the left!” The other hisses back, “No! It’s top to the right, you fool!”

Who’s truthful? Who’s lying? We can’t tell based on the testimony of these unreliable witnesses.

Of course, asymmetric folds really can’t be trusted as kinematic indicators, so we should leave these quarrelsome veins to themselves. Let them bicker about the kinematics of the western Blue Ridge for eternity, for all I care.

It’s Friday. We have better things to do.

Enjoy the weekend!