The other day while measuring joint orientation in the Weverton formation at Thoroughfare Gap, I stumbled upon this felsic vein down section in the Catoctin. We had already seen some minor faulting in the outcrops leading up to this one so it wasn’t a big surprise to find another one. From this angle it looks like the vein was offset laterally to the right, but when it is viewed from another angle the offset disappears. Just a case of tricky jointing.
Here is the vein looking offset…
…and here the offset is gone.
This could be a good lesson in seeing everything in 3D space, and “apparent” vs. “true”. Enjoy the video below as another example.