On Tuesday afternoon, four students and I drove from Annandale, VA, up to Buffalo, NY, for the NE section meeting of the Geological Society of America. On the way, we crossed the Pennsylvanian Appalachians, and pulled over to examine some beautiful redbed exposures on the Pennsylvania Turnpike. I think these are in the Hampshire Formation, but I could easily be wrong about that, considering I've never been here before. Here's a few photos. First, some beautifully rhythmic alternations between sand and mud, now preserved as alternating layers of sandstone and mudstone:

Then, some nice "ball and pillow" structures, as heavy sand sank downward into squishy mud. In places, the mud skooshes upward in "flames":

And lastly and most amazingly (for me), some awesome exposures of flute casts. These are erosional scours into a layer of sediment by a current, which then fills in the scours (called "flutes") with sand, making these flute casts on the underside of the overlying layer of sand:

The flutes "point" upstream, and open up (and shallow) in the downstream direction. More later!

Labels: appalachians, meetings, nova, pennsylvania, primary structures, sediment, teaching