5 March 2014

Oriskany Formation quartz arenite and its fossils, Corridor H

Posted by Callan Bentley

Today, a few more photos from the field trip last month to Corridor H, the fine new superhighway with so little traffic out in eastern West Virginia.

Our antepenultimate stop of the day was at an outcrop we inferred should hold the Oriskany Sandstone, a Devonian quartz arenite that lies stratigraphically above the Helderberg Group limestones and below the Needmore Shale. We were using Lynn Fichter’s indispensible stratigraphic column for our explorations, and while some of the Oriskany looked like what I expected it to, there was also a greater diversity of the unit than we expected: dark gray color in places (rather than the sugary white I recalled as classic Oriskany), conglomerates, etc.

We did find a bunch of brachiopod fossils, though, and that is something I associate with outcrops of the Oriskany such as those on Sandy Mile Road near Sideling Hill. Let’s see some…

Articulate brachiopod shells in cross-section:


Here’s another brachipod, a huge one with a relatively flat morphology, a strophomenid, I reckon:


Zoom in on the fine radiating costae on the shell:


I pried off some of the overlying sandstone to reveal more of this lovely beast:


And, just for variety’s sake, here’s a gastropod (snail) we found at the site, too: