Interstate 64 from Lexington, VA to Charleston, WV is one of the most stunning routes in the eastern US from a geological standpoint. Immediately after crossing the state line into West Virginia you can see this rock exposure (above) on the south side of the highway, with sedimentary rock layers tilted about 70 degrees from horizontal. The surfaces of some of these layers are covered with ripple marks, visible from across the highway:
As you continue west on I-64, the road cuts across the Appalachians and eventually begins to follow the Kanawha River valley towards Charleston (the New River in Virginia is a tributary of the Kanawha). This leads you through a series of spectacular, towering roadcuts, that were mostly hidden from us on Wednesday due to snow. But every now and then the weather would clear enough to see things like this:
These are classic Pennsylvanian Period coal and sandstone deposits. The dark coal beds are formed from highly compressed fossil plants that were probably living in the flood plains or deltas of rivers. The light-colored sandstones most likely represent deposits within the river channels as they migrated back and forth across the flood plain. The curves in the beds could be a result of the shape of the channel, tectonic deformation from the formation of the Appalachian Mountains (which occurred after these rocks were deposited), different amounts of compression in the various rocks, or all three of these things.
After passing through West Virginia, I-64 takes you through more flat-lying and much older Ordovician Period sedimentary rocks. Once again, the winter weather obscured much of the geology: