4 April 2012
From the Brallier Formation at the furthest end of Corridor H (What we like to call “the new New 55”) in north-central West Virginia, there is a wealth of folded and faulted shale. When the individual layers of sedimentary rock crumpled, they slid over one another, so that the bedding plane itself became reactivated as a sort of “fault” surface. Accordingly, the tops and bottoms of the beds developed some features that we traditionally associate with faults, such as slickenlines and fault polish.
The shiny polished surface is best appreciated when viewed from a variety of different orientations: