By: magic-gigapans
Image: Alan Pitts, Mid-Atlantic Geo-Image Collection
License: Creative Commons Non Commercial ⧉

Uploaded: 13 May 2020
Last Updated: 19 May 2020

1.43 gigapixels
43,924 x 32,464 pixels
146.4 in X 108.2 in at 300dpi
306 pixels per inch

This is an outcrop of brecciated quartzite located along the Shenendoah River near Ashby Gap Virginia. The quartzite is from the Cambrian Antietam formation, the upper most clastic unit of the Blue Ridge stratigraphic stack. The Antietam formation is interpreted as a beach/barrier island sand at the top of a transgressive sequence marking the break up of Rodinia. The brittle deformation of this rock is thought to have occured as a result of the westward thrusting and folding of the Blue Ridge province during Alleghenian mountain building. This Breccia occurs at the top of the Antietam formation near the contact with the overlying Tomstown Formation and could be local evidence of the larger Blue Ridge Thrust Fault system.