In Shenandoah National Park, astride Virginia’s Blue Ridge, feeder dikes of Catoctin Formation (meta-)basalt cut across the Grenvillian-aged granitoid basement. Due to their mafic composition and columnar jointing, these feeder dikes generally weather more rapidly than their host rocks. I led a field trip in the park on Thursday for my son’s school, and my student Marissa was there the weekend prior, checking out the autumn leaves and geology with her family. She and I have two new interactive media to share highlighting these dikes. I made a Theta 360° spherical photo of the feeder dike at Mary’s Rock Tunnel (south of Thornton Gap), and Marissa made a 3D model of the most prominent dike north of the Little Devil’s Stairs Overlook in the northern third of the park. Check them out:
~9 foot thick feeder dike of Catoctin Fm. meta-basalt cutting through Grenvillian basement in @shenandoahNPS Theta 360° Spherical Image by Callan Bentley