15 June 2012
Friday fold: home
Posted by Callan Bentley
Wow! Is it Friday already?
Time flies when you’re settling into your dream house. The Friday fold is of my new home, the doubly-plunging Massanutten Synclinorium:
The Alleghanian Orogeny is responsible for deforming these strata. Differential weathering produced the valley/mountain/valley pattern. The Cambro-Ordovician limestones and flysch (shale + graywacke) of the Martinsburg Formation in the Shenandoah and Page Valleys are susceptible to erosion, while the ridges of Massanutten Mountain are held up by a tough quartz sandstone (the Massanutten Sandstone, which is correlative to the Tuscarora Sandstone you’ll find further to the west in the Valley & Ridge). The land between the ridges is another valley, the Fort Valley, which is again etched away due to low resistance to the forces of erosion: it’s more limestone, more shale, and some siltstone and bentonite thrown in, too. That’s where I live: at the horizon where the top of the Massanutten Sandstone meets the overlying Helderberg Group carbonates.
Our first few days “up in the Fort” have been spectacular. We’ve seen many birds from our front porch, and been blessed with cool mountain weather. It’s a great place to be. Enjoy your weekend.