Oblique view (to the north-northeast) shaded relief map of the Valley & Ridge province near Blacksburg, Virginia.
Oblique view of the Valley & Ridge
Author Archives: cmbail
Virginia is for Lavas- The Catoctin Formation
Columnar joints in metabasalt of the Catoctin Formation exposed along the Skyline Drive, in Shenandoah National Park.
Many of the highest peaks in Shenandoah National Park (including Hawksbill, Stony Man, and Hightop Mountain, just to name a few) are underlain by distinctive bluish-green rocks that were once ancient lava flows (Virginia is for Lavas!), and are part of a geologic unit known as the Catoctin Formation. From the presidential retreat at Camp David to Jefferson’s Monticello, from Harpers Ferry to Humpback Rocks, the Catoctin Formation underlies much of the Blue Ridge. This distinctive geologic unit tells us much about the long geologic history of the Blue Ridge and central Appalachians. Click here for the complete story of the Catoctin Formation.
Mouth of the Rappahannock River
Aerial view (to the southeast) towards the mouth of the Rappahannock River. Photo by C. M. Bailey
The Rappahannock River forms a broad estuary as it flows to towards the Chesapeake Bay in Virginia’s Coastal Plain province. To the south the Piankatank River is also visible. The Rappahannock and Piankatank rivers are tidal estuaries.
Cliffs of Westmoreland
The Cliffs of Westmoreland rising above the Potomac River on Virginia’s Northern Neck. photo by C. M. Bailey
The Cliffs of Westmoreland rise 30 to 45 meters (~100 to 150′) above the waters of the Potomac River. These bluffs expose Miocene to Pliocene sedimentary units, some which are quite fossiliferous. For more information on the geology of Westmoreland checkout the 2005 Virginia Geological Field Conference guidebook by Buck Ward and others. Note the erosion-control structures along the shore (lower right).
Nottoway Falls
Nottoway Falls in the Piedmont of south-central Virginia. photo by C. M. Bailey
Nottoway Falls is an impressive set of cascades along the Nottoway River in the south-central Piedmont. Here the Nottoway River forms an impressive knick zone, dropping ~30 meters (~100′) in less than 1 kilometer (0.6 mi.). A strongly lineated granitic gneiss is well-exposed during low water conditions. The origin of this knick zone is poorly understood.