3. This perched boulder currently resides on to of an outcrop of Catoctin Formation greenstone (metamorphosed basalt). At the parkway's  Greenstone Overlook. The greenstone's tint is due to the presence of the mineral chlorite.
1. The parkway's many scenic turnoffs provide the best overall perspective of the Blue Ridge Province of the Appalachian Highlands Region. This belt of forest-clad mountains is upheld by metamorphic rocks approximately one billion years old. Note the landslide scar on a distant ridge, which is much more visible in the larger version of this photo.
GEORGE WASHINGTON NATIONAL FOREST
(VARIOUS NORTHWESTERN COUNTIES)
LEE COUNTY


Raymond Wiggers
Gallery: Virginia Geology

- Last Updated 12 June 2009 -
IMPORTANT NOTICE: All photos are copyrighted by Raymond Wiggers. If you are an educator or student and would to like to use any of these images, e-mail me and let me know how the images will be used. Please also credit me as the photographer. I ask that all companies, organizations, and government agencies contact me about my fees for the use of my photos, and about obtaining higher-quality versions on CD-ROM. Thanks for your understanding and compliance with the law.


To go directly to a particular state represented in this gallery, click on its name below:

- Blue Ridge Parkway (various western counties)

- George Washington National Forest (various northwestern counties)

- Lee County

- Lynchburg & Vicinity (Bedford & Campbell Counties)

- Natural Bridge (Rockbridge County)

- Natural Tunnel State Park (Scott County)

- Shenandoah National Park

8. West of Lynchburg, along the western side of Route 501, is this low outcrop  of the Moneta Gneiss, a high-grade metamorphic rock that has been subjected to great heat and pressure. This is the Piedmont, a zone of low hills that lies to the east of the Blue Ridge. Like the Blue Ridge, this province is underlain by ancient rocks of the Upper Proterozoic Eon.
9. Farther north, along Route 501 just above Boonsboro, lies this revealing cut into the old, iron-rich soil made of saprolite -- the highly weather residuum of the underlying metamorphic rocks.
6. Not far from the preceding roadcut and also along Route 501 stands this exposure of highly weathered phyllite and gneiss if the Upper Proterozoic Pedlar Formation. The phyl-lite (the upper half of the exposure) apparently represents a paleosol, or ancient soil subsequently turned to stone. This soil formed at a time when neither  plants nor animals had yet colonized the land.

BLUE RIDGE PARKWAY
(VARIOUS WESTERN COUNTIES)
LYNCHBURG & VICINITY
(BEDFORD & CAMPBELL COUNTIES)
NATURAL BRIDGE (ROCKBRIDGE COUNTY)
NATURAL TUNNEL STATE PARK (SCOTT COUNTY)
SHENANDOAH NATIONAL PARK
2. An exposure of charnockite, a granitelike rock, along the parkway south of the Tye River Gap. In this locale, this igneous intrusive outcrop has a bluish tint due to the presence of microcline crystals.
4. A roadcut of sandstone of the Lower Cambrian Chilhowee Group, along Route 501 in Amherst County. This locality has excellent examples of anticlinal (bowed upward) and synclinal (bowed downward) folds, which demostrate the powerful compressional forces at work some 300 million years ago, when northwestern Africa collided with North America to form the supercontinent of Pangea.
5. A closer look at a small anticline, at the same outcrop. Behind the observer lies  the James River, which has cut an impressive valley through the highly resistant rocks of Virginia's Blue Ridge and Piedmont Provinces.
7. To the west of the Blue Ridge lies the  beautiful Ridge and Valley Province -- a land of bucolic lowlands separated by high, linear mountains composed of sedimentary rocks of the Paleozoic Era. This is the view along Route 58, about 10 kilometers (6 miles)  east of the Cumberland Gap.
12. Another karst landmark in the Ridge and Valley Province, and this time one held in the public trust. Here, one must  descend, either by foot or by this particularly precipitous chair lift, into a sinkhole to see the naturally formed tunnel.

13. The limestone walls of the collapse chamber leading to the tunnel show signs of substantial chemical weathering. This carbonate sedimentary rock belongs to the Cambrian- and Ordovician-aged Knox Group.
14. The Southern Portal of the Natural Tunnel. Note the train tracks, still very much use. This cavity was formed by the dissolution of  weakened rock along the Glenita Fault.
15. A look at the Glenita Fault itself, just outside the South Portal. Note how the lower strata visible here have been deformed by the movement along the fault plane.
16. Another example of deformation in the footwall, or lower block, of the Glenita Fault -- this time, just inside the tunnel.
17. At the Rockytop Overlook along the park's Skyline Drive --
in effect the northern continuation of the Blue Ridge Parkway. This roadcut exposes  metaquartzite (metamorphosed sandstone) of the Cambrian Period Erwin Formation.
18. A ledge of the Cambrian-aged Hampton Formation phyllite and quartzite along the park's section of the Appalachian Trail, just south of the Doyles River Overlook.
11. Looking straight up at the Natural Bridge's ceiling. This limestone, part of the sedimentary sequences that make up the Ridge and Valley Province, precipitated at the bottom of a shallow sea in Cambrian time, a little more than 500 million years ago -- 200 million years before continental collision formed the lofty mountains of the Alleghenian Orogeny. The bridge probably formed by the collapse of a long, narrow cavern segments. Other intact caverns, characteristic of the solution-formed topography known as karst, are found nearby.
10. In the town of Natural Bridge stands the wonder that is its namesake. Described by Thomas Jefferson, who once owned this land -- as "the most sublime of Nature's works," this impressive span demonstrates the power of mildly acidic water to dissolve hard limestone. While it's regret-table that this famous landmark is now a highly com-mercialized attraction rather than a state park, it remains an essential venue for the geologically inquisitive.