Shenandoah National Park: An Ecologic and Geologic Marvel
November 6, 2007
From the beaches of the Atlantic Ocean to the towering Blue Ridge Mountains, Virginia has a wealth of diverse landscapes that can suit almost anyone’s desire to see the great outdoors.
p. One of the most ecologically and geologically interesting places in Virginia rests within the boundaries of the Shenandoah National Park, situated in the Blue Ridge Mountains. The park is surrounded by the Shenandoah River and Valley to the west and the Virginia Piedmont to the east.
p. The Shenandoah National Park hosts a rich geological history, which explains the way the Appalachian Mountains formed.
According to the National Park Service, 1 to 1.2 billion years ago, tectonic plates collided to form the Grenville Mountain range in the area where the Appalachian Mountains now stand.
p. Around 570 million years ago, tectonic plates moved apart and lava began to flow, erupting at rift zones along the surface.
The lava flows that exuded from the rift zones formed the Catoctin Formation, creating broad, rolling plains similar to those found around Big Meadows in the Shenandoah National Park. The original lava flows were originally composed of basalt.
p. As they metamorphosed, they became richer in chlorite and epidote, and then became greenstones, which cap many peaks in the park. These greenstones produce jagged cliffs composed of very fine grains. The rocks tend to be of a light gray to rusted red color, but if freshly exposed, they appear green.
p. Sedimentary rocks in the park belong to a rock group known as the Chilhowee Group. This group is broken into three formations: the Weverton formation, composed of early river deposits; the Hampton formation, composed of lagoonal deposits; and the Erwin formation, which created beach sand.
p. The North American and African tectonic plates eventually collided with each other, fracturing the sea floor and causing the older metamorphic rock to tilt upward and slide under the younger sedimentary rock. This event created the Appalachian Mountains.
Over the past 250 million years, wind and water have eroded the Appalachian Mountains, transforming them from the jagged peaks of their initial original formation to the rounder peaks common today.
p. Whether you are interested in the complexity of the ecology and the geologic formations of the Appalachian Mountains or would prefer to simply hike or camp around them, the Shenandoah National Park offers a chance for everyone to explore the beauty and wonder of the Appalachian Mountains.