Geology
The High Knob Landform of Stone Mountain forms one of the greatest natural areas in the eastern United States. Today its calcareous heart has been breached by massive erosion to expose an ecologically renowned karst landscape which stretches from the Powell Valley area of Wise County, southwest across the Powell River Valley of Lee County to the Norris Lake of Tennessee. Drainage from High Knob has also formed hydrologically complex conduit systems which have directly led to formation of the magnificent Natural Tunnel and Rye Cove Karst Basin of Scott County, where endemic species such as the Rye Cove Isopod are found.
Features
In the area around the High Knob Landform, High Knob(southeast of Grindstone Ridge) is dominant structural feature of the Powell Valley Anticline of the Cumberland Mountain Overthrust Block. With its adjoining faults (Hunter Valley-Clinchport system), this region possesses the greatest concentration of significant caves in Virginia.
The summit of High Knob in particular exerts a significant impact upon the climate of southwestern Virginia and surrounding areas, being one of the rainiest and snowiest locations in both Virginia and the southern Appalachians.
This orographically forced climate has, through the vastness of time, worked in intimate union with the geology and topography to create a richly diverse landscape possessing vast biological diversity.
High Knob unofficially holds the record for the most snow ever measured in Virginia during a single season, with 200.5 inches (509 cm) during the 1995–96 winter.
During a typical year, 60.0 inches to 70.0 inches (152.4 cm to 178.0 cm) of total precipitation falls across the area, to make it one of the wettest areas north of the Great Smokies, and the wettest in Virginia for which there are available records. Significant additional moisture contributions occur from fog drip off trees and rime deposition on trees, with many days during the year being spent amid orographic feeder clouds that cap its upper elevations.
About the valley
The valley begins between Powell Mountain and Little Stone Mountain where the waters of the Powell River Flow down from the rugged mountains of western Wise County.
The immense exposed rock face where Stone Mountain and Powell Mountain come together near Grindstone Ridge to the southeast from the overlook, yields a striking visual change in altitude. Within only 0.8 mile the vertical elevation changes by 2,000 feet ( 610 meters ) across the northern face of the Grindstone Ridge Dome of the High Knob Massif, to mark one of the greatest short-distance vertical elevation changes in the southern Appalachians (the greatest found west of the Blue Ridge in Virginia).
The valley follows the Powell River west towards the Tennessee border.
Majestic Powell Valley is part of the High Knob Landform, lying literally amid its heart and eroded core, and is a true geologic wonder.
How it got it's name!
The Virginia longhunter, explorer and later Revolutionary War general Joseph Martin was instrumental in opening up Powell Valley to settlement from the east.
Beginning in 1774, Chief Benge led a part of the Shawnee from the Ohio River on Raids along the frontier. Chief Benge, who was part white and part Cherokee, frequently captured slaves and then resold them; he also seized white women and children who were then adopted by various Indian groups. On 6 April 1794, Chief Benge attacked the Henry and Peter Livingston farm on the Holston River and took several residents prisoner, and marched them northeast. Three days later, when they entered the Powell Mountain Gap just north, Lt Vincent Hobbs and eleven Lee County militiamen ambushed them, killing Chief Benge with a murderous volley of musket fire, and freed the captives.
To get credit for the find, please email me the answers to the following questions.
1. What landform is Powell Valley part of?
2. Looking at the ridge across from the viewing area(Grindstone Ridge), what are the colors of exposed rocks?
3. From the viewing deck, estimate the distance to Grindstone Ridge .
You are welcome to post photos of your visit to the site, but this is optional and not part of the logging requirements.
Thanks and enjoy!
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