Post on 24-Feb-2016
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Geology of the Headwaters of the Big Sandy River
from “The Virginia Headwaters of the Big Sandy River: A Story of Revitalization
and Nature’s Resilience”
Physiographic Province
• Appalachian Plateau Province or Cumberland Mountain Province
Age and Formation
• Estimated 250 million years old, formed during the Paleozoic era
• “Building” known as the Alleghenian Orogeny
Appalachian Plateau Province
• Relatively flat and historically stable
• Composed primarily of sedimentary layers
• Rugged due to dendritic erosion
Sandstone
• Clastic sedimentary rock• Tough and common• Sands deposited by seas
that once covered the area
• Responsible for many of the ridges in the area since it is hard to weather
Shale
• Clastic sedimentary rock formed from clay and silt deposits
• Fragile• Basis for much of the
bedrock faulting during orogeny
Limestone
• Sedimentary rock formed by shells and calcium carbonate
• Various uses: decrease damage of acid rain and risk of fires in mines
Karst Topography
• Created by groundwater that dissolves and erodes limestone beneath the surface
• Forms sinkholes, springs, caves, and streams that sink underground
Dolomite
• Sedimentary rock much like limestone, just higher in Magnesium
• Magnesium commonly extracted from it
• Used to make cement