Running head: Mining
GEO101 – Earth Science with Lab
Colorado State University – Global Campus
Dr. Shaji Nair
September 1, 2017
The Earth has long been the source of an abundance of resources, including the rocks and minerals on and below its surface. Civilizations have been mining minerals for ages and today, mining is a lucrative business worldwide. Near where I live in Washington DC, the mining of gold was prevalent.
More specifically, the state of Virginia was one of the first gold producing states in the nation. In 1782, Thomas Jefferson was the first to report the finding of gold-bearing rocks near the shores of the Rappahannock River (Sweet, 2007). In the early 1800s, gold in Virginia was extracted from deeply-weathered, near-surface lode deposits, and recovery was mechanically simple and labor was inexpensive (Sweet, 2007). Several years later, around 1825, gold mines started setting up shop along the Rappahannock River in search of the valued mineral.
One of the earliest mining facilities established in Virginia was Whitehall Mines and many mining mills followed. The most productive mine in the nation at that time was based in Virginia, producing $3,318,388 from 1929 through 1934 (Sweet, 1971). Mining continued in Virginia unabated until the start of the California Gold Rush in 1842, where many prospects started to migrate west. Production steadily slowed until the start of the Civil War, when production literally came to a screeching halt. Once the Civil War came to an end in 1865, many mines in the south were destroyed beyond repair. However, mines in Virginia were unscathed and continued production. Mining continued with minimal production until the start of World War II in 1941. Gold was last produced in Virginia in 1947 as a by-product of zinc and lead in Spotsylvania.
The gold mined in Virginia is typically found in Piedmont bedrock and thought to have been created during the time volcanic islands were formed in the Iapetus Ocean separate from the continental crust of Virginia (Gold in Virginia, n.d.). The gold formed in veins when Piedmont formed in the Appalachian, Taconic and Acadian orogenies. Triassic basins were created when the earth crust thinned. As faults moved, sediment in basins tilted and created cracks allowing molten basalt to move to the surface. With the pressure of the rock was released during earthquakes it is thought that other fluids also boiled up to the earth’s surface. When the silica finally cooled back into hard rock, quartz veins were formed. These quartz veins are where the gold deposits are now found. (Oskin, 2013).
So, what is gold? Gold is a very soft metal, rating a 2.5 on the Moh’s harness scale. The percentage of pureness is measured in carats, with 24 carat (24K) being the purest form of gold. Gold is manufactured in many percentages and form. While gold is naturally yellow, it is often blended can also be other metals to create alloys. Contingent on the...