Gold in Virginia

gold forms in Type II supernova explosions, such as the one that formed the Crab Nebula
gold forms in Type II supernova explosions, such as the one that formed the Crab Nebula
Source: NASA Goddard Space Flight Center, Flickr

Gold found in Virginia today was formed originally by the collision of two neutron stars or when the nickel-iron core collapsed in a Type II supernova. All elements in the universe with more than 26 protons in their nucleus (i.e, "heavier" than iron) were created through neutro capture processes. Protons in the nuclei capture electrons and become a neutron, followed by beta decay where some of the neutrons emit an electron and a neutrino to evolve into new protons. The nucleosynthesis of gold occurs very quickly in what physists called the r-process. Those heavier-than-iron elements were then disseminated into space via cataclysmic events, and then accumulated via gravitational forces into asteroids and ultimately planets.

The gold on earth may have been created by the collision between two neutron stars 80 million years before the formation of our solar system. A neutron star merger within 1,000 light-years of our solar system could have created a high percentage of the heavy elements that coalesced and formed the planets.1

Over the last 4.6 billion years, gold molecules have moved within the mantle and crust. The gold found in Virginia today can be traced back to the time volcanic islands formed in the Iapetus Ocean, before they were accreted to the continental crust and created the supercontinent of Pangea.

In the formation of Pangea, subduction of crust led to melting and differentiation of different minerals within the magma. The gold in what today is Piedmont bedrock separated originally from other minerals in the magma "melt" between the Taconic and Allehenian orogenies, roughly 400-200 million years ago. As the mass of molten rock slowly cooled below 1,943°F, gold molecules shifted from a liquid to a solid state and "froze" or crystallized in place.

Most of the molten gold crystallized within bedrock while still buried miles underground. Some vaporized gold could have been emitted from volcanoes as fine particles with volcanic ash, and formed placer deposits on the surface of the island or on the Iapetus Ocean seafloor nearby.

Most likely, all the Virginia gold was remelted and moved (remobilized) during the Taconic, Neo-Acadian, and Alleghanian orogenies. Under heat and pressure, the gold originally contained within volcanic islands was squeezed along with silica (quartz) into the veins now scattered within the metamorphosed bedrock of the Virginia Piedmont.

Some veins may be even younger than the Alleghanian orogeny, and date from the time when Pangea split up about 225 million years ago. Triassic basins developed when the crust thinned. Earthquakes were a common occurrence as blocks of crust moved at faults moved. The sediments in the basins tilted and molten basalt at great depth jetted through cracks to the surface. When the pressure of the overlying rock was released briefly during earthquakes, other fluids may also have boiled up towards the surface. When silica cooled back into hard rock, it formed new quartz veins - and in those locations where gold had been a component of the molten fluids at depth, those quartz veins included gold deposits.2

The earliest English settlers of the Virginia Company were looking for gold. Gold equals wealth, at least to humans. The richest man in the history of the world was been the ruler of Mali, Mansa Musa. In the early 1300's, he controlled more wealth than any other human who has ever lived because Mali produced most of Africa's gold. It was the major source of gold for Europe until the discovery of the New World.3

control of gold made Mansa Musa, ruler of Mali, the richest human in the world
control of gold made Mansa Musa, ruler of Mali, the richest human in the world
Source: Wikipedia, Catalan Atlas

The Spanish seized vast amounts of gold from Aztec, Inca, and other Native American societies in Central and South America. The English started their colonization efforts about a century later, and targeted North America to avoid conflict with existing Spanish settlements. In Virginia and then later colonies, the English did not discover any native societies in North America that had mined and accumulated gold. The gold discovered by the English within Native American communities along the East Coast had been acquired from shipwrecks or exchange with early Spanish and French settlers.

The first gold rush in the United States occurred in North Carolina, nearly two centuries after Jamestown was settled. In 1799, a 12-year old boy found a heavy rock with a yellow color near the site of modern Charlotte. The family used it as a doorstop until 1802, when a North Carolina jeweler bought the rock for $3.50. After he revealed the doorstop was a 17 pound gold nugget, the gold rush began in the western North Carolina Piedmont. Initial mining depleted placer deposits, where gold had accumulated in streambeds. In 1825, miners began digging in the ground to extract gold from lode deposits, where it was mixed with quartz in veins.4

Thomas Jefferson documented the first gold discovered within Virginia:5

I knew a single instance of gold found in this state. It was interspersed in small specks through a lump of ore, of about four pounds weight, which yielded seventeen penny-weight of gold, of extraordinary ductility. This ore was found on the North side of Rappahanock, about four miles below the falls. I never heard of any other indication of gold in its neighbourhood.

That lump of ore would have washed down from its original location in the Piedmont, past the Fall Line at Fredericksburg, before settling with other sediments in a placer deposit on the Coastal Plain. Jefferson's handwritten version of Notes on the State of Virginia suggests he had heard of gold in the Piedmont physiographic province, but he edited out that information about Gold Mine Creek before publication.6

Thomas Jefferson may have been aware of gold in Louisa County, as well as a nugget found downstream of Fredericksburg
Thomas Jefferson may have been aware of gold in Louisa County, as well as a nugget found downstream of Fredericksburg
Source: Massachusetts Historical Society, Notes on the State of Virginia (p.14)

Gold Mine Creek now flows into Lake Anna
Gold Mine Creek now flows into Lake Anna
Source: ESRI, ArcGIS Online

Gold was brought to Virginia by colonists, but coins of gold and silver were scarce. There was so little "hard" money that Virginians used tobacco receipts as a form of cash.

the Chesapeake and Ohio Railroad identified where gold might be mined along its route in the Piedmont
the Chesapeake and Ohio Railroad identified where gold might be mined along its route in the Piedmont
Source: Library of Congress, Map showing the economic minerals along the route of the Chesapeake & Ohio Rail Way (Thomas S. Ridgway, 1872)

Various legends claim that General Braddock brought a paychest filled with gold in 1755 to Alexandria, before he marched to capture Fort Duquesne from the French. In one legend, the gold was buried along what is known today as Braddock Road near Centreville in Fairfax County, before Braddock's military operation got far from Alexandria on its way to disastrous defeat in Pennsylvania. The coins intended to be used for paying the soldiers were melted and poured into cannon barrels, then buried to lighted the load and prevent wagons from getting stuck in the mud.

Other legends suggest the gold was buried during the hurried return after the defeat on the Monongahela River. To date, treasure hunters have found nothing, while historians debunk the claims.7

Lake Anna State Park highlights the history of the Goodwin Gold Mine. Interpretive panels note that the first gold mine in the state was funded by New York investors in 1832, and 170 operated in the gold-pyrite belt. Between 1830-1850, Virginia was the third-largest gold-producing state.

The Goodwin Mine site was identified after placer mining revealed the site. In placer mining, the heavy gold flakes within stream sediments were separated from quartz sand and clay particle by panning, then by the use of sluices. To reach the ore, the source of the gold flakes, Baltimore investors funded the excavation of a shaft in 1881. The shaft eventually was 95 feet deep.

The gold was mixed with quartz in the ore-bearing rock removed from the mine. That ore was crushed to fine particles, and mixed with mercular. The gold amalgamated with the mercury. THe combined gold and mercury was then separated and heated. THe mercury boiled off, leaving the gold behind. By cooling the vapors, the mercury could also be recovered and reused.8

All commercial gold mines in Virginia were closed during World War II, after the Federal government determined that the mining was non-essential and resources (including labor) needed to be directed towards military support. The price of gold had been fixed by the Federal government at $35/ounce, and after World War II the cost of mining in the post-war economic boom exceeded the $35 threshold. Commercial gold mining never got restarted.

In 2014, the Board of County Supervisors in Goochland County approved a proposal to re-open the Moss Mine, which had operated intermittently between 1835-1939. Constant flooding by groundwater had limited the ability to excavate the gold ore through shafts.

The new proposal was to develop an open pit mine the size of a football field, following a 2-wide gold vein down to 125 feet in depth. Gold would be obtained by "free milling," using water and gravity to physically separate the gold from worthless quartz and other materials without use of cyanide, mercury, or other chemicals. The applicant described the project as a mine clean-up project, and even suggested he might obtain government funding for site reclamation. The soil was contaminated with mercury, which had been used in the past to separate out the gold particles.

Extracting the gold was expected to take just three years. Afterwards, the waste rock would be replaced in the pit, the site would be reclaimed, and a wetland created. The projected $2 million cost for mining might be offset by the gold that would be extracted, but at a minimum the property would be more marketable after removal of the mercury.9

in 2014, Goochland County officials approved re-opening the historic Moss Mine (red X) for gold mining
in 2014, Goochland County officials approved re-opening the historic Moss Mine (red X) for gold mining
Source: ESRI, ArcGIS Online

Links

References

1. John Cowan, Friedrich-Karl Thielemann, "R-Process Nucleosynthesis in Supernovae," Physics Today, Volume 57, Issue 10 (October 1, 2004), http://doi.org/10.1063/1.1825268; "Scientists Think They've Found the Ancient Neutron Star Crash That Showered Our Solar System in Gold," Live Science, May 6, 2019, https://www.livescience.com/65411-neutron-star-collision-rains-bling-on-solar-system.html; Imre Bartos, Szabolcs Marka, "A nearby neutron-star merger explains the actinide abundances in the early Solar System," Nature, Volume 569 (May 1, 2019), https://www.nature.com/articles/s41586-019-1113-7 (last checked May 8, 2019)
2. "Earthquakes Turn Water Into Gold," LiveScience, March 17, 2013, http://www.livescience.com/27953-earthquakes-make-gold.html; "The Big Smelt," Rough Science, Public Broadcasting System, https://www.pbs.org/weta/roughscience/series3/big_smelt/smelting.html (last checked March 23, 2019)
3. "New Exhibition Highlights Story of the Richest Man Who Ever Lived," Smithsonian, February 5, 2019, https://www.smithsonianmag.com/smart-news/richest-man-who-ever-lived-180971409/ (last checked February 8, 2019)
4. "Antebellum Gold Mining (1820-1860)," North Carolina History Project, http://www.northcarolinahistory.org/commentary/59/entry; "The History of Gold in North Carolina - Gold Fever and the Bechtler Mint, http://goldfever.unctv.org/history; Rebecca Lewis, "The North Carolina Gold Rush," Spring 2006, https://www.ncpedia.org/industry/gold-rush (last checked March 24, 2019)
5. Thomas Jefferson, Notes on the State of Virginia, Prichard and Hall (Philadelphia), 1788, p.24, published onlne by the University of North Carolina Library, Documenting the American South, https://docsouth.unc.edu/southlit/jefferson/jefferson.html (last checked March 24, 2019)
6. Thomas Jefferson, Notes on the State of Virginia, Massachusetts Historical Society, Thomas Jefferson Papers, p.14, http://www.masshist.org/thomasjeffersonpapers/notes/index.php (last checked March 24, 2019)
7. Douglas Phillips, Barnaby Nygren, "An Inquiry into the Validity of the Legend of. Braddock's Gold in Northern Virginia," Fairfax Historical Society, 1982, http://www.fairfaxhistoricalsociety.org/Braddock.pdf (last checked March 25, 2019>
8. "Gold fever grips Lake Anna park,"Free Lance-Star, July 31, 2003, https://www.fredericksburg.com/columns/gold-fever-grips-lake-anna-park/article_c60cc38a-bafd-5dd1-8f81-d7b558092995.html (last checked April 29, 2019)
9. "Plan would put state’s only active gold mine in Goochland," Richmond Times-Dispatch, July 13, 2014, http://www.timesdispatch.com/news/local/central-virginia/goochland/plan-would-put-state-s-only-active-gold-mine-in/article_298a1512-c60b-51a9-9014-91081a002b6a.html; "CU-2014-00005 Application filed by William Kilgore requesting a Conditional Use Permit for mining operations at the old Moss Mine at 4385 Shannon Hill Road," Goochland County Board of Supervisors, July 1, 2014, http://goochlandcountyva.iqm2.com/Citizens/Detail_LegiFile.aspx?Frame=&MeetingID=1007&MediaPosition=&ID=1127&CssClass= (last checked September 4, 2014)


Minerals of Virginia
Rocks and Ridges - The Geology of Virginia
Virginia Places