East Tennessee is lucky to have so many historic locations; Civil War battlefields, famous courthouses, and Oak Ridge National Laboratory, just to name a few. However, one rather unique portion of Tennessee history took place in far Southeast Tennessee, away from any large cities. Very few have heard of Ducktown, and just as few recognize that Appalachia actually produced something from its mines other than coal or limestone. Instead, the Burra Burra Mine in Ducktown, TN yielded millions of tons of copper ore in the early 1900’s.
The geologic setting around Ducktown is quite different than the rest of Tennessee. The rocks here, from the Copperhill Formation, were formed at high pressures that produced metasandstone and schist. The schist contains garnet, and rocks deep in the mine contain staurolite and kyanite, both of which indicate high metamorphic grade. Other indicators of high pressure include overprinted foliations (parallel to bedding) and crenulations. All of these rocks occur in the Copper Basin (cleverly named for the abundance of copper ore) which is also referred to as the Ducktown Basin (also cleverly named).
The method of mining is also different than that of many Appalachian operations. Much of the coal and limestone mining is done via quarrying, shallow subsurface mining, strip mining, and mountaintop removal, but the Burra Burra Mine operated using deep vertical mine shafts that penetrated nearly half of a mile into the ground. This is possible due to the large volumes of ore, as opposed to relatively thin beds of coal. However, these shafts eventually led to a large collapse of the mine after the operations ceased, resulting in a huge sinkhole.
Ducktown is infamous for its history of smelting its ore. The TN Copper Company smelted its sulfur-rich raw ore in mass quantities, releasing large amounts of sulfur dioxide into the atmosphere. This increased the acidity of the soil by devastating amounts and killed virtually all plant life for miles around. During this time, Ducktown more closely resembled the Midwest than it did Southeast Tennessee and the landscape was transformed from forests to an eroded desert. This led to efforts by the company to reverse the pollution damage after several lawsuits.
Today, the mine itself is closed off for safety reasons, but the Ducktown Basin Museum gives tours of the many buildings. Even better, for a small fee, the museum allowed Shadowfax and me to explore small spoil piles left over from the mine that were packed with copper and sulfide minerals such as pyrite and pyrrhotite. I want to thank the generous staff for taking time out of their day to drive to the museum and give us entry to the piles since the museum was closed that day due to inclement weather.
I would also like to introduce Shadowfax, a fellow geology undergraduate who will have many exciting adventures to post soon.
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