Key to Formation Symbols Used on Field Trip Route Maps (Figures 7 and 8)
This trip traverses Middle Ordovician and Lower Ordovician Knox Group strata enroute to American Smelting and Refining Company's (ASARCO) Young mine and mill complex (Stop 1). The Young mine, located near the center of the Mascot-Jefferson City zinc district, is the largest of the operating mines. The ore occurs mainly in collapse breccias which will be observed during an underground mine tour led by ASARCO staff.
The trip retraces the route to Knoxville, then turns southwest to the Sweetwater barite district traversing mostly Knox Group formations. The Stephens barite mine, the only currently active mine, as well as the largest producer over the district's 100-year history, can be seen in passing. The shaft site for the 1970's U.S. Borax Company fluorspar project is just down-dip (southeast) from the Stephens site.
Figures & Tables
Zinc Deposits in East Tennessee
The mining of zinc in Tennessee dates back to 1854 although the presence of zinc minerals had been reported as early as 1844 by Gerard Troost, the first State Geologist. When the Mossy Creek open pit mine, in what is now Jefferson City, Jefferson County, was opened, it became the first mine in what is now known as the Mascot-Jefferson City Zinc District. In these early years, only the oxidized ore was removed, and mining stopped when the sulfide ore zone was reached because a method to treat “hard ore”, as it was called, had not yet been developed.
Mining continued at the Mossy Creek operation until 1858, then ceased through the Civil War years until 1867, at which time the property was taken over by the East Tennessee Zinc Company. This company built a smelter to manufacture zinc oxide, but after only a few months of operation, the company became involved in litigation and mining ceased.
In 1882, the Mossy Creek property was sold to the Eades, Mixter and Heald Zinc Company which operated intermittently until 1894, becoming the first substantial zinc mining company in Tennessee as well as the first to produce significant amounts of sulfide ore. This latter was made possible by the construction of a zinc smelter at Clinton, Tennessee, some 45 rail-miles to the west. The Mossy Creek mine was operated or prospected only sporadically thereafter, and was closed by its final owner, the American Zinc Company, in 1919.
In the meantime, the discovery of lead and zinc ore in the Powell River area of Claiborne and Union Counties, some 30 miles northwest of Jefferson City, caught the attention of the mine operators. In 1883, the New Prospect mine was opened with only the lead recovered. By 1889, Eades, Mixter and Heald had taken over, erected a mill and mined the property intermittently until 1897. The lead was handpicked and shipped to New Jersey while the zinc was barged to the smelter at Clinton. There was little further activity until World War II when the very high grade pillars were robbed.
The only other producing mine in the Powell River district was at Straight Creek. It operated from 1880 to 1894, the latter part of this period by Eades, Mixter and Heald Zinc Company, which also built a mill. Beyond this there was only a short period of exploration and mining from 1906 to 1908 and another effort by Universal Exploration Company in the latter part of World War II.