Thompson Mine, Nacoochee, White County, Georgia, USAi

Regional Level Types
Thompson Mine	Mine
Nacoochee	- not defined -
White County	County
Georgia	State
USA	Country

The White County (Thompson) mine, on lot 102 of the 3d district, about 1 1/2 miles southeast of Nacoochee, is owned by Messrs. Henry and Humphries of Habersham Mills, Ga. It was idle when visited in 1934 but had been operated for a short time in 1932 by Messrs. Fleming and Scott. The workings include a large number of shallow shafts, and many adits, drifts, and open cuts. About 700 feet of the adits was accessible in 1934. Many of the small open cuts are old stopes worked upward from shallow adits.

Surface exposures in the area around the workings are better than those elsewhere in this part of the goldbearing region. Most of the exposed rock is saprolitic, but comparatively fresh rock is found in the adjacent stream valleys and in some of the open cuts. The country rock is banded amphibole gneiss and mica gneiss, both of which are cut by intrusive masses of a coarse-grained light-colored granitic rock. The amphibole gneiss is generally similar to that throughout north Georgia, but it includes a dense, fine-grained, greenish-black phase that is conspicuous because of its resistance to weathering. The mica gneiss is medium-grained, and not nearly as schistose as most of that exposed near other gold deposits in Georgia. In many hand specimens it exhibits textures and structures resembling those of a sheared intrusive or coarse flow. In both the amphibole gneiss and the mica gneiss the foliation strikes about N. 50° E. and dips steeply either northwest or southeast. The granitic rock forms irregular masses cutting across the foliation in the gneiss and is not itself noticeably gneissic. Locally a pegmatitic phase is common. The relations of the various rock types are well exposed both on the surface and underground.

The mineralized zone consists of numerous quartz stringers and layers, in places spaced closely enough to permit mining the lode as a whole. In general the quartz layers are nearly parallel to the foliation of the gneiss, but a few stringers cut across it. Yeates gives a good description of the lode, which was being mined at the time of his visit. He states that the lode consisted of quartz stringers in a zone 6 to 10 feet wide. In the workings accessible in 1934 the quartz is generally confined to zones less than 20 inches wide; many of these zones are nearly solid quartz. In some places several of these zones lie side by side, or in step-like arrangement, separated by poorly mineralized country rock. Quartz veins up to 4 inches in thickness have a fairly uniform width although they gradually pinch and swell along the strike and dip. Ragged remnants, as well as more compact fragments, of country rock are abundant in the quartz. The rock adjacent to the quartz is generally platy and sericitic, and grades outward into the normal country rock. Mineralized lode quartz is mostly confined to the mica gneiss near amphibole gneiss bands although a few streaks of quartz appear in the amphibole gneiss and the granite.

Some shearing has taken place along the lode. This shearing is much obscured by later mineralization, and in a few places there are small post-ore fractures.