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- Title
HAMME (TUNGSTEN QUEEN) MINE TAILINGS, VANCE COUNTY, NORTH CAROLINA: MINERAL CHEMISTRY OF POTENTIALLY RECOVERABLE HUEBNERITE-WOLFRAMITE AND SULFIDE MINERALS.
- Authors
CHAUMBA, JEFF B.; REID, JEFFREY C.; PARKER, JOHNATHON C.
- Abstract
The Hamme (Tungsten Queen) mine, Vance County, N.C., was worked for wolframite-huebnerite and it also produced minor amounts of sulfides (copper and silver). At this deposit, there are about 1 million metric tons of quartz-dominated tailings containing about 0.25% WO3, with accessory fluorite and very minor sulfides - mostly galena with accessory silver concentrations. We undertook a petrographic and mineral composition study of the huebnerite, galena, and chalcopyrite to help place constrains on the origin of the deposit. Under the microscope, huebnerite shows zoning which is not reflected in the chemistry of the mineral. All minerals investigated have concentrations which show very limited compositional ranges. Huebnerite is strongly enriched in WO3 (73.5-75.5 wt.%), MnWO4 (97.3-99.7%), and Mn (1.037-1.065 atoms per formula unit, apfu) but is depleted in Fe2+ (0.040-0.029 apfu). Sulfide mineralogy is composed of galena with concentrations of Pb (83.0-85.8 wt.%) and S (13.2-13.9 wt.%), and chalcopyrite with concentrations of Cu (33.8-38.2 wt.%), Fe (29.7-29.9 wt.%), and S (34.5-34.6 wt.%). Sulfur concentrations of galena in Hamme (Tungsten Queen) deposit are comparable to other lead deposits elsewhere. Coarser-grained and anhedral galenas have slightly higher Pb concentrations than those which occur either as rims to huebnerites or as 'intercumulus phases' between huebnerites. Hamme (Tungsten Queen) deposit huebnerite compositions reported here are comparable (although slightly enriched in Mn but depleted in Fe2+) to other huebnerite deposits such as Round Mountain in Nevada and some huebnerites from Portugal. Compared to other wolframite deposits, the Hamme (Tungsten Queen) deposit is more depleted in Fe2+ and highly enriched in MnWO4, an indication of a lack of substitution of its Mn by other cations. Based on findings from this study, it is concluded that Hamme (Tungsten Queen) deposit huebnerites were formed early in the history of formation of the deposit and were little affected by a later hydrothermal event that affected the district. Galena inclusions in huebnerites and coarser-grained galenas, which are comprised of slightly higher Pb concentrations, are interpreted to be primary, likely formed at the time of formation of the enclosing huebnerites, than galenas which occur as 'intercumulus' grains and are also slightly depleted in Pb. These latter galena crystals likely formed later, probably during metamorphism and associated hydrothermal alteration.
- Subjects
VANCE County (N.C.); NORTH Carolina; MINES &; mineral resources; METAL tailings; GEOCHEMISTRY; HUEBNERITE; WOLFRAMITE; SULFIDE minerals
- Publication
Southeastern Geology, 2015, Vol 51, Issue 1, p33
- ISSN
0038-3678
- Publication type
Article