Corn mine

Mica Mine in Avery county, North Carolina

Corn mine

Principal periods worked 1920, WWII
Workings Opencuts, inclines, drifts for 300 along strike.
Description of muscovite Green, "A" structure, cracked, bent, concentrated near core; Brown, bent, cracked, stained, concentrated along hanging wall, footwall, and in footwall rolls.
Shape Pinch and swell.
Size 0.5-8 T >300 L
Strike NW
Dip NE
Relation to wallrock Partly concordant
Wallrock Mica gneiss
Extent of weathering Unweathered
Remarks Pl-Q-M wall zone, fine to coarse grained; Q core. Platy structure and deformed mica common. Some kyanite in wallrock.
Source of information USGS, CMC

Geographic context


Principal periods worked
WWI World War I
WWII World War II
int intermittent
Small < 500 lb
Moderate 500-10,000 lb
Large > 10,000 lb
Size of pegmatite
D depth
L length
T thickness
avg average
Internal structure
B biotite
F feldspar
M muscovite
P perthite
Pl plagioclase
Q quartz
Source information
CMC Colonial Mica Corporation
DMEA Defense Minerals Exploration Administration
OME Office of Minerals Exploration
USGS U.S. Geological Survey
OF USGS open-file reports and maps