Fall Branch mine

Mica Mine in Avery county, North Carolina

Fall Branch mine

Principal periods worked Pre-WWII
Workings Caved
Description of muscovite Light green, small, bent, ruled
Production Moderate scrap
Size Largest 10 T
Strike NE
Dip NW
Relation to wallrock Concordant
Wallrock Interlayered hornblende and biotite gneiss
Remarks Pl-Q-P-M pegmatite, fine grained; accessory garnet, epidote.
Source of information USGS

Geographic context

Abbreviations

Principal periods worked
WWI World War I
WWII World War II
int intermittent
Production
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