Little Hawk Ridge mine

Mica Mine in Mitchell county, North Carolina, this site also known as John

Little Hawk Ridge (John) mine

Principal periods worked 1920, 1924, WWII, 1950's
Workings Cut 220 long, 50 deep, shaft 50, 6 adits, large stopes 400 long, 10-100 deep.
Description of muscovite Reddish-brown, hard, minor ruling, bending. Some "A" structure, tied, mineral inclusions.
Production Large sheet
Shape Pinch and swell, elongate lens.
Size 1-12 T, avg 5
Strike NE
Dip SE
Plunge E
Relation to wallrock Partly concordant
Wallrock Interlayered biotite and Hornblende gneiss
Extent of weathering Weathered (25-50 ft).
Remarks Pl-Q-M wall zone, medium grained; Pl-Q-P intermediate zone, medium to coarse grained, Q-P core, in southwestern part; northeastern part unzoned Pl-P-Q-M pegmatite; accessory biotite, sericite, garnet pyrite.
Source of information USGS, DMEA

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