286 GEOLOGY AND GOLD DEPOSITS OF THE CRIPPLE CREEK DISTRICT. 
roasting. In 1904 a 150-ton mill was in operation, but a much larger one is now 
(1905) in course of construction. The Ironclad mine is developed by a vertical shaft 
690 feet deep, with seven levels, and at least 1,500 feet of drifts and crosscuts. The 
elevation of the collar is about 10,425 feet. Level 7 is 660 feet below the collar. 
The country rock consists throughout of thoroughly oxidized breccia of normal 
type. Above level 4 the ore bodies consist of irregular masses of soft, oxidized 
breccia, with many small seams of comb quartz showing radial structure. On 
level 4 a well-defined vein begins to appear, striking northeasterly and dipping 
about 70°'SE.; the same vein has been reached by crosscuts on all of the lower 
levels; it is from 1 to 6 feet wide and consists chiefly of soft, brown, clayey vein 
matter, with seams of comb quartz. No tellurides remain; copper stains are often 
found, and a specimen from between levels 6 and 7 contained a little tetrahedrite, 
with chrysocolla, the former inclosed in quartz. Fluorite seems to be absent or 
entirely decomposed in the main vein, but near the end of the crosscut on level 7 a 
parallel northeasterly seam, with crushed fluorite, was cut. Fifty feet south of the 
shaft on level 7 another northeasterly vein was cut, dipping 50° SE.; this is said to 
contain some lead. It shows a streaky mass 1 foot wide mingled with clay and limon- 
ite, but consisting chiefly of celestite or sulphate of strontium, in part crystallized. 
The pay shoot on the Ironclad vein dips southwest on the plane of the vein 
at an angle of about 70°. Its greatest horizontal length is 75 feet. The shoot is 
continuous from level 3 almost down to level 7, but on the latter contains only 
low-grade ore. A fair amount of low-grade ore is claimed to exist on levels 5, 6, 
and 7 outside of the richer pay shoot. 
A thick, well-defined quartz vein, with northeast trend, and containing much 
smoky comb quartz, is encountered between the surface pits on the Magna Charta 
claim and the Ironclad shaft; it has been traced for several hundred feet up toward 
the summit of Ironclad Hill. This same vein is cut by a tunnel from the Magna 
Charta claim, and by a crosscut from a shaft 150 feet deep on the same property. 
It is said to contain only low-grade ore. 
The shaft just mentioned enters hard pyritic breccia a short distance below 
the surface and evidently marks the southeasterly limit of that area of very deep 
oxidation which characterizes Ironclad and Globe hills. The oxidized ore milled 
in the cyanide works of the Homestake Mining Company has thus far been extracted 
from the surface between this shaft and the prominent vein mentioned in the pre¬ 
ceding paragraph. It is reported to average $4 to $5. The South Park shaft was 
sunk in breccia near the Ironclad some years ago to a depth of nearly a thousand 
feet. Little exploratory work was done and it is stated that nothing of value was 
found. 
HOOSIER MINE. 
The Iloosier mine is situated just north of Hoosier Pass and about half a mile 
north of Globe Hill. It is the property of the Grafton Gold Mining Company. 
The total production of the mine is estimated at $360,000. Dividends have been 
paid from the royalties received from lessees. The workings consist of an incline 
shaft 300 feet deep and a vertical shaft about 600 feet deep, in which sinking is in 
progress. The drifts and crosscuts probably aggregate 2,000 feet in length. The 
elevation of the shaft collar is about 10,335 feet. 
