GENERAL41483

• Permit No: M1995097
• IBM Index Class Name: General Documents
• Doc Name: BIBLIOGRAPHY WITH INTRODUCTION GLOSSARY OF TERMS AND LIST OF MINERALS
• Media Type: D
• Archive: No

INTRODUCTION
table" where oxygenated groundwater, circulating through the
breccias and other relatively open cavities and fractures of the
carbonates of the Aspen district, removed the sulfides and other
chemicals originally combined with it, leaving behind massive
deposits of native silver. One native silver "nugget" reached
nearly 2,000 pounds in weight. Elsewhere, extensive deposits of
delicate, intricately-interwoven "wire" silver were found.
Unfortunately, production records are not sufficiently detailed to
determine how much native vs. combined silver was produced.
In a few areas, including the top of an unnamed raise
immediately inside the portal of the Smuggler No. 2 tunnel, the
supergene zone extends virtually to the surface. In this specific
location, thin glacial sands and gravels were enriched by
circulating groundwater and even surface samples are anomalously
high in typical ore minerals.
Mining Methods
The author has found virtually no detailed accounts of the
mining methods utilized in the Aspen district. However, from
general descriptions that are available (see BIBLIOGRAPHY) and
examinations of workings in both Aspen mountain (Compromise tunnel
and associated workings) and in the Smuggler No. 1, No. 2, and
Clark tunnels, as well as interconnecting workings, it is apparent
that the mines were developed in a manner typical of the late 19th
and early 20th centuries in moderately- to steeply-dipping
deposits.
Tunnels and shafts were developed, mostly in "country rock,"
to access the deposits which were reached by crosscuts or drifts.
Raises were driven from the relatively level tunnels, drifts, or
crosscuts, usually in ore, and expanded into stopes from which most
of the ores were produced. Stoping methods and dimensions varied
widely. Because of the general competence of the hanging- and
foot-wall rocks, massive timbering such as used in other districts
was apparently unusual in the Aspen district. Indeed, stopes with
dimensions of up to 60 ft. in width, 250 ft. in length, and over
1,500 ft. in depth have stood open, without timbering, for nearly
100 years. In all likelihood slabbing from level-connected raises,
from the top down, creating a shrinkage stope from which ore was
loaded through chutes into ore cars in the openings below, or in a
similar fashion from raises as opened upward, were the most typical
mining methods. Regardless of variations, development openings in
country rock were as small as possible, to minimize the necessity
of handling non-paying rock. Stopes, and drifts, raises, and other
openings in ore were limited as much as possible to profitable
" Today the approximate level of the Roaring Fork River but, of
course, in the past not necessarily as low or as high.
Bruce A. Collins - xxvi - SNUCCLeR BISLIOGRAPSx