GENERAL41483

• Permit No: M1995097
• IBM Index Class Name: General Documents
• Doc Name: BIBLIOGRAPHY WITH INTRODUCTION GLOSSARY OF TERMS AND LIST OF MINERALS
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ROLFING PAPER
the latter intersects the No. 2 tunnel. The winze is
inclined at 30° and starts 14 ft. above the Anaconda
crosscut, from which it follows the breccia down dip for 45
ft., then extends vertically down another 15 feet. The
uranium occurs in the black carbonaceous matrix of the
breccia [breccia II] which also contains galena, sphalerite,
and silver. In the Kassick stope the areas of breccia that
contain the most conspicuous amounts of pyrite and
chalcopyrite are also highest in uranium. There is
apparently no quantitative relationship between uranium and
lead, zinc and silver. Most of the pink barite showed
elevated radioactivity [in this area], with one sample
assaying at 61.5 ounces Ag/ton and 0.165$ U,Oe. The uranium
mineral, thought to be pitchblende, cannot be detected
megascopically, and is too fine to define microscopically;
uraniferous portions of the breccia can be detected only by
geiger counter. The uranium, with the exception of the
goslarite mentioned above, appears to be localized at or
near the hanging walls of the cross faults.
Most of the uranium is thought to be hydrothermal
pitchblende. Its association with primary galena and
sphalerite in the breccia suggests deposition during
(Spurr's) third stage of mineralization."' Association with
pink barite and native silver, both probably secondary,
indicates that at least some uranium is also secondary.
Conclusions and Recommendations, Smug4ler Mine, pp. 23-24.
Uranium mineralization was found in and near the Kassick
stope of the No. 2 tunnel level. Based on samples taken,
reserves of 120 tons of ore containing 0.148 U,OB were
calculated, with another 120 tons at the same grade
inferred. A drilling program to further define this orebody
and its possible extension was recommended.
D. P. ROHLFING, ASPEN'S SILVER MINES, 2S THE MINES MAGAZINE (N0. 1~), 29-34
(1935).
Rohlfing's paper, which is only semi-technical in nature,
was published with some variations in several journals in
the 1930s (see footnote 88, post). It is a good summary of
the history of discovery and development of the Aspen mining
district as well as a reinterpretation of the geology of the
" SPURR REPORT 313-315, Part I, ante p. 9.
Bruce A. COl11RS - 2(1 - BIBLIOGRAPHY