UNAWEEP COPPER DISTRICT^ COLO. 
23 
addition of silica, cementing the sandstones into a resistant quartzite 
for several feet from the fissure, as is well illustrated 1 to IJ miles 
east of Grant’s ranch. 
The prevailing vein minerals are calcite, quartz, and a little 
fluorite, together with pyrite and chalcopyrite and in some deposits 
rather abundant hematite. 
Oxidation has not been very extensive, as most of the ore contains 
a rather large percentage of primary sulphide, even in the shallow 
workings. The oxidation has resulted principally in the formation 
of limonite and malachite. A little chalcocite was noted, but there 
has apparently been very little sulphide enrichment. The copper 
sulphate resulting from the oxidation of chalcopyrite has apparently 
reacted with the calcite of the gangue to form the relatively stable 
copper carbonate. There seems no reason for believing that there 
has been any considerable migration of the copper or that in the 
district in general richer or larger ore bodies than those near the 
surface are to be expected at greater depth. It is of course possible 
that in an individual deposit the outcrop may chance to be a narrow 
or lean portion of the vein and that it will be found to be larger and 
richer at greater depth. It should be borne in mind, however, that^ 
the reverse is quite as likely to be true. 
There has been considerable prospecting in the district, but most 
of the properties were idle at the time of visit, and it is therefore 
impossible to give an accurate description of the different prospects. 
The deepest mine is the McKinley, which has been developed by 
a shaft said to be about 600 feet deep. It is stated that at a depth 
of about 150 feet a small body of ore was encountered. The Kancy 
is developed by two shafts, each reported to be more than 100 feet 
deep, and by a tunnel about 300 feet long. A shoot of ore was found 
near the surface and was followed to a depth of more than 50 feet, 
and the writer was informed by Mr. J. S. Shaw that 21 cars of ore 
averaging 16 per cent of copper were shipped from this deposit. 
The ore on the dump contains pyrite and chalcopyrite with abundant 
hematite. 
The Chance claim is developed by a tunnel 700 feet long connect¬ 
ing with a shaft more than 300 feet in depth. The tunnel follows a 
basic dike and disclosed small bodies of vein minerals between the 
dike and the granite walls. 
The Bell claim is believed to be on the same vein as the Chance 
and has been developed by a shaft, said to be about 120 feet in depth, 
which encountered some ore. There are numerous other claims in the 
district on which some development work has been done and in 
which some ore has been found. 
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