360 GEOLOGY AND GOLD DEPOSITS OF THE CRIPPLE CREEK DISTRICT, 
LODE SYSTEMS. 
The granite for a distance of about 200 feet from the main phonolite mass is 
cut by a number of fissures which, for the most part, strike about N. 35° E. This 
strike is roughly parallel with the longer axis of the Beacon Hill phonolite intrusion 
and with the numerous fissures in granite in the El Paso workings on the other side 
of the hill. The individual lodes composing this general fissure zone range in strike 
from N. 10° E. to N. 40° E. They dip usually to the northwest, the angles ranging 
from 60° to 90°. The principal lodes are the Prince Albert, Gold Dollar, Lindsay, 
Mabel M., and Parker & Head. Owing to the irregular and disconnected character 
of the underground workings the mutual relations of these lodes are not clear. It 
is possible, for example, that the Gold Dollar and Lindsay are really parts of one 
lode, but the connections through the Zoe mine are not such as to establish this 
identity. The Gold Dollar lode has a dip of about 70°, while the dip of the Lindsay 
is 60°. In general the fissure zones are not very persistent and where they do not 
contain ore are not always distinguishable from other fissures of similar trend, but 
of no known economic importance. The fissures frequently branch and intersect 
one another, but, so far as known, none of the intersections show faulting. 
The Gold Dollar and Lindsay lodes constitute practically the southeastern 
boundary of the known zone of productive fissures. The other lodes lie between 
these two and the Beacon Hill phonolite and are usually more nearly vertical. 
CHARACTER OF ORE. 
The ore in these mines occurs as calaverite or sylvanite associated with quartz. 
No fluorite was observed in the ore seen at the time of visit. A specimen of ore 
from the Prince Albert mine was obtained by Penrose in 1894, and the telluride 
within it was examined by Hillebrand and Penfield. It proved to be calaverite.® 
Palache 6 more recently has described a telluride from the Mabel M. mine, and has 
shown it to be sylvanite. The ore, as a rule, is unoxidized, though traces of oxida¬ 
tion can occasionally be detected along some of the more open fissures even in the 
deepest levels. 
PAY SHOOTS AND LODE STRUCTURE. 
With the exception of the main Prince Albert ore body and some small pay 
shoots in phonolite in the Beacon claim, the ore in these mines occurs in narrow 
sheeted zones in granite. The Lindsay lode lies on the east side of a phonolite dike, 
but the ore is all in the granite. There is usually one main fissure, less than an 
inch in width, in which occur quartz and calaverite or sylvanite, the tellurides 
being found in the vugs of the quartz veinlet. This main fissure is often accom¬ 
panied by minor, less persistent fractures, which may also contain quartz and tel¬ 
lurides. The pay shoots are comparatively small, being rarely over 50 feet in 
length and not extending to great depth. The known ore in the Parker & Head 
and Lindsay lodes all occurs at less than 300 feet in depth. In the Mabel M. and 
a Cross, Whitman, and Penrose, R. A. F., jr., Geology and mining industries of the Cripple Creek district, Colorado: Six¬ 
teenth Ann. Rept. U. S. Geol. Survey, pt. 2, 1895, pp. 133-136. 
b Notes on tellurides from Colorado: Am. Jour. Sei., 4th ser., vol. 10, 1900, pp. 419^122. 
