318 GEOLOGY AND GOLD DEPOSITS OF THE CRIPPLE CREEK DISTRICT. 
second class range in strike from north to X. 10° E. and are represented by the Smith- 
Reilly, Xortli Star, and Ingham lodes. The North Star lode is about vertical, the 
Ingham dips very steeply west j while the Smith-Reilly has a westerly dip of about 
70°. The so-called Walter lode, followed on the 550-foot level (fig. 31, p. 316), has 
a general strike of N. 15° W., and so does not belong strictly with either of the two 
main sets of lodes. Another lode, exploited on the 550-foot level about 100 feet 
east of the Smith-Reilly and called the Mattie D. lode (though its identity with the 
Mattie D. as known higher up the hill is not established), strikes X. 30° E., so that 
it is intermediate in strike between the lodes of the two general classes. Like nearly 
all the other lodes in this part of Raven Hill, it dips northwest , the angle being about 
70°. The Mattie D. lode, as seen in the Mattie D. tunnel and incline, has an average 
northwest dip of about 45°, though in some places the dip is only 20°. It intersects 
the Ingham lode, neither lode being displaced or showing any distinct difference in 
age. The relative positions of the various lodes are shown in fig. 31 (p. 316). 
The relation of the Doctor and Jackpot veins has been much discussed and 
constituted an important question in the litigation that led to the consolidation of 
the two mines. They are supposed by some to be merely parts of the same zone 
of Assuring. Others maintain that the Jackpot vein has a slightly different strike 
from the Doctor vein and is more nearly vertical. Those who hold the latter view 
believe that the Doctor and Jackpot veins intersect at a small angle and that the 
Doctor vein carries ore only at this and other intersections. At the time of visit the . 
mine workings were not in a condition to allow a satisfactory decision to be reached 
on this mooted point, and as the observed relations are most readily accounted for 
on the supposition that the so-called Doctor and Jackpot veins are really part of one 
persistent zone of Assuring, this zone will be referred to in this report as the Doctor- 
Jackpot lode. 
CHARACTER OF ORE. 
It is not possible in the present condition of the workings to give a detailed 
account of the ore of these mines. The large and rich shoots of the Doctor-Jackpot 
lode have been worked out, and accurate information concerning the character of 
ore that occurred in the abandoned stopes is difficult to obtain. In the lower 
levels, below the zone of oxidation, two fairly distinct types of ore are found in the 
Doctor-Jackpot lode. One of these shows the usual association of calaverite or 
sylvanite with quartz, Auorite, and often a little dolomite, in the veinlets of the 
sheeted zone. Some of the crystals of calaverite project into small vugs, but in 
many cases are inclosed in a compact aggregate of quartz and purple Auorite. This 
ore is by some considered characteristic of the Doctor lode. The other type is 
characterized by the presence of tetraliedrite, associated with pyrite, quartz, and 
dolomite, but with little or no Auorite and, so far as observed in the few specimens 
obtainable, no visible tellurides. Some of the specimens of this ore show a deAnite 
mineralogical sequence. Pyrite and tetrahedrite crystalized Arst on the walls of the 
Assures, accompanied by a mineral, probably celestite, crystallizing in rather slender 
prisms of rhombic cross section. Deposition of quartz, with sometimes a little 
Auorite, followed, and during this deposition the prismatic mineral was altered to 
hollow siliceous pseudomorphs. The alteration seems to have consisted in a partial 
