412 GEOLOGY AND GOLD DEPOSITS OF THE CRIPPLE CREEK DISTRICT. 
with the Findley; but at the crossing with the Shurtloff vein, which is barren on 
level 11, it proved valueless for 10 feet on each side of the intersection. Near the 
end of the drift on this cross vein values were suddenly cut off by a northwestward- 
trending seam. 
To sum up, no ready explanation can be given for the occurrence of the main 
shoot, while the Shurtloff shoot seems dependent on the split in the vein, and the 
large bod} 7- on the cross vein conditioned by the crossing with the Findley. It is 
remarkable that the next crossing with the Shurtloff should be attended by a decided 
impoverishment. 
HULL CITY MINE. 
PRODUCTION AND DEVELOPMENT. 
The Hull City mine is owned by the Independence Consolidated Mining Com¬ 
pany, and consists of an almost square area of 39 acres, except for two claims of 
Vindicator property which project into it from the southeast. The total produc¬ 
tion approaches $2,000,000, of which $900,193 was extracted up to the end of 1899 
and $999,174 during the three years from January 1 , 1901 to January 1 , 1904. 
During 1904 the mine was worked on a smaller scale by lessees. 
The developments consist of a main vertical shaft 1,265 feet deep, with eleven 
levels turned. The elevation of the collar is 10,279 feet. The levels are somewhat 
irregularly placed, as shown on fig. 54. Level 11 has an elevation of 9,029 feet. 
Six hundred feet to the southeast, near the southern boundary, is the King or 
Vaughn shaft, also known as the Glorieta, with a collar elevation of 10,204 feet 
and a depth of 860 feet. This has twelve levels, the upper ones being close together; 
level 4 corresponds about to main level 1, and level 12 to main level 8. There are 
also many small shafts less than 400 feet in depth. The developments have a 
total length of several miles. On level 11 the crosscut has not yet reached the 
vein. In April, 1904, water stood 1,055 feet below the collar, and the two lowest 
levels were inaccessible. During 1903 the pumps kept the mine dry, raising 300 
gallons a minute. 
GEOLOGICAL FEATURES. 
The principal rock on the surface, as well as on all lower levels, is a normal 
breccia in which latite-phonolite usually predominates. The change to latite- 
phonolite, which occurs both near the Findley line and at the south end of the work¬ 
ings, is gradual. A very prominent dike of latite-phonolite traverses the property 
for a distance of 1,000 feet from the Findley to the Vindicator boundary. Its strike 
is northwest or north-northwest, its width from 9 to 15 feet, and it stands nearly 
vertical. Southward it merges into the latite-phonolite of the Vindicator, while 
northward it seems to disappear shortly before the Findley line is reached. The 
dike is prominently porphyritic by large orthoclase crystals and more nearly 
approaches the trachytes in appearance than most of the latite-phonolites of the 
district. It occurs on all the levels below 3, but as the upper workings are inac¬ 
cessible, its continuation to the surface could not be shown. A crosscut on level 
4 extends 500 feet to the northeast and passes through two dikes of phonolite and 
two of latite-phonolite; at its extreme end it cuts a basic dike. 
