364 GEOLOGY AND GOLD DEPOSITS OF THE CRIPPLE CREEK DISTRICT. 
On the third or bottom level the dike is followed northwest from the shaft for 
about 100 feet, becoming here much pinched and shattered. Just north of this 
point the drift crosses a well-defined zone, 3 to 4 feet wide, approximately vertical, 
and striking northeasterly, which contains fragments of granite and plionolite. 
It may be a brecciated-phonolite dike, but the presence of basaltic fragments in 
the zone 50 to 60 feet northeast of the point where the basalt dike was last recog¬ 
nized indicates that this may be a plane of faulting. 
All the ore has been extracted from the basalt dike or the accompanying fissure. 
A little ore was taken from the dike at the surface. On level 1 the granite-breccia 
contact is approximately 20 feet north of the shaft. A little stoping has been 
done above and below the level north and south of the shaft. The vein on this 
level is simply a shattered oxidized zone, holding kaolin, and the basalt is not 
recognized. On level 2 the basalt becomes distinct. The contact is in about 
the same relative position as on the level above. Here also a little stoping 
has been done just south of the shaft, above and below the level. Along and to 
the south of the contact on level 3 a fair-sized stope of ore has been mined along 
the dike, the values being mainly along the sides of the dike. The ore was oxidized 
and of good grade. 
The position, size, and value of the ore shoot seems to be independent of the 
granite-breccia contact, though occurring near and roughly parallel to it. No 
cross seams were observed. 
SHERIFF MINE. 
The Sheriff mine, the property of the Sheriff Gold Mining Company, is located 
on the Sheriff claim, on the saddle between Bull and Raven hills. There are several 
shafts from 100 to 200 feet deep on the property. The principal shaft and the 
only one that was being worked in the spring of 1904 is 300 feet deep and connects 
with about 600 feet of drifting and crosscutting. The production of the mine 
is not very large. 
The shaft is sunk in breccia just outside the Bull Hill granite area. In general 
the rock is fine grained and dense, and appears to be largely phonolitic. A basaltic 
dike is encountered about 30 feet southeast of the shaft, on the 45-foot level. It 
is 18 inches wide, strikes N. 38° W., and dips about 80° SW. On the 165-foot 
level the dike is seen 100 feet southeast of the shaft with the same dip and 
strike, but with a width of 4 feet. Ten feet away and parallel to it is a brecciated 
and oxidized zone containing many fragments of basalt. One hundred feet north¬ 
west of the shaft a 4-foot basalt dike strikes N. 15° W. and dips about 75° E.; it is 
probably a branch from the first-mentioned dike. 
Well-defined continuous veins are not shown by the workings, though several 
narrow seams partly filled with quartz are found in the upper levels. 
The values occur principally in minute seams and veinlets in the dense, unoxi¬ 
dized breccia. These seams are filled with carbonates and carry tellurides. The 
average value of what has been mined is probably $40. 
A small ore shoot descends approximately vertically from the surface. The 
shaft was sunk on it and for a depth of 25 feet extracted practically all the ore 
of the shoot. To the south of the shaft the body expanded and a chamber 20 feet 
