272 GEOLOGY AND GOLD DEPOSITS OF THE CRIPPLE CREEK DISTRICT. 
somewhat mineralized throughout. Many of the lodes are of short horizontal 
extent and not always persistent in depth. The three most important mines are 
the Abe Lincoln, C. O. D., and Gold King. The latter was the first regularly pro¬ 
ducing mine in Cripple Creek. In 1904 only the first-named was actively worked. 
C. O. D. MINE. 
The C. O. D. mine, operated by the Rebecca Gold Mining Company, is one of 
the oldest mines of the district. In 1894, when Penrose examined it, the depth 
attained was 220 feet. At the present time the shaft is 800 feet deep, ten levels are 
turned, and the total developments consist of about 4,000 feet of drifts, extending 
chiefly northward, level 8 attaining a distance of 600 feet from the shaft. The 
elevation of the collar is 9,821 feet. Except in a very limited way by lessees, the 
mine was not worked in 1903 or 1904. The bottom was dry in the latter year. 
The total production is given as $594,000, and the dividends amount to about 
$150,000. The C. O. D. vein is contained in normal fine-grained breccia, with a 
moderate amount of disseminated pyrite and carbonates. Level 7 is said to run 
out in schist 130 feet south of the shaft. A crosscut, 300 feet long, toward the 
east on level 8, remains throughout in breccia. The vein is a sharply defined fissure 
striking about N. 10° E., and dipping about 84° in an east by south direction. 
The Gold King vein is said to have been cut in a crosscut on level 5 about 200 feet 
west of the shaft. The crosscut east on level 8 cuts two veins 200 and 300 feet 
distant from the C. O. D. and approximately parallel to it. Both are oxidized and 
show no pay ore. One of them is believed to represent the extension of the Proper 
vein. The ore in the C. O. D. is of the usual type, with calaverite, quartz, and 
fluorite. Fresh tellurides were found close to the surface. Much of the ore aver¬ 
aged 5 ounces per ton. A small cross seam containing tetrahedrite was struck on 
level 10 and is reported to have yielded assays of 850 ounces silver and 5 ounces 
gold per ton. 
Penrose says of the upper levels that the vein is a well-defined fault fissure, 
with grooves and slickensides, and with numerous subordinate cracks on either side 
of the main fissure. On level 8, where seen in 1904, the vein is marked by several 
narrow fissures and has the ordinary appearance of the sheeted zones character¬ 
istic of Cripple Creek veins. In one place the vein is slightly faulted by cross 
seams. From the discovery shaft to level 6 the ore shoot pitched southward 
toward the main shaft at an angle of 40°. Its length along the levels was about 100 
feet. Below, this point its pitch became reversed toward the north, but at the 
same time became much poorer. Near the main shaft ore was stoped from level 
8 to level 6, but the ore seams are said to have been narrow, at the same time spread¬ 
ing over a wider space. On levels 9 and 10 little if an} T ore has been stoped. 
PROSPECTS NEAR THE C. O. D. 
The partly oxidized breccia near the C. O. D. and close to the contact with 
the schist contains many little seams of fluorite and quartz. Much of the surface 
material is rich enough for shipment, but none of these deposits has proved to be 
of great extent. 
