428 GEOLOGY AND GOLD DEPOSITS OF THE CRIPPLE CREEK DISTRICT. 
In the Revenue the most southerly is the Revenue vein, known on all upper levels 
down to 7, while it is less well developed on 8 and 9. It has several spurs. The 
Sigel vein, opened on level 6 at the Vindicator boundary, lies in the continuation of 
the Revenue, but the actual connection has not been established. About 100 feet 
north of the Revenue is the La Bella vein, known on levels 3 to 9, inclusive. A vein 
carrying small values was 
cut near the end of the long 
southwest crosscut on level 
9; it occured in the loose, 
unaltered breccia which 
there forms the country 
rock. 
OXIDATION. 
Oxidation has pene¬ 
trated to the bottom level 
along most of the seams, 
and the ores invariably 
pan free gold. Calaverite 
is, however, found occa¬ 
sionally, and one vein, the 
Middle, on level 8, is not 
oxidized, possibly because 
not reaching: to the surface. 
The natural water level is 
not positively known, but 
is believed to have had a 
depth of about S00 feet. 
VEIN STRUCTURE AND ORE. 
The veins as a rule are 
narrow sheeted zones, in 
many cases with a pro¬ 
nounced central seam and 
not quite so tight as in the 
Vindicator, though the 
rock is often very fresh 
within the veins. The 
seams are coated by 
quartz, dolomitic carbon¬ 
ates, and a little fluorite; celestite needles also occur. Native gold is the principal 
ore mineral, with a little unchanged calaverite and occasionally a little pyrite, 
galena, and zinc blende. A spur vein along the phonolite dike at the Theresa East 
vein contains much galena and zinc blende, but carries low values in gold. The 
breccia and latite-phonolite throughout the productive ground contain a little 
pyrite and dolomite, but the alteration is never pronounced. The alteration is 
strongest within the veins and, as shown by the crosscut on level 9, is apt to disap- 
