kansome.] DEPOSITS OF RED MOUNTAIN REGION. 241 
ore deposits which are of different types from those just described. 
The conspicuous alteration which lias given the rocks of Red Moun- 
tain their brilliant tints is limited on the northeast by Grey Copper 
Gulch, and it is to this area of altered rock that the peculiar chimney- 
like deposits of the Yankee Girl type are confined. 
The Saratoga was located in 1883, and has produced in all about 
$125,000. A far greater sum than this has been expended in develop- 
ment and in the erection of an expensive lixiviation plant. Consider- 
able work was done in 1886, and in 1889 and 1890 about 100 men were 
employed. Since 1890 work has been confined to extracting pockets 
of ore with two or three men. 
The lowest formation exposed at the Saratoga mine is a massive 
quartzite, white or light buff in color, which outcrops near the mill, 
with no recognizable bedding. Withoul much doubt this quartzite 
represents a portion of the Algonkian series, here rising a little above 
the level of fronton Park. Lying unconf ormably upon this quartzite 
is a locally nearly horizontal formation of limestone, sometimes thinly 
bedded, which is probably of Devonian age and to he correlated with 
the limestone occurring south of Silverton. The thickness of 'his 
limestone is no1 known, hut is apparently somewhal variable, and in 
places it certainly reaches a thickness of 75 feet. Some thinly hec 
portions at its top appeal- to have been silicified, forming a mat* 
resembling quartzite a1 first glance, but composed of vein quartz con- 
taining numerous little vugs. Above the limestone there occurs a 
thin st rat um of telluride conglomerate, originally composed largely of 
limestone pebbles, hut now silicified and with its conglomeratic < I 
acter obscured. This appears to represenl the rapidly thinning < - 
ern margin of this conglomerate, for ii is not recognizable a short 
distance within the hill, in the mine workings, where the vole; 
breccias of the Silverton scries, containing some massive andesite, lie 
upon the limestone. 
The ore body of the Saratoga occurs in the Limestone, ami probal 
in part in the telluride conglomerate, and is very irregular. 
the surface of the hill if is a mass of soft, rust-colored, oxidized n 
rial, easily worked with pick and shovel, and traversed by numei 
irregular seams of soft clay gouge. The pay ore occurs along these 
seams or gouges and is chiefly a carbonate of lead carrying si: 
probably as chloride. Residual kernels and masses of white erys 
line limestone are of frequent occurrence, surrounded by the i i 
decomposed material of the ore body. The best ore is found rev 
on the oxidized upper surface of a mass of iron pyrite. This j; . 
varies greatly in thickness, and in what is known as the lower 
tunnel it is nearly 100 feet thick — a mass of nearly pure, crumbling 
pyrite, resting on the quartzite, or occasionally on limestone, wken 
the latter has not been wholly replaced. This pyrite carries, according 
1 According to Kedzie, loc. cit., its mean thickness is 140 feet. 
Bull. 182—01 16 
