&NSOME.] SILVER LAKE MINE. 149 
Although the lodes of the Silver Lake Basin have been classified in 
3W0 groups, it should be borne in mind that the distinctions upon 
Erich the grouping is based are quantitative rather than qualitative. 
Die difference in direction, sufficiently marked and definite on the 
ivest side of the lake, becomes less so on the east side, where the Silver 
Lake lode appears to begin splitting up into its ultimate ramifications. 
Moreover, as will appear when the separate mines are described, the 
Kneral difference in the ores of the two groups is a difference in value 
Kther than in mineralogical type, and is neither constant nor without 
exceptions. 
It is fairly certain that the original formation of the fissures of Sil- 
ver Lake Basin was unaccompanied by any considerable faulting. A 
Breful study of all the available underground workings and of the 
mrface geology and topography of the basin has failed to reveal the 
sxistence of any extensive tangential movement (faulting) along the 
Bin fissures. Moreover, if the mutual relationship of the lodes has 
>een correctly interpreted, it would seem that the conception, very com- 
nonly held, that vein-filled fissures are produced essential^ by fault- 
ng involving considerable tangential movement, and usually by thrust 
aults, is inapplicable as an explanation in the present case. The 
•Qore general aspects of this subject are discussed under the head of 
'The lode fissures," on pages l.;-<'>.'). 
pilver Lake mine. — This, the most extensively developed mine 
fchin the quadrangle, is situated at an altitude of about 12,300 feet, 
Wth its principal adit near the western edge of Silver Lake. As is 
requently the ease, it includes a number of individual claims, some 
f which, such as the Whale, were separately worked in former days 
nd produced considerable ore. Prior to 1881, the Whale, Silver Lake, 
'found .Mountain, and other claims now embraced in the Silver Lake 
line had attracted but slight attention. In 1882 a little ore was pro- 
uced, which is said to have carried 50 ounces of silver and 60 per 
:;ent of lead. In 1883, 72 tons of ore, containing 28 ounces of silver per 
Ion and 55 per cent of lead, were shipped to Sweet's Sampling Works in 
: ilverton, and the Silver Lake claim, with its 55 feet of drifting, was 
i ?garded as a promising prospect. Since then its development has 
I regressed with rapid strides. In 1801 the mine was credited in the 
I tint reports with a product of $254,908. 
At least six distinct lodes have been worked, and the vertical dis- 
t ince from the uppermost to the lowermost stopes is somewhat over 
1 000 feet. The main adit is a crosscut for about 250 feet. It then 
i )llows the Silver Lake lode northwesterly for about 1,000 feet. 
p hence a crosscut to the southwest, some 900 feet in length, gives 
b'2cess to the various lodes of the second group, viz, the L. A. S., 
i . G. S., Royal, Stelzner, and New York City lodes. A northwesterly 
- rift along the New York City lode for about 1,250 feet again comes 
i ito the Silver Lake lode, and from this junction a drift of about -400 
f 'et runs out to the surface in Whale Basin, on the west side of 
