jollier.] AURIFEROUS VEINS ON UNALASKA [SLAND. 103 
QUARTZ VEINS. 
South of Dutch Harbor for several miles the rocks arc cut by a 
>ystem of nearly vertical joint planes which extend approximately 
iast and west. Mineralization has occurred along these joints, and in 
ome instances quartz veins have been formed. Several such quartz 
reins are exposed in the bluff west of Unalaska, where they have been 
prospected by short tunnels. The best example, however, is found at 
he gold mine located 1£ miles south of Unalaska and about a quarter 
>f a mile from the shore of Captains Bay, where a number of small 
Aeins of this kind are contained in compact gray andesite. The largest 
)f these forms the main ore body of the mine and has been opened for 
ibout 200 feet. It has a maximum width of 6 or 7 feet, but thins out 
n both directions fiom the widest part and at the ends of the tunnels 
s not over 1 or 2 feet wide. The samples obtained here consist of 
vaolin and cellular quartz, heavily stained with iron in the form of 
imonite. Samples obtained on the dump and around the mill indicate 
/hat a considerable portion of the ore originally contained unweathered 
Dyrite and other sulphide minerals. A sample taken by the writer 
Tom the face of the drift at the principal ore body was assayed by 
S, E. Burlingame & Co., of Denver, who report .02 ounce of gold to 
he ton and a trace of silver. It is reported that before the mill was 
milt assays promised very high values, which were not realized from 
ihe ore when milled. 
DEVELOPMENT. 
The main tunnel runs east from the entrance about 20 feet, then 
urns south, crosscutting the joint system. The principal ore body of 
he mine, which is developed by short drifts, is crosscut about 50 feet 
rom this turn, but the tunnel is continued southward about 100 feet 
arther to a well-defined but apparently little mineralized joint run- 
ling east and west, which it follows east for several hundred feet. At 
ihe end of this distance there is a crosscut to the north which prob- 
ibly falls a little short of reaching the line of the extension of the 
nain ore body. A few prospectors were on the ground in 1904, pre- 
paring to resume work in the mine with a view to determining (he 
xtension of the main ore body. 
