LODE MINING IN SOUTHEASTERN ALASKA. 69 
SKOWL ARM. 
During 1906 the Kiam mine, on Skowl Arm, and the adjoining 
Mammoth and Lake View groups to the east were idle. The smelter 
returns from a large shipment of the ore were not satisfactory, and its 
high content of sulphur made it an undesirable smelting product. 
After a careful examination made of these properties this last summer 
the owners decided to discontinue operations at this point. 
The ore bodies which have been developed are heavily mineralized 
masses of pyrite and pyrrhotite ore containing chalcopyrite and 
occurring in a schist country rock. These masses coincide in trend 
and dip with the rock structure. At the Kiam mine the mineralized 
band is continuous over a length of possibly a thousand feet and has 
an average width of 20 feet, though in places it is 60 feet wide. In 
depth, however, the deposit was not undercut by the tunnels cross- 
cutting the ore-bearing zone, and it appears to be limited to some 
tens of feet from the surface at the point where it has been developed 
by the Powell tunnel. The tonnage of available ore is therefore rela- 
tively small, and though it could be readily mined its value is reported 
as insufficient for profitable extraction. 
The Mammoth and Lake View groups are clearly in the general line 
of strike with the Kiam ore bodies, and so far as developed the deposits 
are of the same character. They appear to be merely smaller and 
weaker examples of the Kiam type. 
NORTH ARM. 
At the head of North Arm locations were made in 1905 on copper- 
bearing veins about a mile from tide water and less than a hundred 
feet in elevation. Early in 1906 these were transferred to the Cymru 
Mining Company, which immediately began operations and the 1st of 
October began shipments. 
The veins, four of which have been exposed, lie in the limestone 
and greenstone-schist country rock and strike N. 35° W., nearly par- 
allel to its structure, dipping 70° SE. They vary in width from 1 to 
5 feet and contain chalcopyrite and pyrite scattered through a quartz 
gangue. Near the surface the ore is changed to the oxides and car- 
bonates of iron and copper. A shaft 105 feet deep has been sunk on 
the larger of these veins and at the 100-foot level a drift extended. 
A large percentage of the ore mined was from a surface trench 500 
feet long and 4 to 8 feet wide, following the vein. From these work- 
ings a surface tram leads to ore bunkers, from which the product is 
loaded directly into hulks or barges for shipment. 
