WRIGHT 
WRIGHT 
* ND ] DEVELOPMENTS IN SOUTHEASTERN ALASKA. 57 
beds of impure coal and tuff. The average total thickness of coal 
is about 5 feet. It has been developed by a crosscut tunnel 2.'><> feet 
in length and a drift of 100 feet along the coal bed. From the drift 
an incline shaft at an angle of 25° has been sunk to a depth of 180 
feet, where the coal bed, found to be displaced, was again discovered 
after much drifting. 
Other coal seams, of no economic importance, however, occur both 
at Hamilton Ba}^ and at Port Camden in Keku Straits south of 
Admiralty Island. 
The coal in the Alexander Archipelago gives no promise of being in 
sufficient quantity to make producing mines and thus reduce the cost 
of fuel. Small amounts, however, may be obtained from some of the 
coal seams for local use. 
SITKA MINING DISTRICT. 
The Sitka mining district includes both Baranof and Chichagof 
islands, the two westernmost islands of the Alexander Archipelago. 
The rocks strike in a northwest direction, usually have steep dips, and 
are arranged in wide belts. The eastern coast of Chichagof Island is 
composed of limestone beds of Carboniferous age, into which have 
been intruded bands of granodiorite, with their long axis parallel to 
the cleavage of the sediments. At the south end of the island is a 
series of chlorite-schists and carbonaceous shales which appear not only 
to underlie Hooniah Sound, but also to form the country rock in the 
vicinity of the Rodman Bay mines. Along the narrows of Peril 
Straits is a wide belt of granodiorite which farther southwest shows 
such segregation of the basic minerals as to resemble greenstone. 
Adjacent to this is an assemblage of sedimentary rocks metamorphosed 
to mica-schists and overlain by slate-gra}^wacke series. In the vicinity 
of Sitka these strata form the bed rock exposed along the coast and 
the countiy rocks of the ore deposits. This slate-gra}^wacke series has 
been intruded by numerous dikes of varying composition which are 
associated with or near the mineral deposits. 
The ore bodies are irregular, quartz-tilled fissures, and are usually 
parallel to the bedding planes of the slate-graywacke country rock. 
The ledges vary rapidly in width and arc divided into a number of small 
veins in some places and into a series of small stringers along the bed- 
iding planes at others, thus forming a mineral zone composed of stringer 
leads. The ledges are crosscut by horizontal veins which are appar- 
ent^ unmineralized and of later origin. The values are essentially 
£old associated with pyrite and pyrrhotite. 
Cache mime. — This property, formerly known as the Stewart mine, 
s located east of and \\ miles from the head of Silver Bay at an ele- 
vation of 720 feet. It is the only patented claim in this area. The 
nine is on a quartz ledge which is 4 to 12 feet in width and strikes 
