NONMETALLIC DEPOSITS OF SOUTHEASTERN ALASKA. 57 
During the last summer a wharf, connected with the quarry by a i ramway, was completed, 
adequate buildings were erected, and much machinery installed. It is proposed to ship the 
product in large blocks to Puget Sound, there to be polished preparatory for the market. 
At Dolomi, just north of the entrance to North Arm, this company has located a second 
group of claims on a marble belt. Its quality, however, is said to be inferior to (he above- 
described deposit and has not encouraged extensive development . 
REVILLAGIGELO ISLAND. 
A wide belt of marble exposed in cliffs near tide water was discovered last summer on the 
north side of George Inlet and was located as the Bawden group. The deposit lies in the 
schist-argillite belt adjacent to the Coast Range granite. It is made up of beds of massive 
marble 10 to 20 feet in width, separated by strata of calcareous schist striking northwest 
and dipping northeast. The marble exposed is of good quality and relatively free from 
fractures and joints. This deposit has not yet been developed. 
The George Inlet marble belt extends in a southeasterly direction into Carroll Inlet. 
Here also locations have been made in previous years, but no developments have followed, 
and the value of the marble is not known. 
HAM ISLAND. 
Ham Island lies at the junction of Blake Channel and Bradfield Canal, 25 miles southeast 
of Wrangell. It is about a mile long and half a mile wide, and consists largely of massive 
marble with interstratified beds of calcareous schist striking N. 35° W. and dipping 75° NE. 
Intrusive dikes of basalt are common, while across the narrow channel on the mainland and 
on Wrangell Island wide belts of granite occur in the marble areas and have probably 
induced the present crystalline texture in the marble. 
Two distinct varieties of marble are found — one fine grained and pure white, the other 
very coarse grained and of a pale-blue color. Several systems of jointing planes traverse 
the deposits, but the joints are widely separated and will not interfere greatly in qrarrying. 
Checks or surface cracks are practically absent and wide areas of massive marble have been 
found directly underneath the soil. Much of the marble appears to be free from impurities. 
The Woodbridge-Lowery group of claims lies on the west side of Ham Island and the Miller 
group on the east side. Considerable exploration work has been done by the owners of each 
group and some marble has been quarried for local use. The properties are favorably 
located both for quarrying and transportation. 
LIMESTONE. 
Limestone is abundant among the sedimentary rocks of southeastern Alaska. Belts 
miles in width^ are exposed, and the rock can be quarried at a slight cost. The market 
value of this crude rock, however, at Seattle or San Francisco, is less than the present cost of 
transportation from Alaska to these cities and it is therefore of value only to local con- 
sumers. 
GRANITE. 
Observations on the granite of southeastern Alaska have been confined to examination 
of natural exposures of the rock and of its appearance under the microscrope. No physical 
tests have been made to determine the strength and durability of the stone. 
The main granite belt of the Coast Range varies from 40 to 80 miles in width and, though 
considerably sheared along its contact and interrupted by occasional narrow bands of schist 
contains wide areas of massive rock which would apparently make excellent building stone. 
In addition to the Coast Range belt isolated stocks or masses of granite, often miles in width, 
form the backbone of many of the islands and border the mainland. The central portions 
of these granite masses are comparatively uniform in composition and size of grain, whereas 
near their contacts with the intruded rock beds they are often segregated into acidic and 
basic masses and cut by aplite and pegmatite dikes. 
