56 ALASKAN MINERAL RESOURCES IN 1905. 
PRINCE OF WALES ISLAND. 
Three mining companies the Alaska Marble Company, the El Capitan Marble Com- 
pany, and the American Coral Marble Company — are developing extensive marble deposits 
on this island. 
The properties of the Alaska Marble Company are at the north end of the island and extend 
1 miles north from Shakan village. They lie in a wide marble belt, probably of Devonian 
age, near the contact of a granite mass which forms the low mountains to the east. Dikes 
of diabase, though rare, were noted intersecting the marble. Both fractures and joints are 
present in the marble exposures, though in the quarry extending 20 feet below the surface 
these are less frequent and will not interfere materially with quarrying. The deposit has 
been thoroughly tested at various points by 18 drill holes, sunk to depths of 20 to 80 feet, 
from many of which a marble of excellent quality was obtained. The marble is of a mod- 
erately line granular texture and in color varies from bluish to pure white. Analysis shows 
99.26 per cent of calcium carbonate and 0.3 per cent of magnesia. No injurious impurities 
are present and the material is readily quarried. 
The principal workings are at an altitude of 100 feet above sea level, on the south side of 
Marble Creek, 3,200 feet from the end of a wharf at deep water. An area L00 by 200 feel 
has been stripped of vegetation and a cut with a 20-foot face has been excavated. Der- 
ricks and marble-cutting machinery have been installed and were in operation preparatory 
to the making of a large shipment. Blocks by 6 by 1 feel and approximately 11 tons in 
weight are to be quarried and shipped to Puget Sound, where the marble will be prepared 
for the market. 
The El Capitan Marble Company began operations early in 1904 on a group of claims 
located on a cove on the north side of Klawak Passage, miles from Shakan village. The 
marble deposit borders the east contact of a granite mass represented on the geologic map 
(PI. XI), and from its relative position and similarity to the deposit of the Alaska Marble 
Company can be correlated with it. 
At the quarry, situated close to the water, many joints and fractures were present in the 
surface stone, though from the pit 15 feet below the surface large flawless blocks had been 
extracted. The marble has a moderately line granular texture, is of a bluish-white color, 
and is easily quarried. 
During 190 1 a marble-sawing plant was erected, channeling and gadding machines were 
installed, and 15 tons of marble were mined. This product was cut into slabs from 1 to 4 
inches thick and 4 to 6 feet wide and shipped to Seattle to be polished and prepared for 
market. Proper transportation facilities are lacking, and before large shipments can be 
profitably made a wharf must be built and more extensive excavations made. 
The American Coral Marble Company owns a group of claims near t he head of North Arm, 
a narrow inlet on the east coast of Prince of Wales Island. The surrounding rock beds are! 
largely of banded marble interstratified with chlorite and serpentine schists, all of which 
strike N. 65° W. and dip 85° SYV. A few miles to the northwest a granite mass intrudes 
these beds. The limits of the deposit have not been determined and where exposed, in the 
open cuts and short tunnel driven on the property, the marble was much fractured and 
variable in color. 
The joints or fracture planes were probably formed during the period of tilting or folding 
of the beds and existed before erosion exposed the present surface outcrops. Since that 
time weathering has accentuated and to some extent increased in number the fracture 
planes, and it seems probable that in depth these may, although potentially present as lines 
of weakness, become less frequent and not interfere greatly in quarrying. 
While some part- ^\' the deposit consisted of a pure white, fine-grained marble of excellent 
quality other portions were poorly colored, coarse grained, and of little commercial value. 
The better grade gave the following analysis: Calcium carbonate. 91 per cent : alumina. 3.S 
per cent; silica, 1.4 per cent; magnesia, 0.7 per cent. Pyrite in disseminated particles was 
observed in some of the marble. 
