158 THE GRANITES OF MAINE. 
generally twinned, are intergrown with oligoclase and quartz. Some 
have a zonal structure indicated by inclusions of quartz and oligo- 
clase. The oligoclase is partially altered to kaolin and a white mica. 
The quarry is 200 feet from north to south by 50 feet from east to 
west, and averages about 5 feet in depth. 
Rock structure: The sheets, from 1 to 4 feet thick, dip 10° S. 
30° E., and are crossed by joints that strike N. 75° W. and dip 651 
N. and 65° S., forming headings at the south side and one in the 
center. Black knots up to 2 inches across occur here and there; 
also pyrite crystals on the joint faces. 
This stone has been used for monuments and buildings in Belfast 
and for paving blocks, but the quarry has not been in operation for 
five years. The product had to be carted 5 miles to Searsport. 
The Oak Hill quarry is in the town of Swanville, on Oak Hill, 
about 6 miles north-northwest of Belfast. Operator. Oak 1 1 ill Granita : 
Company, Belfast, Me. 
The granite (specimen 49, a) is a biotite granite of slightly bluish I 
dark-gray color and line even-grained texture, with particles ranging 
generally from 0.25 to 1 nun. in diameter and an occasional feldspar 
up to 2.5 mm. or one-tenth inch. It consists, in descending order of 
abundance, of slightly bluish-white potash feldspar (microcline and 
orthoclase), smoky quartz, -lightly bluish-white soda-lime feldspar 
(oligoclase). and black mica (biotite). The feldspars are intergrown 
with quartz and the oligoclase is here and there partially altered to » 
a white mica. The stone takes a wvx fin< polish to the durability of 
which the lineness of the mica contributes. 
The quarry, which was opened about 1s7l\ consists of several!'; 
opening-, the largest of which is 175 by 100 feet, with a working face j 
GO feet high. 
Rock structure: The sheets, from 1 to 4 feet thick, dip 10° W. 
Vertical or steep joints, striking X. *<> ! W., recur at intervals of 10 
and 20 feet, and form heading- on the north side. Sap 2 inches thick 
occurs along the sheets. Knots up to 2 inches in diameter occur 
occasionally. 
There is no machinery at the quarry at present. The only work 
being done is the making of paying blocks at one of the openings. 
Transportation was by cartage one-fourth mile to a siding running.'] 
from Sargent> Crossing on the Maine Central Railroad. 
The product is particularly adapted to monumental uses. The 
stone is the darkest of the fine-textured granites of the State (com- j 
pare Freeport, p. 77; Pownal, p. 7 ( .>; and Sherwood, p. 105) and i^- 
finer textured than the blue Westerly, R. I., granite. This quarrj 
was formerly leased to the New England Granite Company, of 
Westerly. 
