LN WASHINGTON" COUNTY. 159 
WA SH I N GT( > N < '< » l N TY. 
The quarries in Washington County are in the towns of Addison, 
3aileyville, Calais, Jonesboro, Jonesport, Marshfield, and Millbridge. 
The Pleasant River black-granite quarry is in the town of Addison, 
it Dalotville, on the east side of Pleasant Eiver Bay. Operator, 
Pleasant Eiver Granite Company, Addison, Me. 
This rock (specimen 93, a) is an hypersthene-olivine gabbro of 
ilmost black shade and of medium ophitic texture, with black par- 
deles up to half an inch and slender whitish crystals. The polished 
surface is jet-black mottled with a little white. Under the micro- 
scope this rock consists, in descending order of abundance of slender 
A'hitish transparent crystals of a feldspar (with both lime and 
pda, andesine-labradorite) intricately interlaced, the spaces between 
which are filled with a dark-brownish diallage (see p. 57), black mica 
(biotite) , a little hypersthene, and greenish olivine, together with 
secondarv magnetite, a white mica, and calcite. The diallage is 
dtered along its edges to hornblende. The stone takes a very fine 
jolish, and the hammered or cut surface is almost white. It is 
eferred to by George P. Merrill a and by John E. Wolff. 6 It was 
eported to the company by John S. Newberry in October, 1800, as 
withstanding a pressure of 22,410 pounds per square inch. Its 
weight is given by the firm as 184 pounds to the cubic foot. r 
The quarry, opened about 1885, measures 75 by 50 feet and has 
i working face about 50 feet high. It is on the south side of a ridge 
JO feet high, extending east-west, the upper 5 to 10 feet of which con- 
ist of morainal sand and bowlders. (See PL X, J.) 
Rock structure: The sheets, from 3 to 17 feet thick, undulate from 
;he horizontal to a dip of 10° E. Vertical joints, striking N. 80° E., 
^ecur at intervals of 5 to 10 feet and form a heading on the south ; a 
set, striking N. 35° W., recurs at intervals of 20 to 30 feet, forming a 
leading on the west. There are also several irregular fractures. 
The rift is vertical east-west, and the grain is horizontal. There are 
10 feet of stained and fractured rock at the top, but sap is usually 
lardly an inch in thickness. Dikes of whitish quartz monzonite, 
pescribed in detail on page 01, measure from 1 to 14 inches in thick- 
ness. There is also a more or less horizontal light and dark band- 
ing, due to alternating changes in the amount of feldspar. This is 
shown in PI. X, A, as are also the dikes, sheets, joints, and one of 
he headings. 
The plant consists of 3 derricks and 2 hoisting engines, 1 steam 
Irill, 1 compressor, 2 pneumatic hand tools, 2 polishers, 1 polishing 
a Tenth Census, vol. 10, 1884, p. 24. 
» Ibid., p. 11G. 
'' Professor Newberry's report will be found in the Eighteenth Ann. Rept. U. S. Geol. 
Survey, pt. 5, continued, 1897, p. 961. 
