QUARRIES IN WASHINGTON COUNTY. 161 
brownish diallage (partially altered to hornblende), black mica (bio- 
tite), a little hypersthene, and quartz, together with accessory mag- 
netite. This rock turns a little brownish on continued exposure and 
weathers spheroidally. A polished block, reported as from this 
quarry and shown to the writer in a stonecutter's yard at Quincy, 
Mass., had become pitted from exposure. 
The quarry, opened in 1883 and abandoned in 1902, is 200 feet 
square and from 10 to 20 feet deep. It has a track 300 feet long to 
a wharf which admits schooners of 11 feet draft. Although the rock 
has been here worked down to sea level, there is, a few hundred feet 
east, on the property of William N. Carver, a rising ridge of the 
same rock which is as yet untouched. 
Rock structure and variations: The sheets, from 3 to 8 feet thick, 
are horizontal or dip 20° N. Vertical joints, striking N. 80° E., recur 
at intervals of 5 to 20 feet, and a set, striking N. 30° W., recurs at 
intervals of 2 to 10 feet. There is rarely a set striking N. 45°-50° W. 
A 1-inch dike of pegmatite strikes N. 30° W. 
The Hall black-granite quarry is in the town of Baileyville, at the 
north edge of Meddybemps Lake, 5 miles southwest of Baring, on 
Washington County Railroad, about 7 miles southwest of Calais. 
Operator, F. H. Hall, Calais, Me. 
The rock (specimens 98, b, d) is a norite of brilliant luster, very 
dark gray shade (without any yellowish tinge), and of coarse texture 
and marked rift, with jet-black particles up to one-half inch in diam- 
eter in a network of translucent whitish feldspar. Under the micro- 
scope it consists, in descending order of abundance, of elongated trans- 
parent crystals of feldspars (with both soda and lime, andesine-labra- 
dorite) interlaced, but parallel in the flow and rift direction, with 
the intervening spaces filled with hypersthene (partially altered to 
brown hornblende), magnetite, and black mica (biotite), together 
with accessory calcite and a white mica derived from the partial 
^alteration of a few of the feldspars. The hypersthene and horn- 
blende constitute the conspicuous black particles seen with the un- 
aided eye. In the lighter bands of the rock the feldspar largely 
crowds out the hypersthene. The content of magnetite is so great that 
I large blocks of the rock deflect the magnetic needle. Mr. Hall states 
'that the stone endures the fire and water test very well; that its com- 
Jpressive strength, as determined by the Watertown Arsenal testing 
I machine, is 22,500 pounds to the square inch, and that an assay by 
Carmichael, of Boston, shows it to contain a small percentage of gold. 
'The papers giving formal evidence of these results having, unfortu- 
nately, been misplaced, can not be cited here. The stone takes a high 
i polish and the hammered and cut surface is almost white. It is very 
i 1 tough, but splits with facility along the rift. 
3495— Bull. 313—07 11 
