1 I) 
THE GRANITES OF MAINE. 
The quarry, opened about 1885, measures 400 feet from north- 
northwest to south-southeast by 250 feet across, and has an average 
depth of 30 feet. There is no drainage problem. Stripping up to 
4 feet thick. 
Rock structure: There is a vertical northeast-southwest flow struc- 
ture indicated by the dividing line between the dark and light 
granite (shown in diagram sketch of upper part of quarry, fig. 32), 
and also in the light and dark banding of some of the lower sheets. 
The sheets, from 2 inches to 1<> feet thick, dip about 5° E. In the 
south part of the quarry they measure up to 2 feet only, but in the 
northern part from 2 feet to 16 feet. Joint and dike courses are 
shown in fig. 33. A recur- at intervals of 200 feet. From the rela- 
tion of the thickness of the -beets to the joint spaces, both in this 
quarry, as shown in fig. 32, and in two adjacent abandoned openings, 
known as the "Mink Hole"' and " Bank quarry," it appears that in ; 
Fig. 32. Diagram sketch showing junction of light and medium gray granites (quartz 
monzonites) and the lateral change in thickness of sheets at the Dodlin quarry, near 
Norridgewock. 
places thin sheets, in other- thick -heel-, continue downward in alter- 
nating vertical zone.-, and that thin -beets are also apt to occur on 
both sides of the vertical joints for a few feet. These relations, which 
are very exceptional in the .Maine quarries, may be due to vertical 
faulting. A horizontal displacement (if a foot in a vertical flow- 
structure band was detected in the working face, evidently dtie tc 
faulting at right angles to that just referred to. The rift is hori- 
zontal — that is, at right angles to the flow structure. The grain is i 
vertical with course X. L5 E., parallel to the jointing. The north- 
south pegmatite dike, up to 1 inches thick, dips 20° S. : the other if 
vertical and an inch thick. They are garnetiferous. Sap G inches 
thick occurs at the top and bottom of sheets, and "shakes'' occui 
along the sheets near headings. (See p. 40.) Knots, both dark an( 
white, occur but rarely. 
The plant consists of 10 derricks. 3 hoisting engines, and 3 steal) i 
drills. 
