QUARKIES IN KNOX COUNTY. 
125 
ind dike courses are shown in fig. 23. A recurs frequently on the 
lorth side of the quarry, but two joints are 50 feet apart and have 
rreatly facilitated the opening of the quarry. B dips 70° N., travers- 
ug the entire quarry. The rift is vertical with a N. 00° E. course. 
vnots and dikes occur. Sap is 3 inches thick on the sheet surfaces. 
The plant consists of 4 derricks, operated by 4 engines ; 1 compres- 
:or, with a capacity of 527 cubic feet of air per minute; 2 steam 
lrills; 3 surfacers. Pneumatic drills and tools were about to be 
idded. 
Transportation is effected by cartage 300 feet to wharf. 
The quarry was idle in July, 1905, but preparations were being 
nade for resuming work. 
The product, consisting chiefly of building stone and some random 
ind paving blocks, finds a market mostly in the West and South. 
Specimen buildings, etc.: Carnegie 'Library at Alleghany, Pa.; the 
Fig. 23.— Structure at Sprucehead quarry, Si. ( 
lew post-office and custom-house at Atlanta, Ga.; the columns of the 
Auditorium building, Chicago, 111. ; the Mutual Life Insurance Com- 
pany's building, New York. 
The Clark Island quarry is on Clark Island, in the town of St. 
jreorge, about 12 miles south-southwest of Rockland. Operator, John 
0. Rodgers; office, 11)09 Amsterdam avenue, New York. 
The granite (specimen 12, a) is a biotite-muscovite granite of 
)luish, medium-gray color and of fine to medium even-grained tex- 
ture, with feldspar up to one-fourth inch and mica under one-tenth 
nch. It consists, in descending order of abundance, of light-bluish 
potash feldspar (microcline and orthoclase), clear or very slightly 
;moky quartz, light-bluish Soda-lime feldspar (oligoclase), black mica 
(biotite), and white mica (muscovite), together with accessory gar- 
met, zircon, apatite, and secondary chlorite. The oligoclase is partly 
