PETROLOGY OF SOUTH CAROLINA GRANITES 749 
namely, at Smith Branch (County) Quarry near Columbia, the 
Anderson Quarry in Fairfield County, and at the Casparis Quarry 
near Lexington. In the quarry near Columbia, aplite dikes are 
rather numerous, ranging up to four feet in thickness. They are 
uniformly reddish brown in color and so dense and fine-grained in 
texture that the minerals cannot be distinguished by the naked eye. 
The principal minerals, under the microscope, are orthoclase, some 
microcline, oligoclase, quartz, a little biotite, apatite, and secondary 
chlorite and epidote. At the Anderson Quarry in Fairfield County, 
the aplites, ranging in thickness from 1 to 12 inches, are banded with 
Fic. 5.—Bared slope of granite-gneiss at Beverley Quarry, Beverly, Pickens 
County, S. C. 
pegmatite. ‘They are very fine-grained in texture and of light-gray 
color, with scant biotite visible to the unaided eye. The minerals are 
microcline, orthoclase (partly microperthite), some oligoclase, quartz, 
very little biotite, occasional muscovite, zircon, and accessory chlorite 
and epidote. 
Pegmatites—Pegmatites are frequent over the region and at times 
attain considerable size. ‘They are granitic, mineralogically, without 
unusual or rare minerals observed in them, and may cut any of the 
rocks of the crystalline complex. The mica is usually biotite with 
frequently some muscovite associated with it. In the quarry at 
Pacolet black tourmaline is a constituent of some of the pegmatites. 
In Abbeville, Anderson, Greenville, Oconee, and Pickens counties 
the pegmatite dikes vary from 9 to 20 feet in thickness, and, as indi- 
cated in the table of analyses below, the feldspar of these pegmatites 
is the potash variety. 
