70 
Journal of the Mitchell Society 
[ November 
terizing much of the Piedmont Plateau region. The Roan gneiss 
leaves a greenish sandy soil on disintegration, and an ocher-yellow 
to dark reddish brown or chocolate-colored clayey soil on deconr 
position. Black stains of manganese are associated with many of 
the soils derived from hornblendic rocks. 
A clew to the nature of the rock formations in a given region is 
often furnished by the character of the gravels in the bottom 
lands and streams draining that region. Thus in this area a very 
light colored gravel with much quartz debris indicates a granite or 
its contact or a very highly pegmatized country rock. Garnets and 
hematite iron ore, with which blocks of mica or cyanite gneiss are 
associated, indicate Carolina gneiss. Quantities of black sands in 
the stream gravels, containing magnetite, ilmenite, hornblende, 
etc., are characteristic of the Roan gneiss. 
Occurrence 
Monazite has been found in several varieties of rocks, in the 
soils derived from monazite bearing formations, and in gravel beds 
formed through the erosion of these formations. Only gravel 
deposits have been profitably worked for monazite on an extensive 
scale, though in some places the surface soils adjoining rich 
deposits of monazite, or the saprolite or rotted rock underlying 
them, are found to be sufficiently rich in monazite to be sluiced 
down and washed. 
The percentage of monazite in both the original rock matrix and 
in the gravel deposits is small, and probably does not often run 
over 1 per cent. Figures are not available for the percentage of 
monazite in gravel deposits. From the saprolite underlying the 
F. K. McCurd mine, three-fourths of a mile northeast of Carpen- 
ter Knob, N. C., Mr. George L. English obtained about one-third 
of a pound of monazite per ton, or about 0.016 per cent. At the 
British Monazite mine, 3 miles northeast of Shelby, N. C., the 
quantity of monazite in the hard rock formations was found by 
Mr. Hugh Stewart, engineer in charge, to run from between 0.03 
per cent and less up to over 1.10 per cent. 
