PD PD EDWARD B. MATHEWS 
Among the alteration minerals resulting from the weather- 
ing or metamorphism of this type are epidote and sericite 
associated with the feldspar; and calcite, chlorite, and muscovite 
accompanying the biotite. 
47, 
SS 
N 
S 
S 
X 
S 
CE OO 
a, 
x 
77 
LZ 
N NN 5 VV 7 
SS Ef 27 ea 
Pikes Peak Summit Cripple Creek Gneissic Postgranitic 
Fic. 4.—Sketch map showing the distribution of the various types of granite 
occurring in the Pikes Peak quadrangle. 
Distribution.—The granites of this type extend northeastward 
from a sinuous line drawn through the lower slopes of Blue 
Mountain, Dome Rock, Cripple Creek, and Oil Creek Canyon to 
the southeastern border of the Pikes Peak Quadrangle. (Fig. 4) 
The limits beyond the area of the Quadrangle have not been 
