IGNEOUS AND CRYSTALLINE ROCKS. 53 
Ba and Sr not looked for. 
L. Altered quartzite. Contains more fibrous chlorite, some sericite, a little kaolin 
and biotite, grains of magnetite, earthy matter, and sometimes a little calcite. Analy- 
sis by R. B. Riggs, record No. 570. P. R. C. 1009. 
M. Mottled quartzite. Analysis by Riggs, record No. 573. P. R. C. 1021. 
N. Purplish slate, containing many small crystals of red feldspar and scales of mica. 
Analyses by J. E. Whitfield, record No. 520. P. R. (. 1024. 
O. Very slightly altered slate. Analysis by Riggs, record No. 576. P. R. ©. 1011. 
Material for analysis dried at 104°-105° 
Ba and Sr not looked for. 
P. Red granitic rock resembling D, but with more dark spots, found in contact with 
the purplish slate, N. Liparose. Consists mainly of red feldspar, quartz, and chlorite. 
Analysis by J. E. Whitfield, record No. 519. Dried at 104°. P. R. ©. 1014. 
Q. Groundmass of red mottled quartzite. Analysis by W. F. Hillebrand, record 
No. 499. P. R. C. 1022. 
R. Green mottlings from Q. Mostly quartz and sericite. Analysis by Hillebrand, 
record No. 498. 
§. Another sample of the green mottlings, selected with especial care. Analysis 
by L. G. Eakins, record No. 1058. 
T. Brilliantly red vitreous quartzite. Analysis by R. B. Riggs, record No, 574. 
Dried at 105° =P. R. Cc; 1008. 
15619—Bull. 419—10——5 
