206 OC. A. White—Glacial Drift in the Upper Missouri. 
Art. XXIL.—Glacial Drift in the Upper Missouri River Region ; 
by CHARLES A. WHITE. 
[Published in advance by permission of the Director of the U. S. Geological 
Survey.] 
bowlders and coarse gravel, without clays. It was ound 
nowhere abundant, and over a large part of the space within - 
syenitic, some showing no lamination, some showing It 10 18 
tinctly, and some being schistose ; and the proportions of feld- 
spar, quartz and hornblende, varying much in different spect 
mens. Among these bowlders of Archean rocks are frequent 
masses of cream-colored magnesian limestone containing 1g" 
ments of fossils, which I regard as belonging to the Galeua 
division of the Trenton limestone. 
This glacial drift material is very different from the coarse 
drift gravel which is so abundant in the valley of the Yellow- 
stone, and which has doubtless been derived from the mountain 
region about its sources. The latter is similar to that which !§ 
usually found in the valleys of rivers which have their rise 10 
the Rocky Mountains. 
