298 The American Geologist. May, isgy 
line denudation. An answer might perhaps be arrived at by 
studying its boundary in the direction of the lofty pointed 
mountain chain that hems in this district north of the Klondike 
river. The geology and topography of these projecting 
mountain-chains, the glacial phenomena and the shore-lines 
that may exist there, are some of the most important problems 
requiring investigation in this otherwise extremely interesting 
district, which is likely to attract a large share of attention from 
geologists in the immediate future. 
THE MISSOURIAN SERIES OF THE 
CARBONIFEROUS. 
By Charles R. Keyes, Des Moines. Iowa. 
Introductory. 
The Carboniferous rocks of the Missouri River region were 
brought to notice more than half a century ago. A generation 
ago they were the subject of one of the most bitter controver- 
sies that ever occurred in the history of American geology. 
For a period of two decades all geological consideration of the 
region has been neglected. Only of late has interest in it re- 
vived. 
The almost total lack, from the very beginning, of exact 
and connected data relating to the geology of the Missouri 
river has necessitated recently a reconsideration of the whole 
subject. The result has been to gain a complete and connected 
idea of the succession of formations, and an arrangement of 
them that is eminently satisfactory as well as readily applicable 
to the whole region. This district comprises large portions of 
southeastern Nebraska, southwestern Iowa, northwestern 
Missouri, eastern Kansas, Indian Territory and eastern Okla- 
homa. 
The term Missourian was originally proposed'^ for the 
major part of the great sequence of limestones and shales, that 
has long been known, in the western part of the Mississippi 
valley especially, as the "upper coal measures." Subsequently! 
*Iowa Geol. Surv., Vol. II, p. 85. 1893. 
t American Geologist, Vol. XVIII, p. 25, 1896. 
