22 
IOWA ACADEMY OF SCIENCES. 
STAGES OF THE DES MOINES, OR CHIEF COAL- 
BEARING SERIES OF KANSAS AND SOUTH- 
WEST MISSOURI AND THEIR EQUIV- 
ALENTS IN IOWA. 
BY CHARLES R. KEYES. 
The principal coal-bearing formation of Iowa and other parts 
of the western interior basin is the lower coal measures, or Des 
Moines series as it is now termed. Although the formation 
has been long recognized in practically its present geologic 
limits it has been only very recently that any attempt has been 
made to even suggest subdivisions of the series. It is to these 
minor distinctive parts that have been made out clearly in 
southwest Missouri and the adjoining portions of Kansas that 
attention is directed. 
Over the whole of its areal extent in the western interior 
coal field the Des Moines series, or productive coal measures, is 
clearly limited above by the Bethany limestone and below by 
the Mississippian limestones, or earlier formations. Until very 
recently no attempt has been made to subdivide the principal 
coal-bearing series of the region. Minor divisions have been 
vaguely recognized, however, in different parts of the area 
occupied by these rocks. In the southwestern extension of the 
belt the most definite information in regard to the detailed rela- 
tions of the various strata has been obtained. In that part of 
western Missouri south of the Missouri river three stages have 
been traced out. They are known to extend northeastward 
into other parts of the state. Since these have been deter- 
mined very similar lines have been recognized in Kansas, where 
special names have been applied.* The three stages that are 
capable of more or less clear demarkation in Missouri and Kan- 
sas are the Cherokee shales, at the bottom, the Henrietta lime- 
stones, and the Pleasanton shales at the top. 
Cherokee Shales . — The term Cherokee as a designation for the 
lower part of the coal measures was first applied by Haworth 
*Univ. Geol. Sur., Kansas, vol. I, p. 150, 1896. 
