PERMO-CARBONIFEROUS CONDITIONS VERSUS 
PERMO-CARBONIFEROUS TIME 
1, Cz (CANSIS, 
University of Michigan 
Although the “red beds”’ of the late Paleozoic and other de- 
posits of equivalent age have long been called Permian in North 
America, evidence is steadily accumulating to show that the 
true Permian is absent or nearly so, in the United States, and that 
the beds formerly so called are better regarded as of Permo- 
Carboniferous age. 
Under one or the other of these names there have been included © 
in the eastern part of the United States all the Paleozoic deposits 
above the base of the Dunkard formation in Pennsylvania, West 
Virginia, and Ohio, and possibly the upper beds of the Boston and 
Narragansett basins, the Paleozoic deposits of Nova Scotia and 
New Brunswick above the base of the New Glasgow conglomerate, 
and practically all of the red deposits of Prince Edward Island. 
In the western part of the United States the same horizon is 
believed to begin with the base of the Elmdale formation of Kansas 
and its equivalents, both east and west of the Rocky Mountains. 
The discovery of vertebrate fossils belonging to identical or 
closely related genera and the evidence of fossil piants have led 
to the suggested correlation of the red beds of Kansas, Oklahoma, 
Texas, and New Mexico with the Dunkard of Ohio and Pennsyl- 
vania, and the isolated deposits carrying vertebrate fossils near 
Danville, in Vermilion County, Illinois. Such suggestions of corre- 
lation, however, do violence to the probabilities indicated by the 
stratigraphic position of the beds in which the fossils are found. 
It is the purpose of this paper to point out what seems to be a more 
rational method of correlation, which will reconcile the evidence 
from fossils with that from the stratigraphy. 
Correlation of widely separated horizons must be largely 
accomplished upon the evidence furnished by fossils, but, as is 
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