22 COLORADO COLLEGE STUDIES. 



As local saline impregnations occur to some extent in 

 most of the terranes of the Kansas-Oklahoma Permian, 

 it is possible that it may not always be easy to distinguish 

 the limits of the Salt Plain measures; but the salt-zone 

 which is here especially designated as the Salt Plain meas- 

 ures is of considerable extent and is that from which is de- 

 rived the salt of the Salt plain of the Cimarron river 

 (called often the Great Salt plain), which is the saline usually 

 referred to in the literature of this region wlien the un- 

 quahfied expression, "the Salt plain," is employed. 



The stratigraphic position of this salt-zone may be 

 seen in Kansas on the east slope of the Cedar hills of 

 Harper county and on the south side of the Salt fork, a 

 few miles below ^^tna, where, in each case, beginning 

 immediately below the bright red Cedar Hills sand- 

 stones, are the saliferous clay-shales which are the source of 

 the salt that at the one locality gives character and name to 

 the Little Salt creek that traverses adjoining parts of Barber 

 and Harper counties, and at the other has given rise to 

 one of the peculiar fiats, or base-levels, so frequent in salt- 

 shale topography, and which are evidently produced 

 through the agency of the salt itself. Little Salt creek, 

 though having the highest source of its salt in a horizon of 

 saline impregnation immediately below the base of the Cedar 

 Hills sandstones, apparently cuts other saline horizons 

 at somewhat lower levels, and its lower portion may inter- 

 graduate with and be only arbitrarily separable from the 

 upper of the Harper sandstones. 



At Pratt, salt deposits were encountered a few years 

 since, in drilling, without first passing through any thick 

 body of gray shales like the Wellington; and the relation of 

 these to not far distant outcrops of the Cimarron series and 

 to sea-level, indicates that they belong to the upper, cr Salt 

 Plain, measures. 



The following is a condensed record of the boring at 

 Pratt : 



