lO COLORADO COLLEGE STUDIES. 



and the other in the Cimarron series. Elsewhere in this 

 article, the upper formation is described as the Salt Plain 

 measures; the lower formation, which is the basis of the 

 great salt industr}' of Kansas, is here called the Gciida salt- 

 measures, from the town of Geuda Springs, which is located 

 in the area of its outcrop. 



At a quarry to which the writer was conducted by the 

 favor of Prof. A. W. Jones of Salina, and which is near the 

 right bank of the Smoky Hill river two or three miles 

 S. S. E. of Salina, is an exposure of perhaps about 30 feet 

 of carbonaceous shales and more or less shaly limestones 

 having rather a pronounced westerly dip and including a 

 fossiliferous horizon in which one lamina of rather hard 

 limestone bears numei ous indifferently preserved examples 

 of Myalina permiana and smaller undetermined bivalves. 

 This ledge is apparently but little below the summit of the 

 Geuda and overlies a bed of gypsum, which [fide A, W. J.) 

 outcrops in the bed of the river near by and is also pierced 

 by a shallow shaft in the vicinity of the quarry. Prof. 

 Jones states that the most southerly appearance of these 

 limestones and shales on the Smoky is about four and a 

 half miles south of Salina. He also states that the gypsum 

 at this quarry is supposed to be the same as that which is 

 worked at Gypsum City; but it seems to the writer, from a 

 consideration of the dip of that gypsum between Hope and 

 Gypsum City, that the gypsum south of Salina, which may 

 be called the Greeley gypsum from its occurrence in Greeley 

 township, is higher by not less than a hundred feet than the 

 Hope gypsum., as that at Hope and Gypsum City may be 

 called. 



The lower limit of the Geuda in north-central Kansas 

 is drawn at the summit of the Marion concretionary hme- 

 stone of Prof. Prosser, which the latter seems with good 

 reason to regard as the "first cherty limestone" of Prof. 

 Swallow. 



The Geuda formation is very complex in its com- 



