THE PERMIAN SVSTKM IN KANSAS. I5 



shale and the number and thickness of the rock-salt beds 

 increase with distance from the outcrop. 



In strata of shale associated with some of the principal 

 beds of rock-salt, occur iron-red pseudomorphs of halite 

 after selenite. 



In the deep-lying part of the formation, remote from 

 the outcrop, the greatest known thickness of these salt-meas- 

 ures is 420 feet, which was obtained in a boring at Anthon}-. 

 The thickness of the outcrops probably varies from 300 to 

 400 feet. 



The dip of the Geuda measures in southern Kansas is 

 southward and westward; in northern Kansas, it appears 

 from various observations to be northward and westward. 

 From these data it may be inferred that the salt has the form 

 of an anticlinal whose summit-line dips nearly westward. It 

 seems probable that Arlington is located somewhere nearly 

 over the crest of this anticlinal, since the salt-beds de- 

 cline in either direction (northward and southward) from 

 their position beneath that town. The northward descent 

 is, however, small as compared with that to the southward. 

 Thus, at Arlington, the summit of the salt-beds is 

 reached at an elevation of approximately 910 feet above 

 sea-level,whence it descends (^gradually, as shown by the Ster- 

 ling and Lyons drillings) to about 815 feet above sea-level 

 at Ellsworth and to only about 383 feet above sea-level at 

 Anthony. 



The name here i»iven to this formation is one that has 

 been applied to it in the writer's manuscripts for many 

 months. In a reccent article,* Professor Prosser has called 

 nearly the same formation "the Marion formation;" but 

 aside from the fact that he includes in such formation a 

 zone of "variously colored shales and marls" which is 

 above the zone of gypsum-horizons, and therefore belongs 

 to the lower Wellington, the name, Marion, as a strati- 

 graphic term, is preoccupied, having been previously es- 



*Loc. cit., p. 78G. 



