LOCATION AND DIVISIONS. 229 



No reference is made to the origin of any of the deposits. The geological 

 literature of Kansas contains numerous other short references to the 

 gypsum deposits, but only the more important descriptions have been 

 noted in this paper. 



Location and Divisions of the Deposits. 



The Kansas gypsum deposits of economic value form a belt trending 

 northeast and southwest across the state. The belt of exposed rock varies 

 in width from 5 miles at the north to 14 miles in the central part and to 

 36 miles near the southern line, with a length of 230 miles. This area is 

 naturally divided into three districts, which, from the important centers of 

 manufacture, are named : The northern or Blue Rapids area in Marshall 

 county ; the central or Gypsum City area in Dickinson and Saline coun- 

 ties, and the southern or Medicine Lodge area in Barber and Comanche 

 counties. These areas appear to be separate, but careful mapping shows 

 a number of isolated intermediate deposits, which serve to connect the 

 northern and central areas. These connecting links are found near Ran- 

 dolph and in the reservoir excavation at Manhattan in Riley county; at 

 Longford, in the southern part of Clay county, and near Manchester, in 

 the northern part of Dickinson county. 



Gypsum deposits of economic importance are reported from near Pea- 

 body, in Marion county, while they appear to be absent through Reno, 

 Sedgwick, and Kingman counties, where the extensive salt deposits occur. 

 There is thus a break between the central and southern areas, which is 

 occupied by salt deposits. 



From an examination of a map of west central United States, with the 

 gypsum deposits indicated thereon, it will be seen that if the northeast 

 line of the Kansas deposits is extended it will strike the Fort Dodge 

 area in Iowa, and if it is continued to the southwest it will strike the 

 extensive deposits of the Canadian river in Indian territory and those 

 of Texas. 



Topography. 



northern area. 



The phrase " low monotonous prairies of Kansas " has no application 

 to the gypsum belt, for there this feature is entirely absent. The north- 

 ern area shows the remnant of a plateau of 1,250 feet elevation, which is 

 now so indented by the Big Bine and Little Blue rivers and their smaller 

 tributaries as to present a rugged topography. Toward the northwest 

 and southwest the surface rises in hills 1,350 feet above sealevel. The 



