REPORT ON FIELD WORK IN GEOLOGY. 1 35 



Harper there is a broad expanse of prairie almost void of undulation. 

 And although the material is soft like soil for 300 feet or more, as 

 shown in mining for salt, ami lies at an average elevation of 300 or 

 400 feet above the terrace to the east, yet the streams here scarcely 

 cut a channel, and in no instance are well defined bluffs produced. 

 But if we go still farther west to the gypsum hills west of Medicine 

 Lodge, where beds of gypsum alternate with much thicker deposits of 

 a soft soil, the terraces at once appear, the streams flow between well 

 defined bluffs, and a topography recalling that of eastern Kansas 

 greets the eye. 



So far as has yet been determined eastern Kansas does not possess 

 a composite topography. The broad valleys of her streams are 

 particularly even and straight, although within these limits the chan- 

 nels meander from bluff to bluff as though they had long ago almost 

 reached their base level. This is particularly noticeable of the 

 Kansas river. The topographic sheets issued by the U. S. Geological 

 Survey fortivnately cover nearly all the territory occupied by the 

 principal streams of the state. A careful examination of these shows 

 that the bluff lines of the Kansas river are particularly even and free 

 from the sinuous meanderings which sometime characterize valleys 

 with composite topographies. But the stream within the bluffs, as is 

 also plainly shown by the charts, meanders as gently perhaps as any 

 stream in the state. An intimate acquaintance with portions of the 

 valley makes it possible to state that the number of old river channels 

 is unusually great. Some of these are now filled with water and 

 constitute "lakes" and bayous, but the great majority of them are 

 entirely dry and are included in the cultivated fields, so that their 

 banks are becoming less and less distinctly marked. 



The stream with the most sinuous bluff lines in the eastern part of 

 the state is the Cottonwood river, a tributary to the Neosho river. 

 The upper portion of the Neosho is also much more irregular than 

 the lower. The Osage river perhaps would rank next in degree of 

 sinuosity, while the Big Blue and the Arkansas are remarkable for the 

 almost perectly even character of their bluff lines. 



Since the character of the surfaces produced by erosion has come 

 to be looked upon by geologists as of so great importance, indicating 

 as claimed by some almost the- whole history of oscillations of levels 

 since the territory in question became dry land, the topography of 

 eastern Kansas assumes a new interest. The recent discussions* re- 

 garding the origin of river channels in Missouri and adjacent states, 

 especially the Osage river channel, increases this interest. It has 

 seemed to the writer that possibly the peculiar method of widening 



* Davis and Wiuslow. Science. April -18. 1893. July ~'l. 1893. aiul November 17. 1893. 



