118 KANSAS ACADEMY OF SCIENCE. 



and south, including the median portion of these streams, and within 

 their area corrasion varies with the varying conditions of climate and 

 the grade of the country. All of the processes which are now at 

 work are dissecting the Great plains. This has not always been 

 their condition. In Tertiary times the sediments carried from the 

 Rocky Mountains were spread in a broad sheet extending eastward 

 from their base, and built up a constructional plain. This plain is 

 largely preserved to the present time, and constitutes the division 

 known as the High plains. 



The elevation of the Great plains increases very gradually to the 

 westward, and their surface is not marked by conspicuous features of 

 relief. Their more rugged portions are where the Tertiary formations 

 have been sculptured into bad lands and canons, or the areas of the 

 older rocks have been dissected by the streams. The Bad Lands type 

 of topography is found principally along their western border, the 

 High plains, or intermediate j)ortion, being simply trenched by the 

 streams crossing ft. 



The Flint Hills upland is a name suggested for a somewhat irreg- 

 ular belt of country which extends from north to south across the 

 state and terminates in a point north of the Arkansas river in Okla- 

 homa. It is in its southern part the divide or watershed between the 

 Neosho and Verdigris drainage on the east and the Arkansas drainage 

 oil the west and south. The Kansas river is the only stream which 

 crosses the upland. The Cottonwood river heads within its limits 

 near the western border, and flows eastward, extending nearly across 

 the area The eastern border of the upland is marked by a compound 

 escarpment, which is produced by the outcrop of limestones. This 

 feature is well defined at its southern portion, where it is emphasized 

 by the position of the stream valleys. The removal of the shales, 

 which succeed the highest beds of limestones, has given rise to a 

 structural plain developed on the upper surface of these resistant 

 beds. This plain has a gradual western dip, corresponding to the dip 

 of the rocks, and constitutes the general surface of the upland. It 

 blends along its western border with the Great Bend lowland and the 

 valley floors of the Smoky Hills upland. Its southern portion has 

 suffered considerable dissection, and is known as the Flint hills, 

 from which the name of the upland is derived. The northern portion 

 of the upland is dissected by Little Blue and Big Blue rivers, which 

 flow southward from Nebraska approximately along the strike of the 

 formations. They have developed well-defined valleys, and their nu- 

 merous short tributaries have sculptured out terraced hills and divides, 

 producing a quite rugged topography. 



The Flint Hills upland has no doubt had an influence in determin- 



