GREENE: DAKOTA-PERMIAN CONTACT. 5 



scures the underlying formations over large areas, and in the 

 second, it contains deposits of clay, sand and conglomerate 

 almost identical with those of the Dakota. However, if there 

 are any wells present, the water will be hard in the drift and 

 soft in the Dakota sandstone. 



Other Deposits of the Pleistocene. — In much of the region 

 along the west side of Mill creek in Washington county tnere 

 are fifteen feet of very sandy, jointed clays, gray above and 

 brown beneath, overlying the plain sloping towards the creek. 

 This deposit may be due to the changes which seem to have 

 been made in the direction of Mill creek in glacial times. The 

 topography and geology suggest the possibility that Mill creek 

 once flowed southeast from Washington, with a large branch 

 from the north joining it just east of Washington, while a 

 small stream used the present outlet of Mill creek into the 

 Little Blue river. There is a channel beneath Greenleaf , nearly 

 100 feet deep and filled with glacial debris, as shown by the 

 wells supplying water to Greenleaf. Along the railroad be- 

 tween Washington and Greenleaf there are no exposures of 

 rock in place, but as the region was not carefully studied this 

 evidence is not conclusive. Glacial damming of this stream 

 in the region southeast of Washington may have formed a 

 lake which sought an outlet to the north in the present valley 

 of Mill creek. 



If these suggestions are true, it was probably in this lake 

 that these deposits were formed. 



West of the Republican river at Clay Center the river bluffs 

 are terraces composed of loess-like material with calcareous 

 concretions, and native rock below. They rise to a height of 

 forty to sixty feet at the edge of the river bottom, and are higher 

 here than farther back. There is, as a rule, a fair back slope 

 of the terrace to the hills of the Dakota to the west, and the 

 junction is usually occupied by streams or branches of them 

 and the drainage is away from the river down the terrace, 

 which has a maximum width of three miles. 



It may be that this deposit is the same material as that 

 which is known as "plains marl" in the western part of the 

 state. In regard to the latter, Professor Haworth^ believes it 

 to have had the same origin as that of the Tertiary mortar 



2. Univ. Geol. Surv. of Kan., voL II, p. 275. 



