Malott: The "American Bottoms'' Recjiov 43 



their origin in sand have broad seeps at the foot of their 

 steep slopes because of the permeabihty of the sand plain 

 above. 



Development of Post-Glacial Clifty Creek. Cliffy Creek 

 valley has been deeply excavated since Pleistocene time and 

 has developed some unusual characteristics inherited from the 

 , period of adjustment subsequent to the ablational period of 

 the ice. Its line of discharge after passing out at the middle 

 of section 36 was up the pre-glacial valley of Little Clifty 

 Creek for a short distance, high above its present level. It 

 then curved westward and then to the north where it de- 

 scribed an unusual ox-bow, returning to within 125 yards 

 of itself, but continuing on southward and touching the north 

 edge of section 2 before bending back into another ox-bow 

 with a southwardly directed loop. In the first large loop 

 about the center of section 35, it passed over the position of 

 its filled pre-glacial valley, but on turning back from this 

 loop it never again encountered the old valley. After having 

 made an unusually striking double loop in the southwest quar- 

 ter of section 35, it at first took a course in a generally south- 

 west direction thru a sag in the ridge that formerly separated 

 its valley from that of Plummers Creek. This consequent 

 stream must have flowed at an elevation of approximately 

 650 feet above sea level, or 90 feet above its present level in 

 the southwest part of section 35. After entrenching itself 

 some 10 feet below this level it remained stationary for a 

 long time, allowing the pre-glacial portion of the stream, the 

 part above the mouth of Little Clifty Creek, to become silted 

 up with the incoming material from the surrounding area. 

 Since then the stream has slowly cut downward, and the silt 

 of the middle and upper parts of the valley has been largely 

 removed. The great meanders in section 35 were entrenched 

 in situ. The northwardly intended meander in section 35 has 

 become greatly enlarged on account of having been formed 

 in the pre-glacial filled valley. The outside of this meander 

 has always been a bank composed of unconsolidated sand. 

 The stream today still swings against this sand bank on the 

 western and southern sides, and the numerous sand slides 

 carrying in the vegetation testify to the continued growth 

 of the meander. The next meander looping broadly toward 

 the south was also probably smaller originally, and has been 



