38 CHICAGO ACADEMY OF SCIENCES. 



The collecting area is thought to be in the portion of the 

 moraine west and north of Palatine. The moraine west of Pala- 

 tine attains an altitude of loo to 120 feet above the station, and 

 the crest in Lake County has nearly as great an altitude. The 

 superficial drainage is very poor north of Palatine, on the divide 

 between Salt Creek and Buffalo Creek, and it is also poor west 

 of Palatine, for there is no stream nearer than Fox River to re- 

 ceive its waters. Consequently much of the water must evapor- 

 ate or find outlet by underground passages. There seems to be 

 a sufficient collecting area and also a sufficient variation in altitude 

 to account for the wells and the difference in head. 



Salt Creek Flowing Well District. — South of Palatine Town- 

 ship, along Salt Creek and its tributaries, flowing wells are fre- 

 quently obtained. They differ but little from springs w'hich occur 

 along the creek. There are at least six such wells along a trib- 

 utary of Salt Creek in the eastern part of Schaumberg Town- 

 ship (T. 41, R. 10 E.), none of which exceed forty-five feet in 

 depth. Those along Salt Creek, from Plum Grove, in southern 

 Palatine Township, to the vicinity of Elmhurst, in York Town- 

 ship, seldom exceed thirty feet in depth. 



In Itasca there are a few flowing wells along a tributarv of 

 Salt Creek. Of these the deepest one recorded is but twenty- 

 eight feet. The water here will rise not more than three feet above 

 the bed of the creek. This level is sixty-five to seventy feet lower 

 than the level of the flowing wells in Palatine. 



OUTEK BOEDER PHENOMENA. 



While the ice sheet was forming the Valparaiso moraine 

 there were streams of water issuing from its outer border and 

 escaping down the Des Plaines River. These streams became over- 

 burdened with material derived from the ice and in consequence 

 built up their beds and valley bottoms to a marked degree. The ' 

 filling reached such a stage that the streams were in some cases 

 forced to find outlet across the present interfluvial tract. Valleys 

 were formed by these streams w'hich are now abandoned or occu- 

 pied by insignificant brooks (i). 



From the contour maps prepared by the United States Geo- 

 logical Survey it is possible to ascertain the height to which the 

 filling extended along the lower part of the Du Page and the 

 Des Plaines and the elevation of these abandoned channels. From 



[1] Perhaps the valleys here referred to were partially opened by subglaeial 

 streams at tlie time when the moraine" which they cross was occupied by the 

 ice sheet. 



