62 IOWA ACADEMY OF SCIENCES. 



However, I am not yet fully convinced. Of the somewhat 

 numerous discoveries of glacial scorings in this region, nearly 

 all are on the very brow of the west bluff bordering the Mis- 

 sissippi flood plain, where they wcuJd offer the best possible 

 opportunity for erosion. It would therefore seem that they 

 ought to be the records of the very latest invasion. And all 

 these, without a single exception, show southwestward move- 

 ment. 



SOME FACTS BROUGHT TO LIGHT BY DEEP WELLS 

 IN DE3 MOINES COUNTY, IOWA. 



BY FRANCIS M. FULTZ. 



During the past year a number of deep wells were sunk in 

 Des Moines county. Some of them reached such extraordinary 

 depths before touching rock, or without touching rock at all, 

 as would clearly show the presence of buried river channels. 



In a paper presented before this society a year ago I stated 

 that the preglacial and present drainage systems in this region 

 were practically the same. From facts recently brought to 

 light I must necessarily change that opinion. To what extent 

 remains yet to be seen. 



My attention was first called to the presence of buried water 

 courses in this locality by Mr. Frank Leverett, of the United 

 States Geological Survey, who has collected a large mass of 

 data on the glacial phenomena of this region. He has already 

 given us a general discussion of the preglacial conditions of the 

 Mississipjoi basin^; and in the course of time we may hope for 

 further and more detailed contributions along the same line. 



The deep wells in question are located some eight or nine 

 miles north of Burlington. One is on the farm of L. Aspel- 

 meier, near Latty station. It is 233 feet deep, and penetrates 

 the rock but two feet. Unfortunately there was no record kept 

 of the character of the deposits passed through, which is also 

 true of the other wells to be mentioned further on. Therefore 

 the details are somewhat meager. As nearly as could be deter- 

 mined the till continued to a depth of 188 feet, where a gravel 



1 Journal of Geology, p. 740, Vol. Ill, No. 7, 1895. 



