190 W. UPHAM MODIFIED DRIFT IN SAINT PAUL. 



50 to 60 feet, this being the height of its steep ascent near the northwest 

 end of lake Como, and of the slopes which descend from the plain to 

 large bowl-shaped hollows that contain lakelets within a half mile north 

 of the Como lake and park. In these hollows masses of ice remained 

 after the contiguous parts of the ice-border had retreated, while the depo- 

 sition of the stratified drift rapidly built up the enclosing plain. 



k. PL A TEA U OF WESTERN AND PHALEN A VENUES. 



One to one and a half miles east of lake Como, after crossing an inter- 

 mediate till area, Phalen avenue extends over a plateau of stratified 

 gravel and sand, which reaches a mile from northeast to southwest, with 

 a maximum width of nearly a half mile. Its height is 925 to 935 or 940 

 feet above the sea, the nearly flat expanse having a very gentle descent 

 southwestward, amounting to about 10 feet in its length of a mile. The 

 line of northern extension of Western avenue passes over its northeast 

 part. On the northwest, this plateau is bordered by a depression 25 to 

 60 feet lower, declining northeasterly ; and on the southeast it has a 

 steep descent of 50 to 75 feet, to a morainic till area (in part thinly over- 

 spread Avith kame gravel and sand), which, varying in height from 850 

 to 950 feet, stretches four miles east to lake Phalen and White Bear 

 avenue, with a higher but smooth area of till continuing farther east. 



5. PL ATE A U OF WESTERN A VENUE AND LA WSON STREET. 



A small plateau of modified drift, about a half mile long, trending 

 from east-northeast to west-southwest, and a third of a mile wide, is 

 crossed by the most western half mile of Lawson street and by Western 

 avenue. The Gorman school is situated on its southern verge. ' Its alti- 

 tude is 900 to 905 feet, with the adjoining land on all sides 40 to 50 feet 

 lower. The modified drift of this plateau is thus about 50 feet thick. 



6. PLATE A U NORTH OF EAST UNIVERSITY AVENUE. 



Considerable portions of this sand and gravel plateau have been re- 

 moved in building Rice and Jackson streets and Pennsylvania and 

 University avenues. The plateau reached continuously about a mile 

 from west to east, before the large gaps were cut for these streets. West- 

 ward, it terminated in a narrow, esker-like, but level-topped ridge, trend- 

 ing to the northwest, while the main plateau trends east-northeastward. 

 Its height is 905 to 915 feet, with a wide depression 50 feet lower on the 

 north and a steep descent of 60 to 75 feet on the south. Its depth of 

 stratified sand and gravel is 50 to 75 feet, lying on till. 



Eastward, three outlying small plateaus of the same modified drift, 

 each about a sixth of a mile long, decline in height, successively, to about 



