HAMLINE AND COMO PLATEAUS. 189 



covered with modified drift, excepting near the middle of that side, 

 where an esker or rather broadly rounded and in part flat-topped ridge 

 of similar height as the plateau plain extends from it northeasterly to 

 the House of the Good Shepherd and onward to the Calvary cemetery. 

 On the west the Hamline plateau is likewise bordered by lower land of 

 glacial drift or till, whose hollows descend 25 to 50 feet, with tracts of 

 morainic hillocks that rise nearly to the same height as the modified 

 drift plateau. Only on the southwest' is this plateau, with the connect- 

 ing sand tract that continues southward to the Summit Avenue plateau, 

 bordered by slightly higher land, which is morainic till. 



The depth of the Hamline gravel and sand, as shown by wells, is 

 mostly from 30 to 50 feet. At Hamline University, which is near the 

 center of this area, and thence northwestward, the surface is mostly sand, 

 but other parts are interbedded sand and gravel. Here, as in all these 

 plateaus, the gravel contains, in its coarser layers, pebbles and rounded 

 cobbles up to six inches or sometimes a foot in diameter. 



3. COMO PL A TEA U. 



Undulating or broadly ridged sand and gravel, occupying a width of 

 a mile, with crests at the same elevation as the plains on the south and 

 north and with depressions 10 to 30 feet lower, join the Hamline and 

 Como plateaus. West and northwest of lake Como, within an eighth to 

 a quarter of a mile from the lake, moderately and in part steeply ascend- 

 ing slopes of gravel and sand rise to a flat plain 45 to 60 feet above the 

 lake, or 930 to 945 feet above the sea. This plateau or plain stretches 

 nearly three miles from east to west, with a slight ascent northwestward, 

 attaining an altitude of 960 feet on the northern part of the State Agri- 

 cultural College farm. On the north it is bordered by slightly higher 

 areas of till, more or less covered with undulating modified drift. South- 

 westward, in Saint Anthony Park and on the State farm, it is in part 

 bounded by a narrow northwest to southeast moraine belt of till, which 

 rises some 50 feet above the highest northwest part of the plain, and in 

 part southward by depressions in the moraine which sink 40 to 50 feet 

 below the southern and lowest part of this Como plateau. 



The descending southward slope of the plain is due undoubtedly to 

 the abundance of the supply of drift overloading the streams that flowed 

 from the melting ice sheet, so that this deposit formed a wide flood-plain 

 inclined 10 or 15 feet per mile. The adjoining ice-sheet on the east, 

 north, and west confined the flooded streams and their modified drift, 

 causing the northern part of the plain to lie probably 15 to 25 feet above 

 the level of the glacial lake on the south. 



The maximum depth of the Como gravel and sand deposit is at least 



