4SO 



E. K. SOPER 



depending upon the amount of erosion which has occurred. In the 

 extreme north edge of the city, in an old quarry about 3,400 feet 

 east of the river, the top of the limestone is about 900 feet above 

 the sea. About a quarter of a mile east of this quarry, underlying 

 the Columbia Heights district, the limestone surface reaches its 

 maximum elevation for the area, about 920 feet. This shows a 

 rise of from 100 to 130 feet in a distance of about 8| miles. Most 

 of the rise, however, is in the northernmost two miles, where the 



STRUCTURE SHEET 



To accompany topoaraphic map of Minneapolis 

 £ KSOPLR 



■^ecTion Alona LaHe Street Eoit-lf^est. 



E-N Section Alona Broadway HE. and 13- Ai/er7ue'N 





E-H Section olona 44- Avenue N and City Limits N E. 



£:-iAi Section alonq 6* Avenue N. and Elm Street 

 Legend 



E3 S H3 ES3 S 

 drill an^^oil tir^^^rone' shaltf jnnj£forTc Sit IstrMi 



Scale : 1 inch '<fO0Oft 

 Fig. 2 



dip steepens appreciably. The dip in the south half of the city is 

 practically negligible. The elevation of the sandstone is corre- 

 spondingly higher in the northern portion of the area, although the 

 rise is not quite as great as in the case of the limestone, owing to 

 the fact that the limestone is several feet thicker in the Columbia 

 Heights district than in the south central portion of the city, where 

 erosion has removed the upper layers. There are several minor 

 undulations in the strata between the north and south city limits, 

 but these are so slight as to be unimportant. 



The generally flat surface of this limestone plain, back from the 

 buried river gorges, is broken here and there by small hillocks. 



