EROSION AL HISTORY OF DRIFTLESS AREA 75 



Near Montford, 

 north part 

 Mineral Point 

 Quadrangle 



1610 



200-Niagara 



100-Maquoketa 



110-Galena 



410 



1200 



Near Platte Mds. 



west central 



part ^lineral 1440 



Point Quadrangle 



Four miles south 



of Shullsburg, 



south part 1375 



Mineral Point 



Quadrangle 



200-Niagara 

 oO-Maquoketa 



250 



1190 



17C-Niagara 



170 



1205 



1260 



Near Erie School, 

 north part Eliza- 

 beth Quadrangle 

 Terrapin Ridge, 

 south part Eliza- 1135 

 beth Quadrangle 



130-Niagara 



130 



1130 



05-Niagara 



95 



1040 



Near Church, 

 north part 

 Waukon 

 Quadrangle 

 Near Monona, 

 south part 

 Waukon 

 Quadrangle 

 Near Updegraff, 

 central part 

 Elkader 

 Quadrangle 



Third Series — Waukon 

 Elkader Quadrangle in loiva 

 200-Niagara 

 100-:\Iaquoketa 

 1766 216-Galena 



616 



1250 



1555 



200-Niagara 

 100-Maquoketa 

 45-Galena 



345 



1210 



1200 



10-Niagara 



10 



1190 



Gibraltar Rock, 

 central part 

 Baraboo 



Quadrangle 



Six miles south 

 of Hillsdale, 

 southern part 

 Richland Center 

 Quadrangle 

 Near Preston, 

 northeast part 

 Lancaster 



Quadrangle 



Three miles east 

 of Bankston, 

 Iowa, southeast 

 part Lancaster 

 Quadrangle 



FoiirtJi Series — Baraboc, 

 Richland Center. Lancaster Quadrangle 

 200-Niagara 

 100-JIaquoketa 

 1870 240-Galena 620 



80-Platteville 



1250 



1815 



1610 



200-Niagara 

 100-Maquoketa 

 240-Galena 

 5-Platteville 



200-Niagara 



100-Maquoketa 



140-Galena 



545 



440 



1270 



1170 



1290 140-Niagara 



140 



1150 



