EROSION AL HISTORY OF DRIFTLESS AREA 95 



COMPUTATIONS SHOWING THE RELATION BETWEEN THE SLOPE OF A PLAIN 

 MADE BY THE COMBINATION OF THE DODGEVILLE AND LANCASTER ^ 

 PLAINS AND THE DIP OF THE STRATA 



^J£ 



General Location 



Location of Points 



o J^ 



o 2 

 So 



^^ Pi 



3 O^ 



O is 



S ft 



Lancaster 

 Quadrangle 



Denzer- 

 Sparta-Rich- 

 land Center 

 Quadrangles 



A-Fennimore (Dcdgc- 

 ville plain) 



B-Blake Prairie 

 (Lancaster plain) 



C-Rockville (Lan- 

 caster plain) 



A-Denzer (Dodge- 

 ville plain ) 



B-Sparta (Dodge- 

 ville plain) 



C-Loreta (Lan- 

 caster plain) 



S 16°W 15. S 27°W 22.8 



S41°W 40. S28°W 14. 



Waukon A-Church (Dodge- 



Quadrangle ville plain) 



in Iowa B-3I2 mi.S. E. of Lan- S 76°E 



sing (Lancaster plain) 

 C-3 mi. S. E. of Wat- 

 son (Lancaster plain) 



20.6 S 27°W 20. 



Lowa- A-Near Graham, Iowa 



Wisconsin- (Dodgeville plain) 



Illinois B-Lancaster, Wisconsin 



( Lancaster plain ) N 78 ° E 

 C-Stockton, Illinois 



(Lancaster plain) 



5.2 S 6°W 8. 



flat before its uplift and disGGction. Many remnants of the 

 higher surfaces stood above it, and even its general lowland 

 topography lacked much of being perfectly flat, as is true 

 of all peneplains. 



The Lancaster plain even considered alone, bears strong 

 evidence in favor of the plural cycle theory. And there is 

 corroborative evidence of other sorts which adds still fur- 

 ther to the strength of the case thus far developed. 



Antecedent Streams 

 The antecedency of streams and the nature and value of 

 the evidence it bears on the erosional history of a region 

 were discussed in Part I, pp. 21-24. Streams may become 

 antecedent (1) by local warping of the strata and surface 

 of a region after the course of the streams have been estab- 



