BROWN AND REDWOOD COUNTIES, 1884. WARREN UPHAM. 



presented a substantially base-leveled condition prior to the Cretaceous. The lower 

 portion of the Cretaceous consists, very generally, of kaolin clay which resulted from 

 the decay of the Archean in pre-Cretaceous ages, and which the Cretaceous ocean, in 

 whole or in part, worked over into Cretaceous sediments. This clay, which is some- 

 times ten to twenty feet thick, is likely to be of value for pottery, but is not at all 

 used at present. The undecayed Archean rocks appear abundantly along the Minne- 

 sota valley in the whole extent of Redwood county, and somewhat in Brown county. 

 The Cretaceous is also exposed along the Minnesota at New Ulm, on the Cottonwood, 

 and at Redwood Falls. The Cretaceous contains dicotyledonous leaves, in a sand- 

 stone, in the N. E. J sec. 25, North Star, a mile southwest from Springfield station; 

 also near the middle of section 35, Milford, in a similar sandstone exposed in the 

 north bank of the Cottonwood. N. H. w. 



