330 Tertiary. 



of Wisconsin, Iowa, and Minnesota, and look at the "Natural 

 Section of Hills, Upper Mississippi;" " Cliff of Lower Magnesian 

 Limestone, Plum Creek;" "Alterations of Magnesian Limestone and 

 Sandstone, Kickapoo;" "Lagrange Mountain;" "Castellated appear- 

 ance of Lower Magnesian Limestone, Upper Iowa;" "Lower Mag- 

 nesian Limestone, Upper Iowa;" "Cliffs of Lower Magnesian Lime- 

 stone, Upper Iowa River;" "Outlier of Sandstone, Kinnikinick;" 

 "Outcrop of Upper Magnesian Limestone and Shell Beds, Turkey 

 River," and you will be enabled to form some idea of the bluffs, cliffs, 

 castellated rocks, and pinnacled outliers, that are so utterly inconsistent 

 with the glacial hypothesis. 



Such scenes are also presented in the State of Wisconsin, both within 

 what is universally conceded to be the driftless area and without it- 

 Two of these curious isolated eminences are situated in Dark Hollow, 

 north of Wingville, on the head waters of the Blue river, near the 

 junction of Badger Hollow, and composed of the Upper Sandstone, as 

 illustrated in Hall's Geological Survey. Another called the " Stand 

 Rock," in the Dells of the Wisconsin, forms the frontispiece to Vol. ii. 

 of Chamberlin's Survey. But Prof. R. D. Irving informs us that a 

 remarkable feature of all of the palaeozoic portion of central Wisconsin, 

 is the occurrence of isolated ridges and peaks, rising from 100 to 300 

 feet abruptl}', and often precipitously from the low ground around 

 them, and com^Dosed of horizontally stratified sandstone, or of sand- 

 stone capped with limestone. Such outlying bluffs lie all along the 

 face of the high limestone country of Columbia and Dane counties, 

 and are, generally, there capped by the same limestone that forms the 

 elevated land, of which they are themselves fragments, others, again 

 and these are nearly all entirely of sandstone, occur scattered widel}'^ 

 over the central plain of Adams and Juneau counties, often covering 

 but a small area, and showing bare rocks from the base to the summit, 

 which not infrequentl}^ are worn into jagged pinnacles and towers. He 

 says the driftless area occupies 12,000 square miles (but the map indi- 

 cates about 13,000 square miles) of the southwestern part of Wisconsin, 

 or neai'ly one fourth the entire area of the State and that over this area 

 the drift is not merely insignificant, but absolutely wanting. The line 

 of separation of the driftless from the drift area, is thus traced: 



Entering the State from the south, on the southern line of Greene 

 county, the drift limit travei'ses this county centrally from south to 

 north, and continues northward through western Dane and central 

 Sauk; then curving eastward across the southern end of Adams, it 



