502 



LOCAL SECTIONS 



species, we have not observed elsewhere ; the other appears to be one of the same 

 species found at the Falls of the St. Croix. 



Five miles below Bad Axe, and nearly opposite Winnesheik's Village, the eleva- 

 tion of the bluff is one hundred and ninety-two feet above the water-level. The 

 Lower Sandstone, F. 1, has here a thickness of three hundred and forty-two feet, on 

 which reposes a bold cliff of Lower Magnesian Limestone, one hundred and fifty-two 

 feet thick. Towards the top of this latter rock the beds are cherty, and contain 

 Euomphalus and other Gasteropoda, as well as imperfect remains of Ortlioceratites. 

 Here, as elsewhere in the region of F. 2, its cherty beds are the most fossiliferous 

 part of the formation. 



From here to Lansing, the bluffs vary in elevation from four hundred to five 

 hundred and fifty feet. The bluff at Lansing measured four hundred and ten feet ; 

 the approximate thickness of F. 1 being here two hundred and seventy-five feet, 

 and that of F. 2 one hundred and thirty-five feet, giving a decline of the strata of 

 about seventy feet in three miles. 



From this point I proceeded to examine the country situated between the Mis- 

 sissippi and the Upper Iowa, chiefly for the purpose of ascertaining the boundaries 

 of F. 3 in that direction. 



Leaving Lansing, we followed the valley of a small creek, in a westerly direction, 

 for the distance of about four miles. This valley is bounded on either side by hills 

 elevated from three hundred and fifty to four hundred feet, covered, in many cases, 

 with high grass, and a tolerably thick growth chiefly of white and black oak, 

 hickory, maple, and poplar. At the base of a number of the hills the Lower 

 Sandstone is found, and towards their summits the Lower Magnesian Limestone, 

 the latter sometimes projecting out in bold, precipitous escarpments. 



The soil in the valley is a rich, dark, sandy loam, and that of the slopes but 

 little inferior ; even on the ridges, where it has been derived mainly from the decom- 

 position of the Lower Magnesian Limestone, the soil is good, and lies well for farm- 

 ing operations. From the base of the hills issue cool and clear springs, which unite 

 to form small streams, in whose sparkling waters are to be seen an abundance of fine 

 trout. Leaving this valley on our left, we wound round the foot of a high ridge, and 

 proceeding in a northwesterly direction, we began to ascend a ravine, which led to 

 the high table-land, whence we had an extensive view of the surrounding country. 



About one mile to the west, a series of oblong mound-like elevations can be 

 seen rising above the general level of the country, similar in appearance to those 

 occurring near Bissel's Farm, in the vicinity of Lake St. Croix. On examination, 

 they proved to be composed of the same formation. At the base, is the white 

 quartzose sandstone of Fort Snelling, surmounted by buff-coloured dolomitic beds con- 

 taining Orthis, Murcliisonia, Streptoplasma, and columns of Crinoidea. These upper 

 layers occupy the same geological horizon as the buff-coloured strata at Prairie du 

 Chien, and are three hundred and forty feet above the water-level of the Mississippi, 

 and constitute the most inferior beds of the Upper Magnesian Limestone formation 

 of the Northwest. 



The height of these mounds is about eighty feet above the general summit-levels 

 of the country, of which sixty-six feet is sandstone. Westwardly they were seen 



