NIAGARA LIMESTONE. 357 



WAUKESIIA BEDS. 



The terra Waukesha limestone was selected many years since by 

 Dr. Lapham, to designate the thin bedded strata that occur at Wau- 

 kesha, and their equivalents elsewhere. 1 This term was also adopted 

 by Prof. Hall, in the report of 1862. 2 It seems therefore desirable 

 to retain a name that has already become fixed in the literature of the 

 subject, although we shall be compelled to restrict its application, and 

 to entertain, to some extent, different views as to its relations. 



There are at Waukesha three classes of limestone. In the quarry 

 near the college, the upper fourteen feet consist of a soft, yellowish, 

 coarse-textured dolomite, that has been identified with unquestioned 

 correctness, as the equivalent of the Racine limestone. This reposes 

 upon regular, even beds of a hard, compact, fine-textured, crystalline 

 dolomite, of gray color and conchoidal fracture. It is characterized 

 by the presence of much chert in the form of nodules, distributed 

 chiefly in layers, coinciding with the bedding joints. These strata 

 abound in Orthoceratites, but contain few other fossils. They consti- 

 tute the type of the Waukesha beds. The transition to the Racine 

 beds is quite abrupt, but does not correspond to a bedding joint. 

 From three to four inches of the base of a thick layer are of compact 

 rock, like that below, while the remainder has the open texture and 

 fossils of the Racine beds. 



Passing by several intermediate quarries, for the moment, we find 

 at the lime kilns, two miles above Waukesha, a fine display of the 

 Racine limestone reposing upon similar cherty flags, which form the 

 sole of the quarry. The transition is accomplished in a manner pre- 

 cisely similar to that above described. 



In the road, south of this quarry, the porous Racine rock appears, 

 but one hundred yards beyond, and at the same elevation, occurs a 

 light colored, hard, compact, close-grained, subcrystalline dolomite, 

 resembling closely the Waukesha flags, except that chert is absent. 

 A few rods further, a quarry has been opened, exposing these strata 

 more satisfactorily. In addition to the close textured rock, there are 

 layers of mottled blue and white color, and irregular, lumpy struc- 

 ture, such as are associated with the even-bedded rock in the vicinity 

 of the Niagara reefs near Milwaukee. Several openings follow at 

 short intervals, including the main quarry of Mr. Hadfield, all of 

 which exhibit the same character. This is also true of the several 

 quarries on the opposite side of the Fox river. I have elsewhere dem- 



1 See Owens 1 Geological Survey of Wisconsin, Iowa and Minnesota, p. 455. 



2 Geology of Wisconsin, 1862, pp. 56-64; also note on pp. 446-448. 



