GEOLOGY OF EASTERN WISCONSIN. 



southeast (center E. |- Sec. 30, Fredonia) is Smith's quarry, where we 

 rind a very soft, porous, granular, friable, cream colored dolomite, 

 belonging, undoubtedly, to the Niagara formation. At Newburg, 

 three miles and a half to the northwest, occurs one of the more com- 

 mon varieties of the Niagara limestone. To the south, similar Niag- 

 ara rocks frequently outcrop. To the northward, there is heavy drift 

 for twenty miles. The deposit under consideration lies at a lower 

 elevation than the rock at Newburg, and at about the same as that at 

 Smith's quarry. It is nine miles distant from the lake, and twenty- 

 six miles distant from the deposit on Mud creek. It is evident from 

 these facts that the stratigraphical relations of the deposit contribute 

 nothing but negative indications, and the question of its age and 

 equivalency must rest upon its lithological character and organic con- 

 tents. While it is evident that neither of these is entirely decisive, 

 yet it is apparent that the weight of their testimony is in favor of re- 

 ferring this formation to the base of the Lower Helderberg group. 

 The same may be said of the formation near Milwaukee. The limited 

 area of these deposits, and their intimate association with the Niagara 

 limestone, taken in connection with the unusual changeableness of 

 the latter formation, both as respects its lithological character, and 

 organic contents, merits consideration however in this connection. 

 On the accompanying maps, the two areas will be found represented 

 by checks of the color of the Niagara formation, at once indicating 

 their relationship to that formation, and their distinction from it. 



Economic Considerations. The rock near Waubakee has been 

 burned for lime with fair success. It is not, however, to be recom- 

 mended for that purpose, since, in the vicinity, dolomites of the 

 Niagara formation of superior quality abound. Certain layers fur- 

 nish excellent building material, and the thinner beds serve a tem- 

 porary purpose as flagging, but their tendency to split is detrimental 

 to their durability. The same remarks are true of the formation near 

 Milwaukee. Both are very serviceable for the purposes of Macad- 

 amizing, owing to their hardness, and, at the same time, the ease with 

 which they are reduced to the proper form. 



