310 T. E. SAVAGE ALEXANDRIAN ROCKS OF ILLINOIS AND WISCONSIN 



The Mayville limestone is again well shown in an old quarry one-half 

 mile south of the town of Peebles, near the south end of Lake Winnebago. 

 Figure 2 shows the character of the strata at this place, a detailed section 

 of which is given below : 



Section of Strata exposed one-half Mile south of Peebles 



Mayville limestone. Feet 



4. Dolomite, yellowish gray, hard, coarsely crystalline, with many 



cavities and numerous nodules of chert 6 to 9 



3. Dolomite, brown to pink, hard, vesicular, in somewhat irregular 



layers 1 to 6 feet thick 30 



2. Dolomite, dark gray, in thin irregular layers, separated by bands 



of chert 3 



1. Dolomite, dark gray, with a few chert nodules 20 



The base of this quarry is only a few feet above the top of the Maquo- 

 keta shale, as is shown by the numerous springs that issue in this region 

 at a slightly lower level. In a ravine a few rods north of the quarry the 

 contact of the Mayville limestone and the Maquoketa shale is clearly 

 exposed, with no intervening bed of iron ore. 



From the residual material found in the cavities of the limestone com- 

 prising the upper member (number 4) of the quarry section near Peebles 

 the following fossils were among those collected ; 



Favosites sp. PlatystropMa daytonensts 



Halysites catenulatus Clorinda sp. 



Lyellia cf. thehesensis Rhynchonella ? janea 



Dalmanella edgeivoodensis Rhyncliotreta parva 



Orthis flabellites Atrypa putilla 



The above species of fossils indicate the Edgewood age of this lime- 

 stone and leave little doubt that at least the lower 60 or 80 feet of the 

 Mayville beds, and probably all of this limestone below the zone of Vir- 

 giana barrandei var. mayvillensis. belong to a time interval equivalent to 

 the Edgewood formation of the Alexandrian series. 



In the vicinity of Brillion, about 25 miles north of Peebles, the Vir- 

 giana zone of the Mayville limestone is well exposed 130 feet above the 

 top of the Maquoketa shale, and it outcrops again 50 miles still farther 

 north, at the township line about 6 miles west of Sturgeon Bay. 



Correlation op the Mayville Beds of Wisconsin with the 

 Alexandrian Eocks of northeast Illinois 



The fossils listed above, that were collected from the upper layers of 

 the limestone exposed in the quarry near Peebles, Wisconsin, clearly 



