NIAGARA LIMESTONE. 355 



6. Rather hard, compact dolomite, mottled with purplish, pink and 



white, containing a few very small drusy geodes. Weathers smooth, 1 ft. 6 in, 



7. Coarsely porous dolomite, of uneven texture, prominently mottled 



with scarlet, pink and purple, and containing corals and drusy 



geodes. Marked with stylolites 2 ft. 3 in. 



8. Rather hard, firm, laminated dolomite, rather thin bedded, having a 



bnttle, uneven fracture. In successive beds of 9^, 13, 9, 13, and 



5% inches 4 ft. 2i in. 



9. Very fine grained, compact, flint-like dolomite, of smooth, hard, semi- 



conchoidal fracture, and bluish and yellowish gray color. In beds 



of 11, 1%, 4:%, 5, 3%, 4%, 9, 6>4, and 7 inches respectively 4 ft. lOf in. 



10. Compact, but more granular crystalline than the above, of whitish 

 gray color. In beds of 9> 6, 9, 8>, 2%, and 11 inches, the lowest 

 of which is banded with purple 3 ft. 10 in. 



Total 28ft. 



In the vicinity, higher and more fossiliferous beds find limited exposure. In Sec. 25 

 of this town, there is -a peculiar outlier of 18% feet vertical exposure, presenting no 

 v>rell- defined bedding. The rock is a rather hard, coarsely brecciated, light colored 

 dolomite, weathering very rough, and containing few fossils. It resembles some of the 

 brecciated portions of the Lower Maguesian limestone previously described, but more 

 especially the reef structure of the Racine limestone, yet to be considered. 



Passing by a number of minor outcrops in this vicinity, in Sec. 5, of the town of Cato^ 

 is a notable ledge arising to the height of 46 feet, which consists of heavy, irregularly 

 bedded dolomite, of coarsely brecciated structure for the most part, but, to some extent, 

 coarsely granular, and containing abundant cavities of various sizes, often filled with 

 calcite, many of which are evidently the result of the entire or partial removal of fossils. 

 Corals are present in abundance. In the N. W. ^ of the N. W. % of the same section 

 is an isolated ledge of somewhat similar character, but rather more thin-bedded and 

 compact, and differing from the former in the presence, in some layers, of much chert, 

 in which fossils, most beautifully silicified, are abundant, Pentamerus oblongus beinj^ 

 the predominating form. In Sec. 6 of the same town, on the farm of Mr. J. Mendlik, 

 is a conspicuous ledge, consisting of very heavy bedded, rough, inegular dolomite, of 

 varying hardness, usually rather soft, brecciated for the greater part, white or gray 

 in color, and variously mottled and streaked with pink. The structure is very irregular. 

 The rock contains many corals, especially those belonging to the genus Favosites, and 

 a few other fossils. 



Another noteworthy ledge occurs near the middle of the south half of Sec. 36, town of 

 Richland. The following section, in descending order, was noted at that point: 



1. Hard, white, compact, somewhat cherty dolomite, containing occa- 



sional cavities, and showing a slight tendency to separate on the 

 weathered surface into thin beds 10 ft. 



2. Hard, grayish white dolomite of uneven texture, and subcrystalline, 



irregular fracture, marked by numerous argillaceous, lamellar part- 

 ings, and a few geodes. Weathers irregularly into deep pits. In 

 layers of 3 feet 4 inches, 2 feet 6 inches, and 3 feet 8 ft. 10 in. 



3. A softer and more granular stratum, containing Cyathophylloid corals, 



which were not observed in the upper beds 3 ft. 2 in. 



4. A stratam of irregular, grayish white, shaly dolomite of uneven tex- 



ture, which weathers into rough creases 4 ft. 



