C02 GEOLOGY OF CENTRAL WISCONSIN. 



flitexta, 'S. cleflecfa, Oiihis tricenaria, Rhynconella, n. sp., Cypricardites ventricosa, 

 Raphistoma lenticularis, Pleurotomaria siibconica, Trochonema umbilicata, Murchisonia 

 bicincta, M. tricarinata, Orthoceras anellitm, 0. vertebrate. 



In the Catfish Valley, the Potsdam, Mendota, Madison and Lower Magnesian are 

 frequently exposed, the last three being quarried at numerous places. A few important 

 points only can be mentioned. O'Malley's and Veerhusen's quarries in Westport yield 

 very handsome stone, and one quite different from the general run of the Lower Mag- 

 nesian. O'Malley's quarry, S. E. qr. S. E. qr. Sec. 10, shows the following section: 



Ft. In. 



1. Thin bedded to shaly yellow limestone 6 . . 



2. Three heavier layers of the same 2 6 



3. Broken yellow limestone with much oolitic chert (641) and geodic calcite 



(642) 4 .. 



4. Very heavy layers inters tratified with two or three thin layers of cream- 



colored, close, granular-textured Limestone (640;, containing 4.06 per 

 cent, of argillaceous impurities 10 



From the heavy layers of No. 4, one of which has a thickness of 24 inches, some 2,000 

 to 3,000 cords have been removed, the stone having been chiefly used in the construction 

 of the State Hospital for the Insane. Mr. Veerhusen's quarry, N. E. qr. of the S. W. 

 qr. Sec. 25, is on the top of a narrow ridge of Lower Magnesian, and has a face of 24 

 feet, a large amount of stone having been removed. The following is the section, be- 

 ginning above: 



Ft. In. 



1. Rough, brecciated, yellow, fine-granular limestone (629), containing 3.49 



per cent, of insoluble ingredients; bedding indistinct 8 



2. Very heavy layers, some 4-5 feet in thickness, of pale yellow, close-textured, 



granular limestone (626, 627, 628), which on solution leaves a large res- 

 idue of fine gray sand, several determinations on specimens from dif- 

 ferent parts of the face giving 12.14, 13.03, 20.59, 34.74, 35.63, and 40.78 

 per cents. ; quarry layers 15 



3. Greenish sandy layer (629)^); a specimen on solution left 41.17 per cent. 



of very fine gray sand 1 



4. Thinner-bedded limestone, like No. 2, but finer-grained, of greenish tint, 



and profusely marked with dendritic oxide of manganese; below the 



base of the main quarry; thickness 8 6 



The lowest layer is 39 feet above the base of the formation. No. 2 lias yielded a 

 very large amount of stone for the construction of the Insane Asylum. The stone is 

 like that from O'Malley's quarry on Sec. 10, and should have much wider use than form- 

 erly. It is a much handsomer stone, and endures weathering better than the sandstone 

 used in Madison. The upper and less sandy layers at Veerhusen's have been burned 

 into a good lime. At Westport Station, near the center of Sec. 26, is a long railroad 

 cutting through the western end of the ridge upon which the quarry just described is 



situated. The deepest part of the cut shows the following section : 



Ft. In. 



1. Lower Magnesian limestone (636); gray-and-yellow-mottled, porous, mode- 



rately thin-bedded, the layers somewhat broken and displaced; con- 

 tains 11.52 percent, of argillaceous impurities; at base is a thin layer of 

 white oolitic chert, and another of greensand; in all 20 



2. Madison sandstone, including: thick-bedded, yellowish, fine-grained sand- 



stone (637), with only 2 per cent, of soluble ingredients, 19 feet; lighter 

 colored sandstone, 2 feet 6 inches; and purely silicious, white sandstone, 

 4 often loose, and composed of much rolled quartz grains, 4 feet; in all. . 25 6 



