378 GEOLOGY OF EASTERN WISCONSIN. 



stone. In the former case the formation is so similar to the reef structure of the Racino 

 limestone that it is quite possible it should be so grouped, as has been done in description. 

 In the latter case, however, there is a nearer approach to a lithological distinction than 

 elsewhere, the Guelph beds being more regular and compact than the subjacent Racine. 

 Gasteropods predominate among the fossils. 



At Noessen's quarry, north of Saukville, (Sec. 26, N. E. j^), there is a limited open- 

 ing upon an ancient reef, exposing a rock of varying character, a portion of it being very 

 soft and coarsely granular, while other portions are compact and fine grained. Some 

 portions are made up almost wholly of Crinoid stems and Corals, while others are brec- 

 ciated. In color the rock is buff, weathering to a deeper and more reddish hue. Corals 

 and Crinoids are abundant, and only extensive quarrying is needed to make this locality 

 valuable to the collector. The fauna shows a mingling of Guelph and Racine species. 

 The locality is rather to be regarded as Racine than Guelph. 



At the light-house point, near Sheboygan, we find a hard, mottled, bluish dolomite 

 of subcrystalline, rather compact, but not uniform texture. A concentric structure, de- 

 veloped in blue and white, is frequent. This and the mottling, brought out by the pol- 

 ishing of the glacier, and swept by the waves, give the surface a unique beauty. The 

 general dip is to the southward, but after passing a low axis north of the point the slope 

 is in the opposite direction. Near Sheboygan Falls, the rock is similar, though at a 

 few points, a tendency toward the granular character, so common to the south, is mani- 

 fested. 



At Roth's quarry, N. W. ^ of S. E. ^ of Sec. 9, Sheboygan, the greater portion of 

 the rock in the main quarry east of the kiln, is a thick bedded, bluish dolomite, quite 

 hard and comparatively free from cavities, but with occasional geodes of calcite and 

 more rarely iron pyrites. Some portions are beautifully laminated. Other portions are 

 more granular and lighter in color, and approach somewhat the granular rock found 

 farther south. In general aspect and lithological character, it somewhat resembles the 

 rock of Vaughn's quarry, near Racine, already described. This and all the rocks of this 

 vicinity, have but a meagre content of fossils. A few rods west of this, there occurs a 

 hard, shaly, bluish, magnesian limestone with argillaceous partings and laminae. Tho 

 layers are undulating and the dip various. 



At Rabie's quarry (middle N. % Sec. 7, Sheboygan), occurs a rock that differs from 

 any found elsewhere in the degree of development reached by certain tendencies of this 

 much varying formation. The vertical exposure is but slight. The upper layers are 

 rather even and compact in texture, but below, the rock is highly brecciated with much 

 argillaceous matter associated as a sort of matrix. The dolomite is a deep blue, while 

 the argillaceous matter has a greenish cast, thus giving the rock a much deeper color 

 than that of other portions of the formation. These layers are very geodiferous, the 

 frequent cavities being drusy with calcite. The brilliancy of these, in strong contrast 

 with the deep color of the rock, led an interested party to believe that there was silver 

 present, and a little iron pyrites scattered sparsely through the rock, raised even brighter 

 hopes, which we were seemingly cruel, but really kind, enough to dissipate. 



At Howard's quarry, on the Sheboygan river, the rock is very irregular, both in bed- 

 ding and structure. It varies from a soft granular, to a hard, almost flint-like dolomite. 

 It contains many cavities, and weathers to an exceedingly rough, pitted surface. The 

 more granular rock is white, and the more flint-like, bluish. The bedding is too obscure 

 and irregular to give any reliable dip. The rapids here, as in most other cases within 

 this formation, are due to the changeable nature of the rock, and not to the fact that a 

 uniformly soft layer underlies a harder one, as is commonly true of falls. 



In the town of Carlton, Kewaunee county, we find the most northern exposure of 

 this formation yet recognized. It consists of a soft, granular, disintegrating, cream or 

 buff colored dolomite of irregular bedding and structure. The fauna is peculiar, in the 

 presence of large Gasteropods and Lamellibranchs. 



