316 GEOLOGY OF EASTERN WKOON8IN. 



cept some new or doubtful species, may be found in the table of fossils 

 of the Trenton period. 



Industrial value. This formation makes two notable contributions 

 to the soil derived from it, either directly, or through the medium of 

 the drift. The one arises from the clayey members of the formation, 

 and furnishes an argillaceous constituent to the soil. They usually 

 contain, also, some lime, which, with the interstratified limestone, adds 

 a calcareous ingredient. The other has its origin in the arenaceous 

 shales, which give rise to a somewhat sandy soil. The two mingle 

 for the most part, producing an intermediate and excellent soil. In 

 portions of the towns of Ottawa, Eagle, Palmyra, and La Grange, 

 however, the sandy element is objectionably prevalent. 



The decomposing shales are used in the manufacture of brick, of 

 which they make an excellent quality. Some of the clays of this 

 formation possess an exceptionally fine texture, and are much freer 

 from sand, or grit, than most drift clays, and hence are to be recom- 

 mended for those purposes that require such a clay. These chiefly 

 lie in the upper part of the formation. 



It may be remarked, in view of the unwarranted expenditures that 

 are likely to be made under false advice, or superficial knowledge, that, 

 however much any portion of this formation may resemble, in general 

 aspect, any portion of the Coal Series, there never has been, and there 

 is no likelihood that there ever will be, any workable deposit of coal 

 found either in, or beneath it. No reliance whatever is to be placed on 

 the physical nature of the rock. The fossils found in it, which, in this 

 and other formations, are given with unusual fullness, demonstrate 

 the utter folly of enterprises looking to the discovery of coal in or be- 

 neath this formation. 



Distribution and Local Details. The most southerly point at which the Cincinnati 

 beds have been observed in outcrop is near the middle of the south line of Sec. 9, in 

 the town of Eagle, Waukesha county. The exposure at this point is very slight, and 

 consists of impure limestone, a portion of it having an earthy and a portion, a granular 

 crystalline texture, full of small cavities, and speckled with ocherous spots. A sufficient 

 number of imperfect fossils are present to determine the position of the rock, which is 

 near the upper face of the formation, but not immediately beneath the Niagara lime- 

 stone, there being a bed of clay or clay-like shale between. In tliis vicinity the drift 

 contains many blocks of a fine-grained, dark clay shale, and a lighter colored, olivaceous 

 gray, arenaceous rock, having a somewhat shaly structure. The two kinds are not un- 

 commonly united in one bowlder, but the former soon disintegrates on exposure. The 

 slaty portion also contains many comminuted fragments of Lingula, provisionally iden- 

 tified as Lingula Maquoketa, and of indistinct graptolitic remains, similar to Cliina- 

 cograptus. As this is a very soft rock, and the blocks are little worn, and are essen- 

 tially confined to this vicinity, where the glacial moraine crosses the Cincinnati belt, it 

 is safe to conclude that it forms one of the members of the Cincinnati group at this 

 point. This is confirmed by the fact that precisely similar rock occurs between 150 and 



