387 



December 1, 1853. 



The President in the Chair. 



Mr. Edward Daniels, of the State Geological Surveying 

 Corps of Wisconsin, was present, by invitation. 



Mr. Daniels, on being invited to give some account of his re- 

 cent examinations in Wisconsin, stated that he had lately spent 

 about six months in his preliminary duties, especially in the lead 

 district in the south-west corner of the state. This district extends 

 over an area of thirty-five hundred square miles. It is remark- 

 able for the absence of drift. The surface, generally, consists of 

 heavy beds of dark-red clay, containing flint and little lead ore ; 

 it is evidently the result of decomposition of the limestone rocks. 



Commencing at the west, on the Mississippi river, the lime- 

 stone is seen exposed on its banks in the high cliffs, and contains 

 lead veins. Farther east are the high table lands, and a high 

 mound, so called there, three hundred feet in height. Here is 

 the yellow, sandy, magnesian limestone ; and, above this, a shale 

 of from five to fifteen feet thick, thickening towards the west, 

 and thinning towards the east. The upper layers of this are 

 nonfossiliferous, but the lower layers are full of organic remains. 

 Some species of chambered univalves, small trilobites, the Lingula 

 lowensis, &c., all minute, when compared with similar types in 

 the rocks below. The life of this period seems to have been 

 Liliputian, and the fossils can now be gathered in immense 

 quantities. 



The mounds are capped by a formation, which does not occur 

 at any point between them, and is of a coralline nature. The 

 blue mound, the culminating point between the Mississippi and 

 Wisconsin rivers, is capped by still another deposit ; a bed of 

 hornstone, nearly three hundred feet thick, containing few fos^ 

 sils, and these difficult to secure on account of the hardness of the 

 rock. The origin of this is a question for geologists. Was it the 

 result of a sub-marine hotspring throwing up silica ? It is evi- 

 dently the result of the deposit of silica, which was once in solution. 



