130 Association of American Geologists and Naturalists. 



that this limestone was the attenuated extremity of some one or more of 

 those of that state near the Trenton limestone. 



Above this fossiliferous limestone, comes the upper division of the 

 great magnesian limestone deposite, to which the name of cliff lime- 

 stone has been given by Dr. Locke. It is well supplied with fossils in 

 Wisconsin, but less so in Missouri. Its most important character results 

 from the valuable minerals it contains. It is the formation that furnishes 

 the immense amount of lead produced by the mines of Missouri, Wis- 

 consin, Illinois and Iowa. It abounds in zinc, copper, lead and other 

 metals, and recently cobalt ore to a great extent has been found in it in 

 Missouri. Dr. King presented a number of facts that appeared to him 

 perfectly conclusive that the ores of these metals were deposited con- 

 temporaneously with the containing rock. The thickness of this forma- 

 tion in the mining regions was about five hundred feet. He showed, 



t> ~~o 



however, that the comparative thinness in this direction was amply 

 made up in the horizontal extension of the formation. He found high- 

 ly flattering indications of mineral deposits far west of the region to 

 which mining has yet extended. 



Above this — the upper division of the magnesian, or cliff limestone 

 appears a deposite of pure limestone, from thirty to sixty feet thick, 

 which seems to be the lowest deposite of the proper carboniferous for- 

 mation. Above this the first coal deposits present themselves, which 

 in the western part of the state of Missouri exhibit at least two workable 

 beds. These beds of coal have the usual accompaniments of shale or 

 clay, a few feet in thickness, above and below* Next in the ascending 

 order comes a deposite of brown or reddish sandstone, containing in 

 many places extensive deposits of iron ore. This sandstone may be 

 from sixty to one hundred feet in thickness. 



Somewhere between the cliff limestone and this sandstone, there ex- 

 ist extensive sources of salt water. There is scarce a doubt that this 

 salt water could be obtained by means of Artesian wells any where on 

 the southern side of the coal basin, in Missouri or Illinois, within the 

 line formed by this sandstone. This Dr. King stated was an important 

 fact to the farming and grazing interests of these states. Above this 

 sandstone comes a deposite of limestone, whose thickness has not yet 

 been determined, containing at least one and perhaps several workable 

 beds of coal. The area of this coal basin within the limits of the States 

 and territory of Iowa, Dr. King showed to exceed that of the whole oi 

 the island of Great Britain. 



Dr. King concluded with a rapid description of the character of the 

 country whose geology he had sketched, and a few remarks on the origin 

 of prairies, showing how the noblest forests fall before the puny power 

 of a spear of grass. 



Adjourned to 4.J o'clock, P. M. 



