298 



GEOLOGICAL RECONNOISSANCE 



whilst on the river bottoms the timber is large, and contains, in addition 

 to the hickory, gum and elm. 



LAWRENCE COUNTY. 



The geological position of the rocks, along my route, have been mostly 

 determined by their lithological character, owing to the almost total 

 absence of organic remains; in one member alone of the magnesian lime- 

 stones were any discovered, and they were only a few very imperfect 

 casts of the genus orthis, too indistinct for determination; also a simgle 

 specimen of an orUwccraiile, which is probably new. The want of so 

 essential an aid to the determination of the position of rocks, (especially 

 where there has been a great thinning out of the members, and a condi- 

 tion which indicates a deposition on a very unequal bottom, together with 

 a subsequent cutting away by currents of the deposited members,) renders 

 the identification of equivalent formations difficult and uncertain. The 

 accompanying section may therefore require, upon more minute investiga- 

 tion and comparison, correction in some of the details; and, for the present, 

 I shall only indicate the system to which I think they will hereafter prove 

 to belong, without designating the particular member they may represent. 



The strata are lettered in the ascending order 



I l I 



i_ L _I 



L L 



CH 



CH CH 



CH 



f 



I I 



30 



15 



Rugged weathering limestone, with veins of 

 calcspar, and casts of a small cytkerea. 



White chert bed. 



1 I 



60 



Massive saccharoidal sandstone, white, red 

 dish, and variegated. 



All the members from 



(a) to (h) inclusive, be- 

 long, most probably, to 

 the lower silurian period. 

 The remaining mem- 

 bers (i) and (j ), are of 

 quaternary date. 



The thick-bedded mag- 

 nesian limestone (a) and 



(b) are the rocks in which 

 the zinc, lead, and cop- 

 per ores are usually 

 found. The copper is 

 but sparingly dissemin- 

 ated in some of the calc- 

 spar veins ramifying this 

 rock. On the property 

 of Mr. C. T. Stewart, 

 township 17, range 2 

 west, many small sam- 



