12 



GEOLOGY OF LA SALLE COUNTY. 



The actual correllation of the St. Peters sand- 

 stone and the Chazy of New York is not yet proven, 

 and the exact equivalence of the Ucica cement beds and 

 the calciferous of New York may yet be questioned, and 

 we need not wonder that it is so when a well informed 

 writer tell us that so far as he knows these rocks 

 contain no fossils, when a not very exhaustive search 

 has oriven the writer one trilobite, several bivalves, 

 and two or three univalves, in all not less than a dozen 

 species of mollusks and many frag-ments of seaweed. 



The rocks of La Salle county embrace some of the 

 very old strata, rnnning- back into the Cambrian period, 

 at one time thouodit to be the theatre of the first life, 

 the morning- of the world's childhood. But we now 

 know that back of this there was life, and while the 

 Cambrian may have been one of the morning- hours as 

 marked on Eternity's dial, it was not the first, proba- 

 bh^ not the second, but ihe third or fourth in order of 

 those eras of primeval time. 



While we have representatives of ancient time, we 

 have none of recent until w^e reach the very last period. 

 Scattered here and there over the first half of the 

 geoloo-ic records, whose vast volumes are the rock- 

 ribbed hills and its leaves the fossil entombing- strata, 

 a few chapters have been taken at random and quite 

 fully presented and bountifully illustrated with minia- 

 tures and portraits of the tribes that have lived and 

 vanished, while all between is a mighty blank, and, as 

 far as any clue can be obtained from what is g-iven to us, 

 trackless void. Were the record everywhere as brief 

 as it is here we should know very liitle of the strange 

 and w onderful tribes that have lived and reig'ned for a 

 time, only to dwindle to nothingness and vanish from 

 sight forever like the meteor that for a moment blazes 

 with a brightness that eclipses the orbs of night, and 



