1847.] Geology of Lewis County. 267 



OBSERVATIONS ON THE GEOLOGY OF LEWIS 

 COUNTY. 



BY FRANKLIN B. HOUGH, A. M. 



The geological survey, authorized by the Legislature of New- 

 York, having been nearly completed, and the results published, 

 an account of the geology of particular districts may appear super- 

 fluous. But when we consider the extent of territory required to 

 be examined by each of the gentlemen employed in the survey, 

 and the absence of former observations to guide them in their re- 

 searches, it is evident that the time allotted for its completion 

 could not allow of that minute and local detail of geological phe- 

 nomena, which is often of the highest impoitance in determining 

 the age and identity of rocks, and in solvingr many of the intri- 

 cate problems which present themselves to the votaries of that 

 science. 



In this article, the writer will principally restrict himself to the 

 notice of phenomena not enumerated in the report of the Geolo- 

 gist of the Third District, and to a fuller detail of such facts as 

 may have been mentioned in the report above referred to; and to 

 which additional facts might be adduced, to amend or confirm the 

 conclusions arrived at. 



There is perhaps no department of Geology more deeply inte- 

 resting, than the study of the earlier formations, and tracing the 

 organic forms of existence, from their primeval characters, up 

 through the different geological eras to the present time. Such is 

 the character of a portion of the rocks of Lewis county, which, 

 though wanting in several of the earlier strata, yet furnish an 

 abundance of fossil remains of an exceedingly remote period, and 

 exhibit evidence of having been produced under widely different 

 conditions. 



In describing the geological characters and mineral contents of 

 the rocks of this county, I shall begin with the oldest formation, 

 and proceed in the order of time to the latest. The county is 

 nearly equally divided by the Black river; and nothing coukl be 

 more widely different than the agricultural as well as geological 

 characters of the country on its opposite sides. 



From the High Falls to the northern border of the county, a 

 distance of about forty miles, the river has a very gentle descent; 

 so slight that a dam at Carthage was alleged to have caused much 

 damage by overflowing lands thirty miles above, and give rise to 

 expensive litigations. An estimate, made in pursuance of an act 

 passed March 20, 1828, incorporating the " Black River Canal 

 Company," places the descent in the distance at fifteen feet, which 

 is probably much too high. 



