Geological Survey of the State of New York. 83 



" Could we establish the connexion, now supposed, between the 

 rocks of St. Lawrence and Jefferson, and those of the counties 

 south, it would be an important link in the chain of facts connect- 

 ing the origin of those rocks, the relative period of deposits, the 

 slope of the country, the direction of the valleys, in fine, it would 

 be the gathering up of a mass of the history of ancient times, 

 of the most interesting character and bearing generally on the 

 geology of the state." 



Mr. Vanuxem's report is chiefly of Lewis county, with a more 

 particular notice of the rocks found in his district, than he has 

 before given. 



The geologists of the third and fourth districts, have made fre- 

 quent reference to the agency of igneous causes, to account for 

 many of the phenomena observed in their field of observation. 

 Among these, none are more curious than the following, describ- 

 ed by Mr. Vanuxem, 



Speaking of the rock at Middleville, near Little Falls, which 

 there " rests immediately upon the primary," he says : — " The 

 'calciferous sandrock' in many localities abounds with cavities 

 large and small, often containing rock crystals, and small quanti- 

 ties of anthracite coal. Frequently the large cavities, which are 

 in part filled with crystals, have a covering of coal, which is flat- 

 tened or depressed towards the center, showing that the coal was 

 in a soft or yielding state. In other cavities, the coal is sometimes 

 found in the form of drops or buttons. These facts show that 

 the coal was once bituminous, and has by heat been changed to 

 anthracite. Li some of the cavities, the whole of the crystals, 

 amounting to a peck or more, have their angles and edges round- 

 ed from friction, either from water having entered with a circular 

 motion, or that a motion of the kind had originated from either 

 vapor or gas. That this rounding of the angles and edges of the 

 crystals was anterior to the solidification of the coaly matter, is 

 evident from the fact of the anthracite covering in the manner 

 above mentioned, the crystals which had been rounded by rub- 

 bing one against another." 



The configuration of the surface of Lewis county, is worthy 

 of remark. The Black river, which enters it on the southeast, 

 runs northwest, drains the whole county, divides it into two 

 nearly equal portions, and is the line of separation between the 

 primary rocks on the east, with its barren soil and extensive dilu- 



