Cushing — Geology of Clinton County. 



571 



of the entire Chazy, followed by the Black river and Trenton, which 

 has already been noted. The structure is that of a low anticlinal with 

 northerly pitch. 



Still farther east, the Chazy beds are cut off abruptly by an apparent 

 fault at right angles to the strike. No rock shows to the eastward but there 

 is an abrupt fall in altitude of from sixty to eighty feet. This probably 

 represents the northward prolongation of the Beekmantown fault, but has not 

 yet been demonstrated as its equivalent. 



Series V. No dikes have been found in the township. 



Series VI. Besides the long esker already mentioned, nothing worthy 

 of special description has been noted. The Champlain clays are found 

 everywhere except on the extreme west. 



Champlain. 



No pre-Cambrian rocks occur in Champlain. 



Series IV. Potsdam .sandstone. The Potsdam extends into Champlain 

 from Chazy along the west side of the Tracy brook fault. It is exposed 

 quite continuously along the fault line as far as Cooperville. From that 

 point northward, dolomites appeal' interstratirled with the sandstone, marking 

 the passage beds to the Calciferous, and followed by the heavy grey dolo- 

 mites of the Calciferous itself about a mile north of Cooperville. These 

 continue to the Canada line, the whole with slight northerly dip. 



This strip of Potsdam and Calciferous along the west side of the Tracy 

 brook fault, has a width of from two to three miles, and is adjoined on the 

 west by territory in which nothing but Potsdam is found clear to the Canada 

 line, the dip being slightly to the north, as before. Not even the passage 

 beds are seen on the west. There is clearly a fault here running the full 

 length of the township in a nearly north and south direction, and throwing to 

 the east. The amount of throw is purely conjectural as the horizon in the 

 Potsdam on the west side is not known, but it has an undoubted minimum 

 value of 250 to 300 feet. The name "Champlain fault,' 1 is suggested for it. 

 Continued to the south into Chazy with the same trend, it would connect 

 with the Tracy brook fault near Chazy village, the junction of the two 

 furnishing an adequate explanation for the prominent ridge of Potsdam with 

 abnormal dips which lies west of the Tracy brook fault north of ('hazy 

 village. 



Calciferous sandrock. The Calciferous exposures in Champlain are 

 limited to the zone between the Champlain and Tracy brook faults. As these 



