74 SPARRY LIMESTONE. 



lions of the same mass. Other causes also seem to have oi)erated at times, in such a manner 

 as to break up tlie already consolidated strata, which were subsequently reconsolidated 

 without removal ; at least we find angular fragments united by the intervention of calca- 

 reous spar. 



No fossils have j^et been discovered in this rock, though it must be confessed that suffi- 

 cient examination has not been made for microscopic bivalves. In searching for fossils, it 

 will be necessary to caution against the mistake which might be made in some localities, 

 by confounding the Calciferous sandstone with the Sparry limestone. 



MINERAL CONTENTS. 



Sulphurets of lead and zinc. The Sparry limestone is the depository occasionally of thin 

 veins of the sulphurets of lead and zinc. Two localities have been known for many years, 

 namely, Ancram in Dutchess, and Whitecreek in Washington counties. The former is 

 the most important, but has not been profitably worked ; the latter is a very insignificant 

 mine, furnishing only small bunches of ore connected together by very thin strings of the 

 same. 



RANGE AND EXTENT. 



This rock passes not far west of the dividing line between Massachusetts, Vermont and 

 New-York. By townships, we find it passing through Ancram, Hillsdale, Canaan, New- 

 Lebanon, Berlin, Petersburgh, Hoosic, Whitecreek, the west part of Arlington (Vermont) , 

 and onwards in the same range north through the eastern townships of Canada East. 

 After passing through the tunnel of the Western Railroad, where it is at least two hundred 

 and fifty feet thick, we pass a succession of uplifts which bring up this rock in low hills : 

 these continue about four miles. It is evident that here we pass over the same mass 

 several times. But as I have already observed, it may not be found at all at many points 

 in the direction of the strike ; while at other points it seems to expand widely, as between 

 Canaan and West-Stockbridge. It extends two miles west of the New-York State line, 

 upon the Western Railroad, where it is succeeded by the Taconic slate. 



