granitic: REGIOiy, 



From the wliole ol his descriptit^n, it follows, that 

 the region of these calcareous stones, which we shall 

 fend prevailing every where west of the AlleghanieS) 

 extends in a line north-west beyond Lake Michigan 

 as far as the sources of the Mississiopi, and thence 

 to those of the Saskachawan, thus joining the grtind 

 fihain of the Stony or Chipewan mountc>ins, which is 

 itself a continuation of the cordillera of the Andes i 

 ^' and it must be observed," says Mr. Mackenzie, 

 that all the great lakes of North America are placed 

 in the line of contact between these vast chains of 

 granite and of limestone.'' This is a fact in physics*^ 

 that merits the attention of the philosophical geolQ- 

 gist. 



Returning to the southward from the river St» 

 Lawrence, granite prevails throughout Steuben coun- 

 ty, as flir as the M ohawk, the course of which it 

 accompanies, though I cannot affirm, th it it crosses 

 it, except at its htrle fall above Skenectady. We 

 see none at its great fall, that of Cohoz, the beci of 

 which is a serpentine, of the same species as I found 

 at Monticello in Virginia, a species very widely 

 diffused throughout the whole of the chain called 

 South-west Mountain ; but it reappears immediately 

 below Albany, on the east bank of Hudson*s River, 

 which cfjnstantly Hows between two rugged declivi** 

 ties, covered with thin copses of oaks and firs.* 



• Mr, Volney says that the bed of the Mohawk appears to separate 

 the granite from the sandstone country : but the editors of the Me* 

 dical Repository say, this is a mistake, for there is no granite tos. 

 wards the north on the east of the Hudson, in New York ; c xcept in 

 that tract called the Oblong or on the western line of Connecticut. 

 Along the eastern pait of New York, and western part of Massach^j. 

 ittts, ther»ck is «*46*r^ous> extending from Stockhridge to Verrpofet. 



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