264 SMYTH — ROCKS OF NORTHWESTERN ADIRONDACK REGION. 



Introduction. 



Since the publication of the report of Emmons on the geology of the 

 second district of New York, the northern and western portions of the 

 Adirondack region have received little more than casual mention in 

 geologic literature. This is even more markedly true than in the case 

 of the eastern counties, though little enough has been done there until 

 quite recently. 



Having spent some time in the contiguous portions of Saint Lawrence, 

 Jefferson and Lewis counties, the writer has ascertained certain facts 

 which may be taken as a starting point for an inquiry into the geologic 

 relations of the region. Although but little more than a beginning has 

 been made, it seems expedient to present some of these facts with the 

 conclusions drawn from them, particularly to establish a basis of com- 

 parison between the phenomena exhibited in different portions of the 

 Adirondack region. With this end in view it is proposed to give a con- 

 densed description of the limestones themselves, with a more detailed 

 account of those other crystalline rocks of the region whose character 

 and relations to the limestones are pretty clearly established. 



Extent and Character of the Limestones. 



There is a marked contrast in the extent of the limestones between the 

 region described by Professor Kemp in the preceding paper and that now 

 under consideration. In Essex county they form rather limited patches, 

 while in Saint Lawrence, Jefferson and Lewis counties they constitute 

 extended belts many square miles in area. For instance, a limestone 

 belt begins near the village of Antwerp, and extends eastward across the 

 township of that name, across Rossie and Gouverneur, into Hermon. 

 This belt has been traced more than twenty miles along the strike, while 

 the average width is perhaps six miles. A narrower belt extends across 

 Fowler into Edwards township, and is distinguished by containing 

 extensive talc deposits. Farther to the south, a third belt of limestone, 

 that appears from beneath superficial deposits which probably hide an 

 extension westward, begins just west of the village of Natural Bridge, 

 Jefferson county. This belt crosses the townships of Diana, Lewis 

 county, and Pitcairn, Saint Lawrence county, with an average width of 

 two or three miles, narrowing toward the east and passing into Edwards. 

 No extended belt is known farther south, though this may be due to the 

 fact that in this direction there is a dense and unfrequented forest ; but 

 scattered patches of limestone have been noted in various portions of 



