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NEW YORK STATE MUSEUM 



believed to be augite-syenite, was plainly intrusive in the 

 anortbosite at that point and hence younger. No other contacts 

 could be found. Some territory, previously unvisited, was 

 mapped. Next a section was run across the main anortbosite 

 mass from Blue pond on the New York and Ottawa railroad to 

 Saranac, by way of Saranac Inn. Except for frequent dikes of 

 granite and gabbro, the anortbosite extends unbroken from one 

 locality to the other. It had previously been assumed to do so 

 from its occurrence at the two extreme points. Incidentally, 

 interesting observations were made on the topography of the lake 

 belt, and some evidence of the existence of a large glacial lake 

 in the belt was gathered. 



The remaining time was utilized in detailed work in that part 

 of Clinton county which is comprised in the southern half of the 

 Mooers quadrangle of the topographic atlas, constituting por- 

 tions of Chazy, Beekniantown, Altona and Dannemora towns. 

 Formation boundaries were mapped in detail and progress made 

 in mapping the glacial deposits of the district. A detailed report 

 of the results obtained is given hereafter, and the economic 

 geology of the area is also discussed. Quarries have been 

 recently opened on Rand hill and Dannemora mountain, and a 

 boring for oil is in progress at Morrisonville. 



The region studied by Prof. C. H. Smyth jr embraces the town 

 of Alexandria and parts of Clayton and Theresa in Jefferson 

 county, together with parts of Rossie and Hammond in St Law- 

 rence county. Within this area are included the well known 

 Thousand islands of the St Lawrence river. The rocks of the 

 region consist of a continuation of the crystalline rocks of the 

 Adirondack region together with the Potsdam sandstone in large 

 amount. 



The crystalline rocks, which were the main object of study, 

 show the various types found farther south, which have been 

 described in previous reports. The crystalline limestone group, 

 or Oswegatchie series, of this and previous reports is exhibited in 

 great variety, showing many schistose members and, what is rare 

 elsewhere, heavy masses of vitreous quartzite. This formation is 



