SUMMARIES OF CURRENT NORTH AMERICAN PRE- 

 CAMBRIAN LITERATURE. 1 



Smyth 2 reports on the crystalline rocks of St. Lawrence county, 

 and particularly the towns of De Peyster, De Kalb, Hermon, Edwards, 

 Canton, Russell, Potsdam, Pierrepont, and Parishville; together with 

 points reexamined in the towns of Gouverneur, Rossie, and Fowler, 

 which were covered in the examination made during 1893. The 

 crystalline limestones, for which, in a previous report, the name 

 Oswegatchie series was suggested, form belts stretching in a north- 

 east-southwest direction. Four belts comprise a large proportion of 

 the crystalline limestones of the region examined. The largest, the 

 Gouverneur belt, extends from Antwerp to probably two miles south 

 of Canton village. Northwest of this belt another belt extends from 

 Theresa, across Rossie and Macomb, into De Peyster. This belt is 

 perhaps separated from the first belt by narrow strips of gneiss, along 

 the northern boundary of Gouverneur, although the precise extent of 

 the gneiss belts is undetermined. The third belt, the Edwards belt, to 

 the south of the Gouverneur belt, and separated from it by a belt of 

 gneiss, begins in Fowler, crosses Edwards, and runs out in the western 

 part of Russell. The fourth belt, the Diana belt, south of the Edwards 

 belt, and separated from it by gneiss, crosses the towns of Pitcairn and 

 Diana. In general, the limestones have their greatest development in 

 the northwestern part of the region, decreasing as the eastern and 

 southern parts of the district are approached. 



The limestone is everywhere thoroughly crystalline, ranges in color 

 from white to dark bluish-gray, and often contains disseminated and 

 aggregated silicates, of which the more important are serpentine and 

 tremolite. 



The term gneiss is used to include rocks ranging from acidic to 

 basic, from fine to coarse grained, and from distinctly gneissoid, or 

 even schistose, to entirely massive. They constitute a complex series, 



1 Continued from page 205, Vol. VII., Jour. Geol. 



2 Report on the crystalline rocks of St. Lawrence county, by C. H. Smyth, Jr.: 

 From the Fifteenth Ann. Rept. State Geologist, in Ann. Rept. of N. Y. State Museum, 

 1895, pp. 48i-497- 



406 



