THE LYMAN SCHISTS OF NEW HAMPSHIRE 381 



morphosed rocks is being transferred from the pre-Cambrain to 

 the Paleozoic, and the origin of the schists is found to be more 

 diverse than was at first conceded. It is in line with these results 

 that the variety and distribution of effusive rocks, both flows and 

 pyroclastics, interbedded with the schistose Paleozoic sediments, 

 are being expanded as investigation proceeds. In a paper written 

 in. 1894, G. H. Williams called attention to this fact. 1 He briefly 

 described the following localities in eastern North America, where 

 volcanic rocks were known at that time: Newfoundland, Nova 

 Scotia, New Brunswick, that part of the province of Quebec lying 

 west of Maine and north of Vermont and New Hampshire, Maine, 

 Massachusetts, Pennsylvania, Maryland, Virginia, and the Caro- 

 linas. To this list it is probable that Rhode Island and New 

 Hampshire may now be added. Williams mentioned New Hamp- 

 shire in his text, but did not show any volcanic rocks in this state 

 on his map. He observed that "in New Hampshire felsites and 

 quartz-porphyries abound. They were regarded as eruptive by 

 Hitchcock and by Hawes when they occur in dykes, although the 

 latter regarded .many of them, especially when interstratified, as 

 sediments fused in situ." 2 This paper by Williams contains numer- 

 ous references. A list of more recent articles on the subject is given 

 by J. E. Pogue, Jr., in his "Geology and Structure of the Ancient 

 Volcanic Rocks of Davidson County, North Carolina." 3 



1 "Distribution of Ancient Volcanic Rocks along the Eastern Border of North 

 America," Jour. Geol., II (1894), 1-31. 



2 Op. tit., p. 24. 



^ Am. Jour. Sci. (4), XXVIII (1909), 218-38. 



