142 A. Wandke — Intrusive Rocks of 



sists of two formations, the Kittery quartzite d and the 

 Eliot phyllite 6 . No definite age has been assigned to the 

 first group nor can correlations be made between the 

 different members ; the second group, it seems, can be 

 traced to Worcester, Massachusetts, where fossil-bearing 

 rocks, 9 Upper Carboniferous in age, have been found. 

 The writer, however, has been able to trace the Kittery 

 formation only as far as Lowell, Mass. From there on 

 to Worcester, Mass., a distance of 30 miles, glacial 

 material makes it difficult to follow the strata. The 

 rocks at Worcester from which the fossils have been 

 reported are lithologically unlike those of the Portsmouth 

 Basin. In the hand specimen the typical Kittery quartz- 

 ite is almost identical in appearance with the Isleboro 10 

 formation of Rockland, Maine, perhaps of Cambrian age. 

 It would seem, therefore, that until fossils are found 

 within the Kittery formation its age must remain a 

 matter of inference. The Kittery and Eliot formations 

 are however provisionally dated as Carboniferous, follow- 

 ing the lead of the U. S. Geological Survey. 



Metamorphic Rocks of Unknown Age. 



General Statement. — This classification includes the 

 Gonic schist and the Berwick gneiss which form the north- 

 western boundary of the basin, and the Rye gneiss on the 

 southeastern side. Limits have been assigned to the 

 extent of these formations with the understanding that 

 they are not to be regarded as fixed. 



Gonic Schist. — The Gonic schist has been named from 

 the typical exposures occurring in the falls of the Cocheco 

 River at Gonic, New Hampshire. The rock is a biotite- 

 garnet schist evidently produced by dynamic and 

 contact metamorphism of argillaceous and arenaceous 

 sediments. Cutting across the schistosity of the forma- 

 tion, although occasionally paralleling the same, are a 

 great many stringers of coarse pegmatite and veins of 

 quartz. It is entirely probable that these stringers and 

 veins are genetically related to the intrusive pegmatitic 



d The same as the Katz 's Kittery quartzite. 

 e Is the Eliot slate of Katz. 



9 David White, Jour. Wash. Acad. Sci., p. 115, 1914. 



10 U. S. Geol. Survey, Folio 158, 1908. 



