﻿JV. S. Shaler — Geology of Cobscook Bay District, Me. 47 



faulting occurred. This fact seems to indicate that the source of 

 supply of this volcanic material was very near the level of the 

 rocks, so that no fissure of any size could form without giving 

 exit to igneous matter. This may perhaps be explained by the 



11. 



Horizontal and vertical section of small fold on shore 2^- miles N.W. of Red Island. 



A, A, trappean rocks, 

 section 200 ft. long. 



B, B, reddish and greenish shales. X — T, line of 



12. 



fact that the rocks of this region were very near the seat of 

 extensive and long continued volcanic action which naturally 

 led to the formation of a very large supply of rock matter in 

 the state to be forced into every crevice which penetrated to it. 



The almost invariable dip toward 

 the east and southeast exhibited by 

 the masses of stratified rocks in this 

 district is a very remarkable feature 

 in its structure, one for which I have 

 no explanation to offer. Near N - w - endot " M ° ose island.. 



Extending our observations beyond A » hard M SSY slates. B, vol- 



,i I j? rt u i. b.„ m „fi„j came ash. C, slickensided 



the shores of Cobscook Bay, we nnd conlact 

 in the shores of Passamaquocldy Bay a 



considerable change of structure. The islands of Campobello 

 and Deer Island have the general structure of anticlinals, the 

 basin between them, known as Quoddy river, being distinctly 

 synclinal in structure. These islands are in the main composed 

 of a series of very compact and highly metamorphosed, non- 

 fossiliferous schists, slates, and quartzites considerably cut by 

 dykes, which in the main apparently belong to an older series 

 of extrusions than those which intersect the fossiliferous rocks. 

 These rocks, which for convenience may be termed the Campo- 

 bello series, are clearly several thousand feet in thickness. 

 They have disclosed no fossils, although a careful search has 

 been made for them. An assistant of the present writer, Mr. 

 G. H. Squier, a very acute observer, spent several months in a 

 detailed study of the geology of the island of Campobello 

 without finding the least trace of fossils in the abundantly ex- 

 posed beds. The entire absence of limestones, or beds of a 

 calcareous nature, is sufficient to show that they cannot be re- 

 garded as the metamorphosed equivalents of the Cobscook series. 

 The general absence of lime from this Campobello series is 



