52 AN OUTLINE OF THE 



to have been originally stratified sedimentary deposits ; but 

 their texture has become' crystalline by long continued 

 change, and hence they are to be regarded as extremely 

 ancient. It is probable that a search on the neighboring 

 mainland will enable us to define more precisely the rela- 

 tive age of the schists by means of their contact with the 

 other old rocks ; and when this is done, we may expect to 

 find proof, not only that the schists are the oldest of the 

 series, but that after the deposition of their sediments they 

 were buried deeply enough for metamorphism into their 

 present crystalline structure, and then greatly denuded 

 before any other rocks were formed in this region. They 

 will then be seen to be older than the other rocks by a 

 great interval of time. The rocks of Schooner Head and 

 of a limited stretch of the eastern coast may perhaps be 

 classed with the greenish schists of Bartlett Island; but 

 their age is not well determined. 



On the southern and northeastern sides of the Island, 

 and on some of the adjacent smaller islands, as Bar Island, 

 the Porcupines, and Sutton Island, there are many ex- 

 posures of a series of bedded rocks, partly slates, partly 

 sandstones and flagstones. These are manifestly sedi- 

 mentary deposits in ancient seas. They are of firm 

 texture as a rule, although some of the layers are weak 

 enough to undermine the overlying beds and form dis- 

 tinct ledges, as near Bar Harbor landing. Sometimes 

 there are fine pebbly layers, with grains of white quartz, 

 as on the shore near Northeast Harbor. The greater 

 part of this series is well indurated ; but otherwise it has 

 suffered little structural change since its deposition. In- 

 deed, if any fossils had originally existed in the beds, they 

 should be still observable, but none have yet been found. 

 The strata generally dip away from the granitic belt ; and 

 on the Cranberry Isles their inclination is nearly vertical. 

 The granite cuts them in various places, and frequently 



