No. 1.] BAILEY — GRAND MANAN. 45 



distinguished by Prof. Verrill, and described as being unconform- 

 able, correspond to the two belts recognized by Dr. Gesner, and 

 to which allusion has already been made in describing the physi- 

 cal features of the island. That which forms its eastern side, 

 and which was supposed to be the oldest, was found to consist of 

 talcose and clay slates, mostly grayish, but sometimes black, cal- 

 careous grits, altered grey sandstones, the latter by induration 

 sometimes becoming quartzites, or (when impure) imperfect 

 syenites, and at some points black fissile carbonaceous shales ; — 

 the series, as a whole, being highly altered and disturbed, with 

 numerous immense dykes and masses of trap. The sandstones in 

 one case are described as containing vegetable traces. These 

 rocks were found to occupy not only the belt of low land skirting 

 the eastern border of the main island, but also (as far as examined) 

 the adjacent islands, excepting Inner Wood Island, composed in 

 part of conglomerates and red sandstones, possibly of more recent 

 origin, and the outer of the Three Islands, wherein were found 

 beds of crystalline limestone.''"^ The second series, embracing 

 the trappean belt which forms the western side and the major 

 portion of the main island, is described by Prof. Verrill as 

 consisting of thick-bedded, regularly stratified massive rocks of 

 various composition, but mostly amygdaloidal, trap ash, and com- 

 pact quartzose rocks, the beds being in some places nearly hori- 

 zontal, and in others dipping to the W. or S. W. > 10*^ to 20*^. 

 The traps at some points were found to be columnar, while from 

 the cavities of the amygdaloids were obtained calcite, stilbite, 

 apophyllite and other zeolitic minerals. With regard to the age 

 of the two formations thus distinguished. Prof. Verrill makes no 

 reference to that of the former beyond the statement that it is 

 apparently the older of the two, but offers the conjecture that the 

 latter, judging from the fqypearance of the rocks alone, may be 

 of Devonian age. 



In commenting on these observations the author of the Acadian 

 Geology thinks it probable that the outer and older series above 

 mentioned may be either the equivalent of the St. John group 

 (Primordial) or of the Kingston series (at that time supposed to 

 be of Upper Silurian age), and that the traps, with some asso- 

 ciated sandstones, might be Devonian or Upper Silurian. In the 

 geological map accompanyinsj this work these formations are re- 



* Observed also by Dr. Gesner. 



