42 L. W. BAILEY ON THE PHYSIOGRAPHY AND 



grey sandstones, which are banded with paler layers, containing thin beds of grit with 

 crinoids, but in part also of fine, bluish-weathering slates, both being of decidedly Silu- 

 rian aspect. 



About two or two and a half miles aboA^e the movith of Beaver Brook, the sandstones 

 and slates above noted are followed by great masses of very coarse conglomerate, filled 

 with large, well-rounded pebbles of metamorphic rocks, as well as some composed of 

 another conglomerate, imbedded in a thin, sandy paste, and which include sandy beds a 

 foot or more wide, dipping very regularly S. 60° E. < 50°. These conglomerates are also 

 well-exposed upon the Ashland Road, and large boulders, derived therefrom, are strewed 

 over all the surrounding country. Their position, as seen on the last-named road, is pro- 

 bably beneath the sandstones, and they are remarkable in containing nvimerous fragments 

 of black, siliceous slate, with others of green, jaspery slate, features in which they strongly 

 resemble the conglomerates of the Fish Eiver section, as they do others believed to hold a 

 like position on Beccaguimic River, in Carleton County, New Brunswick, on Siegas River, 

 in the same Province, and on Lake Temiscouata, in the Province of Quebec. 



Half a mile below the above exposures, sandstones again come out in high bluffs upon 

 the right bank of the stream, and are probably a portion of the same belt as that first 

 noticed. Here, however, they are remarkable for their massive character, for their low 

 dip (S. < 5-10°), and for their peculiar aspect, being conspicuously filled with little black 

 specks, some of which are, undoubtedly, fragments of black slate, but of which others 

 appear to be fragments of plant remains. They also contain fragments of dark-green ser- 

 pentine. Besides the doubtful impressions referred to, the rock contains numerous, and in 

 in some instances well-preserved, shells and corals. In a collection here made, Mr. Ami 

 has recognised the following : — 



■'s^ 



Impression of a Coral resembling Favosites. 



" " Bryozoon, probably Callopora. 



Orthis, sp. 

 Strophomena subplana ? Conrad. 

 . " rhomboidalis, Wilckens 



Ehynchonella, sp. 



Spirifera, iq^. {Hlr S. radiata, Sowerby.) 

 Atrypa reticularis, Lin. 

 Cornulites (lil:e C. flesuosus, Hall.) 



Mr. Ami regards the above fossils as of about the age of the Niagara or Wenlock, in 

 which case their position' would be below the Lower Helderberg limestones of Ashland, but 

 neither the stratigraphy of the beds or their contained remains have as yet been sufficiently 

 studied to remove all doubt vipon the subject. That they are Silurian, however, rather 

 than Devonian, as they have been hitherto described, appears to admit of but little 

 question. 



Below the mouth of Beaver Brook, Aroostook River exhibits several abrupt changes 

 of direction, and thus alternations of what are probably the same beds are several times 

 repeated along its banks. They include ledges of conglomerate and sandstone, similar to 

 those above described, followed by dark, bluish-grey slates, which, at the southern point of 

 the chief bend in the stream, shew a broad low anticlinal, one hundred yards in length, 

 with a dip in either direction of not more than two or three degrees. Somewhat lower, 



