ON THE GEOLOGY OF ST. JOHN. 251 



by the forks of Black River, there are subordinate ridges of a 

 dark red slate, capped by heavy beds of reddish conglomerate 

 having a thickness of 2000 feet. 



This thickness decreases so rapidly to the westward, that at 

 Courtney Bay on the east side of the harbour it does not exceed 

 150 feet. 



These sediments constitute a passage from the volcanic beds to 

 the sandstones of the group above. No fossils have yet been ob- 

 tained from them, and as they are thickest where the former are 

 most prominent, they have been grouped as above. 



Little River Group — a. Dadoxylon Sandstone. — This depo- 

 sit in its liihologolical characters and fossils is the most constant 

 and unchanging of the strata which have been shown to be un- 

 questionably of Devonian age, and has been a valuable guide in 

 tracing out the relations of the rocks eastward of St. John. A 

 fine exposure of the whole of this sandstone and the greater part 

 of the upper division of the group may be seen north of Mount 

 Prospect (about four miles east of the city) where they rise from 

 beneath the post pliocene gravel of Little River valley. The first 

 consists of hard grey sandstone, with beds of grit and layers of 

 dark grey shale at intervals, the whole having a thickness of 2000 

 feet. The fossils are Calamites transitionis, and fragments yielding 

 discigerous and other porous tissues. The lower layers can be 

 traced four miles east (to Latimore Lake), where they sink beneath 

 gravel beds in the valley of the Mispeck River. 



On the south side of the valley the sandstones again reappear 

 with a westerly dip. Further down the river the strata incline to 

 northwest and westnorthwest as they approach Port Simonds. 



At the bridge over the Mispeck on Black River road the sand- 

 stone contains fragments of carbonized wood, Calamites transi- 

 tionis, and C. sp. ? A bed of dark shale at the same place holds 

 Cordailes Robbii, C. angustifolia, and a calamite (G. cannaefor- 

 mis ?), numerous stems of ferns and leaflets and broken fronds of 

 two species (one is probably Neuropteris poJymorpha,J)&^ .) A 

 few beds of grey pebble conglomerate occur in the sandstones of 

 this valley, and the thickness of the deposit is much greater than 

 at Liitle River; and further west (being about 3600 feet) an out- 

 crop of grey sandstones, which I have, no doubt belong to this 

 series, was traced for several mi'es along the southeastern side 

 of Bloomsbury axis. They rest conformably on the lower divi- 

 sion of the Bloomsbury group, being separated from it by a thin 



