252 ON THE GEOLOGY OF ST. JOHN. 



band of dark red slates, probably representing the upper division. 

 Beds of dark shale, which are intercalated with the sandstones, 

 hold stems and other fragments of plants. 



The upturned edges of these rocks, so remarkable for the abun- 

 dance and perfection of the flora which they contain, have thus 

 been traced around a double curve from Manawagonis to Black 

 River, a distance of more than thirty miles and therefore spread 

 over ao area of sixteen miles in breadth. 



On a grey slate, just above the most prolific plant-bed at Duck 

 Cove, distinct rain marks like those obtained from the red sand- 

 stones of Connecticut were observed. 



It will be observed that from the base of the Bloomsbury 

 group to the top of this sandstone there is a series of deposits sim- 

 ilar to those of the Coldbrook group, viz., volcanic sediments, 

 red slates and conglomerates, grey sandstones. 



h. Cordaite shales. — At the locality north of Mount Prospect, 

 there is an excellent exposure of this as well as the lower division 

 of the Little River group. By increase in the bulk and frequency 

 of the finer beds, the sandstones gradually pass into arenaceous 

 shales of greenish, grey and red colours, which frequently alternate 

 with reddish and grey sandstone and grit,* the latter predomina- 

 ting east of this place, while the shales are more prevalent in the 

 western extension of the deposit. Near its upper limit it ap- 

 proximates in the increase of coarser sediments to the lower 

 beds of the Mispeck group ; from these, however, the older con- 

 glomerates are easily distinguished by the small size, great num- 

 ber, and roundness of the quartz pebbles. Cordaites Robbii has 

 been found to characteriza these shales throughout nearly their 

 whole thickness of 2300 feet. They cover an extensive area in 

 the valley of Mispeck River, owing principally to a secondary fold 

 in the strata (see section). 



A thick series of micaceous slates and imperfectly formed gra- 

 nites and granulites or granitic sandstones with beds of trap-ash, 

 conglomerate grit and limestone occur on the Bay shore at West 

 Beach and Black River ; and with their contained minerals are 

 described in 3rd Report on Geology of New Brunswick. At the 



* In two-thirds of the thickness of these shales there are thirty-seven 

 distinct alternations of these coarser beds with the shales, varying from 

 two to forty feet in thickness. In the upper third the sandstones be- 

 come redder, and some thick beds of a coarser conglomerate appear. 



