[MATTHEW] THE DELTA OF THE LITTLE RIVER GROUP 19 



where they overHe unconformably the more highly-disturbed strata 

 of the Little River group. 



Lowest among these Upper Silurian strata is the Bloomsbury 

 effusive series which either in the form of unaltered lavas and ash 

 rocks, or as reddish and greenish-grey, stratified rock, are found mostly 

 at the margins of the basins, and tell of the way in which the accumu- 

 lation of these rocks began. A large mass of these effusives 

 forms the prominent hill on the west side of St. John harbour. An- 

 other volcanic mass is Partridge Island at the mouth of St. John 

 harbour; another, the Manawagonish Islands, is on the same line of 

 vents. Similar intrusives mark the southeastern side of the basin of 

 these rocks. 



The group which immediately overlies these volcanic strata are 

 the quite dissimilar beds known as the Dadoxylon sandstone in which 

 the oldest plant remains of the Silurian succession at St. John are 

 found. The source, course and termination of the river courses of this 

 set of beds is fairly well shown, but that of the overlying Cordaite 

 slates and sandstones is not so apparent. 



The Cordaite beds were laid down like their predecessors in what 

 are now narrow parallel valleys of which that of the Little River basin 

 is the principal one, and, so far as is at present known, were deposited 

 in fresh water, since plant remains and denizens of the fresh- waters 

 and the land are the only remains of living objects found in the slates 

 and sandstones of the Cordaite series. 



Assuming then, that the sources of the sediment which built up 

 the Dadoxylon beds is fairly well known, there remains a considera- 

 tion of the origin of that which has built up the many feet of strata 

 which constitute the Cordaite group, so uniform in character, and so 

 far as we know, in its most complete basin, quite devoid of marine 

 strata. In this connection one may well consider the known Silurian 

 deposits of this region and their characteristics. So far as known, 

 we have no "abyssal" deposits, but there is a large area extending 

 southwestward into New England, between Gaspé, in eastern Quebec 

 on one hand and the main peninsula of Nova Scotia on the other, where 

 extensive shallow-water marine deposits are known. At irregular 

 intervals along the southern side of this tract are detached basins 

 which by the presence of land plants, terrestial animals or fish remains, 

 indicate the nearness or actual presence of emerged land. Farther to 

 the southwest, we lose even these indications of the vicinity of the 

 land to the sea margin, and there is nothing in the present condition 

 of the earth's surface there to show whether the area beyond the 

 present sea shore had emerged land or was beneath the sea. Jas. D. 



