Section IV, 1919 [17] Trans. R.S.C. 



The Delta of the Little River Group and Some of its Peculiarities 



By G. F. Matthew, D.Sc, F.R.S.C. 

 (Read May Meeting, 1919.) 



This paper deals more at length with some pecuHarities of a 

 deltaic deposit described in a former article read before this Society 

 and one communicated to the Natural History Society of New Bruns- 

 wick^ In the following notes the subject is treated more at length, 

 specially in relation to the source of the sediment which built up the 

 Cordaite deposit. But as a preliminary to what is there stated, one 

 may mention that the source and course of a river in the Cordaite 

 period is not yet known; that a delta existed, however, may be in- 

 ferred from what is stated below. 



Very little is known of the history of land-deltas of this early 

 time. The changes in the level of the land have been so great, and the 

 erosion of the earth's surface so enormous during the ages that inter- 

 vened between that time and the present, that seldom or never can 

 the connection between the sources and the delta of a river of that 

 age be found. Still, one should have clearly in his mind, the fact that 

 a complete river system should have three principal parts. 



There are first, the sources which are usually in some mountain 

 system, or some high table-land; second, the river valley, usually 

 eroded considerably below the chain of hills or ridges that bound the 

 valley on either side; and third, the delta or terminal plain, where the 

 river enters the sea. 



In such cases as that here considered, only the delta remains to 

 tell the history of past geological changes, and to give hints of con- 

 ditions on the neighbouring emerged land, at least this delta is all 

 that we have to tell of terrestrial conditions in Silurian times at St. 

 John and its neighbourhood. 



Whenever, because of pressure from the ocean abysses the con- 

 tinental border was raised, erosion of the land-area occurred, and the 

 river valleys suffered from erosion not infrequently they were com- 

 pletely obliterated or disconnected, and in this way the source of 

 the river could be entirely cut off from the delta which it had formed. 

 This appears to have been the case with this old delta at St. John 

 which in this way was completely cut off from the source of its sedi- 

 ment which may have come from the great Pre-Cambrian area, which 

 then appears to have had a great extent in eastern New Brunswick 



1 Bull. Nat. Hist. Soc, N.B., No. XXXII, 1918. 



