BY L. KEITH WARD, B.A., B.E. j^j 



necessarily follows that the great series of qtiartzites 

 and conglomerates must be of Cambrian (or even pos- 

 sibly of Pre-Cambrian) age. 



Confirmatory evidence again is afforded by the ap- 

 parent relationship of the West Coast Range conglome- 

 rate to the Dundas slate series (2). 



Moreover, the porphyritic igneous rocks, which are 

 partly contemporaneous with these Dundas slates, have 

 never been seen in the form of pebbles in the West 

 Coast Range conglomerate. Diligent search has been 

 made by the writer in localities where the two rocks 

 are in the closest proximity, and always without finding 

 any rounded pebbles of the porphyries, or the schists 

 derived from them, in the conglomerate. This seems 

 to him to be highly significant, although negative 

 evidence. 



Again, certain structural phenomena are more 

 readily explicable by the view that the porphyries have 

 intruded into the conglomerate beds, rather than that 

 subsecjuent complex faulting has produced the isolation 

 of blocks of the sediment within the igneous boundaries. 



At Railton, the pebbly sandstone and conglomerate 

 appears, from its position, to underlie the Caroline 

 Creek fossiliferous sandstone. 



The relation of the Caroline Creek beds to the 

 Dundas slates has not yet been determined, so that a 

 complete chain of evidence regarding the exact age of 

 the conglomerates and the slates has not yet been ob- 

 tained. 



No fossiliferous zone which may serve as a line of 

 demarcation for the base of the Cambrian system has 

 yet been detected. 



Our knowledge at the present time is such that it 

 seems advisable to include the Denison Range and West 

 Coast Range conglomerates within the Cambrian sys- 

 tem, of which they would therefore seem to form the 

 base. 



5. In the vicinity of Beaconsfield a series of sand- 

 stones, quartzites, slates, grits, and conglomerates are 

 found to dip under the Ordovician limestone, which lies 



(2) See Section JV. 



