QUEEN CHARLOTTE ISLANDS. 47 B 



have evidence of the occurrence of a period of great volcanic activity, Cretaceous 

 which led to the intercalation of several thousand feet of almost unmixed roc 

 volcanic products. Following this, without any marked unconformity 

 was a tranquil period, during which a great thickness of shales and 

 shaly sandstones was deposited, and in connection with the earliest 

 beds of which the Skidegate coal was formed. The overlying con- 

 glomerates probably evidence a period of depression, after which, and 

 closing as far as we know the record of the Cretaceous period in this 

 region, an upper series of shales and sandstones was produced in a 

 shallow and quiet sea. The great period of disturbance and mountain dfsturbanc^ eat 

 formation for the region now supervened, and the only record we have 

 of the time easing between the Cretaceous and later Tertiary is in 

 the flexure, crumpling and fracture of the beds. 



It would seem that during the portion of the Tertiary period repre- Conditions dur- 

 sented by the rocks of the north-eastern portion of Graham Island, the period rtiary 

 general relative level of sea and land has not been far different from 

 that now obtaining. Wide areas, probably including much swampy 

 land, were covered with a dense vegetation which in favourable cir- 

 cumstances gave rise to lignite deposits. There may have been several 

 minor alterations of level, of one of which we have evidence at Skon-un 

 Point, in the stratum with marine shells which overlies the lignites. 

 The records of the period are closed by the great volcanic flows which 

 were probably supplied by a number of different centres of eruption 

 the approximate positions of some of which are shown by the coarse 

 agglomerate beds. 



Notes on the Map. 



The older rocks of the islands, coloured as Triassic, are placed in this Map. 

 division on the evidence and with the reservations above detailed. 

 Those coloured as Cretaceous constitute the coal-bearing series of 

 Skidegate, and have sometimes been referred to the Jurassic period, 

 though Mr. Whiteaves, on more detailed examination of the fauna, is 

 inclined to place them in the Cretaceous. The Tertiary rocks are 

 chiefly volcanic, and are supposed to stretch below the low north- 

 eastern part of Graham Island, beneath the drift covering. The 

 fossils discovered are not sufficient clearly to prove their Miocene 

 age, but they are classed provisionally as Miocene, as they represent 

 with little doubt, rocks which have been attributed to this period on 

 other parts of the "West Coast. It should also be remembered, in con- 

 sulting the map, that while the divisions are drawn with sufficient 

 accuracy on those parts of the coast which have been surveyed and 

 examined, the continuation of the lines inland is based on the attitudes 

 of the rocks and physical character of the country alone, and that 



