154 



the deformation of the bedded rocks seems to have con- 

 sisted in warping and normal-faulting, especially the latter. 

 The extremely abundant sills and other intrusive bodies 

 have suffered nearly as much deformation as the invaded 

 sediments. 



The Western Geosynclinal Belt is structurally the most 

 complex of the three principal provinces. All of its bedded 

 formations, from the Carboniferous to the Cretaceous 

 inclusive, are more or less intensely folded. The thick 

 Carboniferous group has been specially affected by close- 

 folding and mashing, with resulting turmoil in most of the 

 Carboniferous areas. 



Rocks of the Beltian to the Mississippian, inclusive, are 

 only locally represented in this province, which except for 

 limited areas was clearly a region of erosion during that long 

 period. In our section the oldest known Paleozoic strata 

 are Carboniferous (Pennsylvanian) in date. These lie 

 unconformably upon the Shuswap terrane. A second 

 unconformity is well exposed between the Pennsylvanian 

 limestone and the Triassic near Kamloops. A third 

 exists at the base of the Lower Cretaceous; a fourth at the 

 base of the older Tertiary (Eocene?) geosynclinal deposits 

 of the Strait of Georgia and Puget sound. An unconfor- 

 mity is registered at the base of the Oligocene in the 

 Interior Plateaus and it probably corresponds to a defor- 

 mation of post-Eocene date. A sixth unconformity is, 

 of course, seen at the contact of the Pleistocene deposits 

 with older formations. 



NOTE ON THE IGNEOUS BODIES. 



The sedimentary rocks of the Eastern Belt are, in our 

 section, very seldom interrupted by igneous masses. 

 The remarkable Ice River intrusion (see page 185) and the 

 contemporaneous lavas in the Cougar formation (see page 

 136) are the only important eruptions observed in the 

 railway zone between the Great Plains and the heart of the 

 Selkirk range. On the other hand, the Western Belt 

 shows not only a much larger number of unconformities, 

 but also an incomparably greater amount of igneous acti- 

 vity. 



Following the rule illustrated throughout the world, the 

 downwarping of the western geosynclines has been 



