BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 

 Vol. 34. pp. 561-572 September 30, 1923 



CEETACEOUS AGE AND EAELY EOCENE UPLIFT OF A 

 PENEPLAIN IN SOUTHERN BRITISH COLUMBIA ^ 



BY W. L. UGLOW 



{Presented 'before the Society December SO, 1922) 



CONTENTS 



Page 



Statement and solution of the problem 561 



Location 562 



Topography of the trench 562 



General geology of the trench 564 



The rock formations 564 



Pre-Tertiary complex 564 



Tertiary rocks 564 



Post-Tertiary rocks 566 



Cretaceous peneplain , 567 



Early Eocene uplift 568 



Middle to Upper Eocene sedimentation 568 



Oligocene diastrophism and erosion. 569 



Block-faulting 569 



Miocene vulcanism 570 



Post-Miocene diastrophism and erosion 570 



Pleistocene glaciation and subsidence 571 



Recent uplift, erosion, and vulcanisjn 571 



Statement axd Solutioj^ of the Problem 



During a detailed geological survey of the North Thompson Valley 

 map area- in south-central British Columbia, carried out for the Geo- 

 logical Survey of Canada during the summer of 1921, the writer was 

 fortunate enough to encounter certain highly fossiliferous members of 

 the early Tertiary coal-bearing beds which lie at the bottom of the North 

 Thompson River trench from 40 to 55 miles north of the city of Kam- 

 loops. In the hope that the topographical location, structure, and age 



1 Manuscript received by the Secretary of the Society November 6, 1922. 



Published with the permission of the Director, Geological Survey of Canada. 

 - Summary Rept., Geol. Surv. Canada, part A, 1921, pp. 72-106. 



XXXVII — Bull. Geol. Soc. A.m.. Vol. 34. 1922 (561) 



