BULLETIN OF THE GEOLOGICAL SOCIETY OF AMERICA 

 Vol. 34. pp. 419-430 September 30, 1923 



SOME STRUCTUEAL FEATURES OF THE PLAINS AREA OF 

 ALBERTA CAUSED BY PLEISTOCENE GLACIATION ^ 



BY OLIVER B. HOPKINS 



{Read before the Society December 30, 1922) 



CONTENTS 



Page 



Introduction 419 



Description of region 420 



Mud Buttes 421 



Evidence of surficial nature of disturbance 424 



Evidence of tlirusting force j 426 



Development of complex structure by movement of ice-slieet 428 



Summary 429 



Introduction 



Some anomalous structural features in the Great Plains area of Alberta 

 have been known for a long time^ but in recent years they have come into 

 considerable prominence because of the prospect of commercial oil pools 

 being associated with them. The study of one of the most conspicuous 

 of these supposed uplifts, together with the result of wells recently drilled 

 in the vicinity, indicate fairly conclusively that there has been no uplift- 

 ing of the formations in the area, and that the abnormally steep dips and 

 local folds and faults are the result of the thrust of the great ice-sheet 

 which moved southward over this area in Pleistocene time. 



The object of this paper is to demonstrate, if possible, two points, 

 namely : 



(1) That the intense deformation of the beds observed at Mud Buttes 

 and similar localities is entirely superficial and without deep-seated sig- 

 nificance and in no way connected genetically with tectonic disturbance 

 of the region. 



(2) That the abnormal surficial disturbance of the strata was caused 

 by the movement of the continental ice-sheet against conspicuous pre- 

 glacial hills. 



1 Manuscript received by the Secretary of the Society January 15, 1923. 



(419) 



