420 O. B. HOPKINS STRUCTURAL FEATURES OF PLAINS OF ALBERTA 



The writer acknowledges with pleasure the cooperation of Dr. J. S. 

 Stewart in the development of the ideas herein set forth and his help in 

 the preparation of this paper. 



Description of Eegion 



The area in which the abnormal structures are found is in the plains 

 region of east-central Alberta (see accompanying sketch, figure 1). Ab- 



FiGURE 1. — Deep Wells of east-central Alberta^ xcestern Saskatchewan 



normal dips are found at many places in that region; but the complex 

 structures, to be described later on, are found in two principal groups of 

 hills, namely Tit Hills and Mud Buttes. The former are located 10 

 miles south of Czar and the latter 9 miles south of Monitor. In most 

 of the hills of the region abnormal dips are in evidence, due either to 



