20 W. H. Twenhofel — Physiography of Newfoundland. 



data to discuss the occurrence of this level in other parts of 

 Newfoundland. 



Scarp of the Long Range and the foreland. — These two 

 features seem to be causally related in their method of origin 

 and so are considered together. The absence of detailed facts 

 relating to the sediments along the entire base of the cliff 

 renders any conclusion merely tentative. The facts at present 

 known to the writer suggest an origin for each in two possible 

 ways, one far more plausible than the other. These are dis- 

 cussed in succeeding paragraphs. 



(1) It may be assumed that the foreland is a plain resulting 

 from marine erosion. The presence of terraces up to 400 feet 

 shows that at one time sea waters covered such portions as are 

 below this elevation. These waters were, however, post-glacial 

 while the foreland's surface existed in pre-glacial time. The 

 general limitation of the foreland to the sediments and its 

 absence when the crystallines are reached favor the idea of its 

 production by marine erosion, which is not supported, however, 

 by the fact that at least three large blocks of the sediments — 

 Anguille Mountains, St. John Mountains, and Portland Head — 

 are left standing on the plain and reach the sea. Its extreme 

 variability in width and almost total absence where the line of 

 cliff reaches the sea, no matter of what kind of rock it be com- 

 posed, and the steepness and well preserved character of the 

 cliff face in view of the great age required on the assumption 

 of marine erosion render the hypothesis untenable.* 



(2) It may be assumed that the scarp is a fault face along 

 which the present Long Range has been elevated. The facts 

 practically proving this idea are : the localization of numerous 

 intrusions along the foot of its southern extension, its remark- 

 able integrity, the actual presence of great faulting near its 

 base at several widely removed localities, and the upturning of 

 the beds where these have been observed at the base of the 

 cliff. The horizontally of the beds, except in the immediate 

 vicinity of the intrusive masses, and their occasional dip 

 toward the mountains find in this idea a ready explanation. 

 On this idea the elevated blocks on the foreland and its varia- 

 tion in altitude are merely due to differential subsidence and 

 elevation, while the bays of St. George and St. John are 

 masses in which the depression was somewhat greater than 

 .the rest of the surface, the straight northern coast of St. George 

 being the bounding fault of this bay, which, continued inland, 

 fixed the course of the St. George River. The upper portion 

 of the cliff face, that in which the elevated valleys have been 



* This hypothesis permits the assumption that the Long Eange may be 

 anticlinal in character. A search for data supporting this assumption 

 yielded negative results. 



