492 W. H. HOBBS — LINEAMENTS OF ATLANTIC BORDER REGION 



Carolina coastline and southern fall line. — Parallel to the northern fall 

 line above referred to runs for about 400 miles the gentl} 7 escalloped coast- 

 line of the Carolinas (J). Almost exactly midway between it and the line 

 H is found a parallel line of the series (I), which is hardly less marked 

 than the first described, and for the similar reason that it is in coincidence 

 with the southern fall line from near Raleigh, North Carolina, south- 

 westward through Augusta to Macon, Georgia. As subsequently shown 

 by the geological survey of Georgia, this fall line continues beyond 

 Macon to Columbus, on the border of Georgia and Alabama.* The 

 margin of the Eocene deposits with the crystallines (see course of dotted 

 line in plate 46) is along this line, only less in coincidence than was the 

 Cretaceous-crystalline border with the first described line of this series 

 (H). Where the Eocene is covered by Quaternary deposits near Augusta 

 the fall line has been assumed to be near the course of the covered 

 boundary. 



It is worth noting that the southern Newark areas are largely enclosed 

 between the lines H and I, which the eastern and western belts of that 

 system approach respectively. It may also not be without significance 

 that the almost constant dip of the beds in the western chain of areas 

 (Dan river, Danville, Richmond, etcetera) and the Nova Scotian area are 

 to the westward, whereas the eastern series (Wadesboro and Deep River 

 areas) have dips to the eastward. These dips are for the most part from 

 15 to 28 degrees except near the western boundary line, where they either 

 change direction or become steeper.f To the west of the line H the 

 irregular outline of the Newark areas corresponds to marked changes in 

 the dip. In the Connecticut and Pomperaug Valley areas, however, the 

 dips are uniformly southeastward or toward the larger dislocations. 

 These dip measurements, when constant over large areas, are believed 

 to afford valuable data regarding the tilting of the blocks, since folding 

 is practically absent from them. The marked irregularity in dip and 

 its higher angles, as has been said, doubtless indicate the proximity of 

 a main line of dislocation. In this connection the statement of Russell 

 concerning the supposed synclinal structure of the bay of Fundy is not 

 without interest : % 



* Thomas L. Watson : A preliminary report upon a part of the granites and gneisses of Georgia. 

 Geol. Survey Georgia, Bull. 9 A, 1902; plate opposite p. 88. 



f " In the Dan River area, especially, the high dip of the Newark system, amounting in many 

 instances to nearly 50 degrees within a few rods of the line of junction with the crystalline rocks, 

 is a very strong indication of marginal faulting." 



"The Danville and Dan River areas are remarkable for the high inclination of the strata com- 

 posing them. In many places, throughout continuous sections over a mile in length, the beds 

 have a persistent western dip at angles varying from 35 to over 50°." I. C. Russell : The Newark 

 System. Bull. 85, U. S. Geol. Survey, 1892, pp. 85 and 86. 



| Loc. cit., p. 80. 



