THE TRIASSIC PERIOD. 9 



on the southeast by younger (Cretaceous) beds. The barrier which 

 shut in this area of Trias on the southeast has been buried, but its 

 position was probably not far from the present southeast boundary 

 of the Triassic system in New Jersey. The older rocks are at or near 

 the surface at various points along this line. 



The considerable thickness of the sediments, together with the 

 decisive evidences of shallow-water or subaerial origin, such as ripple- 

 marks, sun-cracks, tracks of land animals, etc., which they bear, indi- 

 cate either that inclined deposition prevailed, or that subsidence of the 

 areas of sedimentation, either by bowing or faulting, accompanied the 

 deposition. For the adequate supply of the detrital material, it would 

 seem that the lands bordering the areas of deposition were raised, rela- 

 tively, as the troughs filled. These relations would account for the con- 

 tinued supply of coarse material which the series shows. Since the sedi- 

 ments were predominantly the products of the chemical decomposition 

 of the ancient rocks, rather than the product of mechanical disruption, 

 it is probable that the surrounding lands were not generally high. 



The prevalent redness of the formations, their structure, the presence 

 locally of limestone not known to be of marine origin, the existence 

 of coal-beds in some regions, and the character and paucity of the fossils, 

 indicate that the sediments accumulated subaerially, or in water which 

 was neither altogether fresh nor altogether salt for any long period 

 of time. The general conditions of accumulation may have been 

 similar to those under which the Catskill formation was deposited at 

 an earlier time. 



Former extent. — It is possible, and perhaps probable, that the 

 outlying areas of the Newark series from Virginia to South Carolina 

 were once connected with one another, and with the Virginia-New York 

 area, though such connection has never been demonstrated. It has 

 been suggested, though with little basis, that the Newark of the 

 Connecticut valley was once connected with that of Acadia. It has 

 been thought 1 that the New York- Virginia area was once connected 

 with the New England area, and that, as in the preceding case, the 

 separation was effected by erosion. This suggestion, however, does 

 not seem well founded. A formation of so great extent as such a 



1 Russell, N. Y. Acad. Sci., Ann., Vol. I, 1878; and Am. Nat., Vol. XIV, 1880 5 

 pp. 703-12; also Hobbs, Bull. G. S. A., Vol. XIII, pp. 139-148. 



