MESOZOIC TIME — TRIASSIC AND JURASSIC. 799 



In Connecticut, the sandstone beds almost invariably dip eastward. 

 In Virginia, in the Richmond area, which is one of the easternm.ost, the beds 

 have a synclinal structure, the rocks on the east side dipping northwestward, 

 and those on the west side, southeastward (Fontaine). In the eastern Deep 

 River area of North Carolina the dip averages 20° southeastward, but varies 

 from 10° to 35° (Fontaine). 



Notwithstanding the diversity between the orographic features of the 

 more western and the eastern belts, the intimate relation to the Appalachian 

 system as regards method of upturning of the former as well as of the latter 

 cannot be questioned. The opposition of direction in dip is connected with 

 opposition in all other structural features in the two ranges of belts, and 

 eminently so in the topography. 



The opposition in dip betw^een the Connecticut valley and the Palisade 

 area has been explained by supposiug that the sandstone was made in waters 

 that spread over the intervening region, and that an actual anticline was 

 produced by an uplift. But only marine waters could have covered the wide 

 region after great subsidences ; and to this idea, all the facts as to the fresh- 

 water origin of the beds by fluvial, lacustrine, or estuary agency are opposed. 

 Moreover, the Connecticut valley area is wholly in latitudes more northern 

 than the Palisade. 



This reversed condition, so marked in the results over the two areas, 

 simply implies reverse action in the forces concerned. In the Palisade region, 

 accordingly, the lateral pressure was from the westward; thus came the 

 reversed dip and reversed fault-planes and faulting. On this view of the 

 action along the two belts, — that is, the lateral thrust from the eastward for 

 the eastern, and from the westward for the western, — the pressure was such as 

 would tend to make, or actually did make, a geanticline between two extended 

 lines, an eastern and a western. But upturnings of beds took place only 

 where there had been geosynclines of deposition, that is, in the Triassic areas. 



The effective upturning force acted alihe from opposite directions, the 

 eastern, or oceanward, and the western, or landward ; while in the Appalach- 

 ians its action was from the eastward chiefly ; but, still, like the Appalachian 

 Range as a whole, each of the several areas is inequilateral in orogenic struc- 

 ture. The Connecticut valley area tapers out, both as to width and depth of 

 deposits, at New Haven Bay on the Sound. There is no trace of the trough 

 over Long Island. It is possible that in the direction of this eastern Triassic 

 line a sandstone area existed over the shallow-water border of the Atlantic, 

 south of Long Island and east of New Jersey ; but no proof of this has been 

 observed. In the Richmond area of eastern Virginia, however, and in the 

 Deep River area of North Carolina, as the dip of the beds of each proves, the 

 true continuation is found, for these areas have the same position relatively 

 to the western areas of those states, as the Connecticut valley area has to 

 the Palisade area. The map on page 412 illustrates the fact, not only 

 that these areas mark out the position of the eastern side of the series of 

 Triassic belts, but also that it is parallel to its axial line. 



