404 MESOZOIC TIME. 



were formed in the course of the folding of the Appalachians, or 

 earlier. The formation may. be partly Jurassic, although no line of 

 division can be made out, either through transitions in the rocks or by 

 means of fossils. They lie unconformably on the folded crystalline 

 rocks, and thus show that they are subsequent to them in age. On the 

 map, page 144, the narrow areas are obliquely lined from the right to 

 the left. The principal of them are : — 



(1.) The Acadian area, situated along the western margin of the 

 peninsula of Nova Scotia, and about 1 50 miles long ; also in Prince 

 Edward's Island. 



(2.) The Connecticut Valley area, extending from New Haven on 

 Long Island Sound to Northern Massachusetts, having a length of 

 110 miles and an average width of twenty miles. 



(3.) The Palisade area, commencing along the west side of the Hud- 

 son River, in the southeast corner of New York, near Piermont, and 

 stretching southwestward through Pennsylvania, as far as Richmond, 

 Virginia, about 350 miles long. 



(4.) The North Carolina area, commencing near the Virginia line, 

 and extending through North Carolina, over the Deep River region, 

 120 miles long. 



There are also a few smaller areas parallel to these. 



The map of Pennsylvania, on p. 310, shows the position of the area 

 in that State, it being distinguished by the same oblique lining as on 

 the general map. It takes the same westward bend with the Appala- 

 chians of the State, retaining that parallelism with the mountains which 

 characterizes the areas elsewhere. 



Kinds of rocks. — The rock is in general a red sandstone; it passes 

 at times into a shale, and in others to a conglomerate. Occasionally 

 it includes beds of impure limestone. The sandstone is largely a 

 granytic sand-rock, it usually containing grains of feldspar and quartz 

 commingled, as if made of pulverized granyte or gneiss. There are 

 often sudden transitions from sandstone to coarse conglomerate ; and, 

 in many places, thin layers of large stones lie in the finer beds. 

 Many layers are obliquely laminated, in a coarse style, showing, like 

 the occurrence of the conglomerate, the action of powerful currents 

 in the deposition of their material ; while other portions are thinly 

 laminated and somewhat clayey, indicating regions of still waters or 

 eddies ; and still others are fine, even-grained, brownish-red sand-rock, 

 making an excellent building stone, and often called freestone — as the 

 rock at Portland on the Connecticut, and near Newark, New Jersey. 

 Near Richmond, Va., and along Deep River, in North Carolina, there 

 are valuable beds of bituminous coal. 



