of the Eastern States. 225 



shales and sandstones of this formation in New Jersey, and in 

 fact, save in the inclination of the beds, of all the Triassic 

 areas along the Atlantic slope. 



The dip of these strata, be it remembered, is eastward in 

 New England and northwestward in New Jersey • while in 

 Virginia and North Carolina, two similar belts of Trias exist, 

 with a like opposition in their dips. [See note A, page 253.] 



At many localities throughout the Trias of New Jersey, the 

 beds of sandstone and shale exhibit a thinning out of the strata 

 into wedge-shaped masses, known as current-bedding ; this 

 structure indicates the action of rapid and oft-changing cur- 

 rents of water during the deposition of the beds. The sur- 

 faces of the layers often exhibit peculiar markings, whicli aid 

 greatly in determining the physical conditions under which 

 these beds were accumulated. 



At many points towards the western border of this forma- 

 tion, as at Plainfield, Bound Brook, Pompton, and Boonton, 

 we have noticed ripple-marks, sun-cracks, rain-drop impres- 

 sions, and the foot-prints of animals. These same occurrences 

 have been recorded as likewise observed at Milford and Tum- 

 ble Station, in the extreme southwest portion of this area. 



When we attempt to gather these scattered pages of nature's 

 records, we are struck with the fact that the markings just 

 mentioned occur most abundantly along the western margin 

 of the sandstone formation. Foot-prints have never been dis- 

 covered eastward of the central portion. It is well known that 

 ripple-marks on rocks indicate that they were deposited in 

 shallow water, and that shrinkage-cracks, rain-drop impressions, 

 and the foot-prints of animals, are formed where broad areas 

 of muddy shore are exposed at low tide. From these consid- 

 erations, it may be concluded that the rocks bearing these 

 inscriptions were deposited in a body of water subject to 

 high tides. 



To arrive at comprehensive views as to the physical condi- 

 tion of the New Jersey and other Triassic areas, during the 



