Geolofiy of Hudson CoiDiiy, New Jersey. 49 



I'ushes tluit border tlie upland, leave long lines of foot-prints 

 behind them. Mingled with these various markings are here 

 and there the fronds of ferns or cycads, and the twigs and cones 

 from the larger coniferous trees. When the next tide comes in, 

 all these records of physical changes and of animal and vegetable 

 life are covered with a layer of mud and sand, to be preserved 

 for indefinite ages. 



That such were the scenes along the base of the New Jersey 

 Highlands in Triassic times, every one can determine for 

 himself. 



On breaking open the stony layers, all the records just men- 

 tioned may be found as well-defined and legible, after millions 

 of years, as if impressed upon the soft sands but yesterday. In 

 these same beds are found in great abundance the remains of 

 the fishes that swam in the Triassic estuary ; these are lepido- 

 ganoids {CatojAerus, Iscliy liter us, etc.), covered with small dia- 

 mond-shaped scales, and have their nearest living representatives 

 in the " gar pikes" {Lejjidosteus) of our northern lakes, and the 

 Folypterus of the IS^ile. 



After long subsidence, during which thousands of feet of sedi- 

 ment accumulated in the Triassic estuary, a reverse movement 

 began and the bottom was upheaved, bringing the stratified 

 rocks, especially those of the central region, within the reach 

 of denuding agencies. The gradual folding of the crystalline 

 rocks beneath the Trias ended finally in the fracture of the rocks 

 in long lines parallel with the axis of upheaval. Through these 

 fissures molten rock from beneath was forced out, and found its 

 way into the stratified beds above, sometimes opening the layers 

 and forming intruded sheets of igneous rock, while at other 

 times the stratified beds were fractured, and the injected ma- 

 terial filled the fissures and formed true dikes. Examples of 

 each of these modes of occurrence, as already described, are to 

 be seen along the bank of the Hudson. In New Jersey, there 

 are four main lines of fracture through which the igneous rocks 

 escaped ; these are now indicated by the long curved mountains 

 of trap that diversify the scenery of the Triassic area. The most 

 easterly of these is the Palisade range ; this is bent into the form 

 of a crescent by having its extremities curved abruptly to the 

 westward. About ten miles westward of the Palisade range and 



