48 Geology of Hudson County, Ne^o Jersey. 



morphosed shales, {S) while those forming Day's Point are light 

 yellowish feldspathic sandstones. 



The igneous rock of the Palisade range also shows that it must 

 have been confined by other rocks on the eastward, now removed, 

 or .else the molten rock would have poured out and formed a 

 table-land like those so common in New Mexico. At Haver- 

 gtraw, as already stated, the trap forms tlie top of the mountain 

 a thousand feet above the bed of the river. Such facts cannot 

 be explained except by supposing that the igneous rock was in- 

 closed in sedimentary beds at the time of its intrusion. All 

 this may seem a digression, but it is only when we assign the 

 few facts to be gleaned in the geology of Hudson County, to 

 their proper place in the long history of changes and revolutions 

 which our continent has undergone, that we can understand and 

 aiipreciate their full significance. 



During the deposition of the sand and mud now forming our 

 Triassic rock, the Highlands of northern New Jersey formed 

 part of the shore-line that bordered the estuary on the west. 

 Could we have stood beneath the ferns, cycads and spreading 

 coniferous trees which then shaded that picturesque coast, we 

 should have seen over all the region to the eastward — wliere are 

 now tlie fruitful farms of New Jersey interspersed with thriving 

 cities and villages — only rolling turbid Avaters ; their eastern 

 boundary far beyond the range of vision. When the tide was 

 out, a broad area of smooth shining mud bordered the shore, 

 closely similar to that now to be seen along the Bay of Fundy at 

 low tide. This plastic surface bordering the old Triassic estuary, 

 was the day-book on which the i-ecords of passing events were 

 inscribed. In fancy, we can see the wind ripjDling the waters 

 as they retreat from the shore, and forming the sand and mud 

 into low parallel ridges or '^rijaple marks." A cloud obscures 

 the sun, and soon great drops of rain patter on the strange vege- 

 tation around ; falling upon the soft mud, the rain-drops leave 

 little circular depressions, the nature of which indicates the di- 

 rection of the wind. In other places, many acres of the muddy 

 surface are croAvded with a net-work of intersecting fissures, 

 caused by the shrinking and cracking of the mud when it dries 

 in the sun. From the waters, strange uncouth monsters emerge, 

 and striding over the muddy shores towards the ferns and giant 



