36 Geology of Hudson County, Neto Jersey. 



Hill and Little Snake Hill, rising as islands in the salt marsh. 

 1'he former of these is 175 feet high, and is about one and a half 

 miles in circumference ; the second, situated about 80 rods to 

 the eastward, is very much smaller, with an elevation of 78 feet. 

 These are chimney-like protrusions of trap that have been forced 

 out between the laj'crs of sandstone, causing some disturbance, 

 and are without doubt connected some distance below the sur- 

 face with the main trap-sheet forming Bergen Hill. The trap- 

 rock protruding at Snake Hill is of the same nature as that 

 forming Bei'gen Hill, Avhich will be described further on. As 

 already noticed, the sedimentary beds, when they come in con- 

 tact with the igneous rock forming Snake Hill, are very much 

 shattered, and altered in texture ; the trap seems to have fol- 

 lowed in a general way the bedding of the sedimentary strata, 

 but has increased the dip of the sandstone on the northwest side 

 to 30° or 35°. 



As previously mentioned, the trap-ridge forming the elevated 

 region of Bergen Hill, is a portion of the Palisade range ; this 

 ridge is highi'st at its northern end, and descends quite uni- 

 formly towards the south. At Haverstraw, the loftiest summit, 

 called the High 'J'orn, is 1015 feet above the Hudson ; opposite 

 Hastings the elevation is 489 feet, the highest point of the ridge 

 in New Jersey ; at Gnttenberg, near the northern boundary of 

 Hudson County, the elevation is 260 feet ; thence it de- 

 creases in liight southward, until at Bergen Point the trap 

 has been cut through by the Kill Von KuU. In the north- 

 ern portion of the county the trap is fully a mile and a half 

 wide, and narrows quite regularly when followed southward. 



At a few localities along the eastern shore of Newark Bay, 

 the trap-rock may be observed coming up from beneath the 

 water, with its usual dip of ten to fifteen degrees northwest ; 

 it is only along the shore, where the superficial material has 

 been removed, that the trap-rock beneath can be seen ; over 

 nearly the whole of Bergen Neck and Bergen Point it is concealed 

 by drift and sand-dnnes. On the eastern side of Bergen Neck, 

 near Greenville, the trap protrudes in a dome-shaped mass, 

 showing a roche-moutonnee surface, and several bold rounded 

 knobs, also exhibiting glacial action, protrude above the sur- 

 rounding drift along the Morris Canal, where it passes through 

 the hill. 



