186 Account of the Geology, Mineralogy, Scenery, &. 
thern side to Kedidika Hook ; it there takes a northwest 
direction parallel with the river for four miles, rising abrupt- 
ly from the water to a great height ; its ledges in many 
places precipitous are composed of the materials observed 
in the Palisado rock, with the addition in some parts of 
the summit of a little sulphur rendering it friable. The 
dred feet perpendicular height borders the summit. Sand- 
stone in place is found on the side and at the base of the moun- 
tain. Piles of dark angular blocks of greenstone in many pla- 
ces occupy the sides of the mountain to the exclusion of ve- 
getation. Puddingstone, containing smooth round pebbles 
is frequently observed. From Haverstraw the greenstone 
mountain ranges in a western course and sweeps with a di- 
minished height to the vicinity of the Highlands, presenting to 
n is 
the eye a profile of wild and irregular eminences. Iro 
tion of Rockland county was once contemplated. Rich 
copper ore has been found not far from High Tower, but 
the traces of it are lost. On the southern side of the 
mountain running west from Haverstraw, the descent is in- 
general gradual; much of the surface is cleared and culti- 
vated and of a medium soil, well watered by numetous 
springs ; large rolled masses of granite and gneiss rest OM 
the mountain side, probably conveyed to this secondary re 
gion from the Hizhlands by some convulsion of nature.— 
Pectanites and other marine petrifactions have been found 
on this ridge at considerable elevations ; fine grained trap 
is met with at the base. ah 
_ Westward of the Kedidica Hook range, and half a mile 
from the Hudson is situated a mountain lake four miles 16 
circumference, called Rockland lake ;—its surface is 
feet above the bed of the river from which it is separated — 
