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boundary is a circular wall of limestone, about perpendicular, and at a 
distance having quite the appearance of trap-rock. It lies in a position 
nearly horizontal, having but a very slight inclination to the west. In 
this neighborhood the limerock abounds in hornstone, generally black. 
When the western branch of this limestone reaches Great island in the ♦ 
drowned lands, its dip is to the northwest, and so continues to New- 
Jersey. The eastern preserves throughout, its usual positions. A small 
portion of this limestone is found in Minisink, on the west side of the 
drowned lands. This occurs at a point where the Walkill makes a con- 
siderable curve to the east. 
On Big island, in the drowned lands, some of the layers of this rock 
are oolitic, in several places near the village of Warwick; also half a 
mile north of New-Milford. 
H On Pochunck neck, about three miles from the New-Jersey line, 
some of the layers differ from any seen in the county. In some of the 
perpendicular cliffs, the edges of many layers are exposed, naked, one 
above another; some of these are of the usual character, others are ooli- 
tic; but the round granules are bluish white quartz; other layers still are 
slaty, approaching the calciferous slate; some of it has a ribbonlike ap- 
pearance; the lamina3 of light and dark-gray alternating in the layer. 
A locality, nearly similar, may be seen at Bellvale, on the land of Mr. 
Wilson. At this place some of the layers contain but little lime, and 
approximate closely in appearance the calciferous sand-rock of Prof. 
Eaton. 
The lime rocks of a later formation, which are found in the county 
oi Orange, remain to be noticed. In the town of Deerpark a stratum 
exists, which extends from the New-Jersey line to the county of Sulli- 
van. It reposes unconformably upon the mill-stone grit at the western 
base of the Shawangunk mountain; its position is almost vertical, the 
dip to the southeast; some layers of this stratum appear to be almost com- 
posed of shells, in others they are less numerous. Among the contents 
are two species of trilobite, the orthoceratite, terebratula, &c. Some lay- 
ers of this rock appear to be a slaty calciferous graywacke, and some 
are impure limestone, hard and compact, as well as slaty. 
These rocks, as a whole, form a narrow range of hills, or low moun- 
tains, sometimes sinking almost to the level of the Neversink valley, 
and at others rising to one-third or half the elevation of the Shawan- 
gunk. They are always narrow, and generally close to the base of the 
