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NEW RED SANDSTONE 
VII. NEW RED SANDSTONE. 
It is a singular fact, that this rock, whose position is above the Carboniferous series, 
should range along in close proximity to Upper Silurian rocks, almost touch the Old Red 
sandstone, and yet never be found reposing upon either. It occupies a small area only in 
New-York. It borders the west of the Hudson river for twenty miles, underlying all that 
remarkable and highly picturesque shore known as the Palisadoes. The sandstone sup¬ 
ports the pillars, the material of which seems to have been ejected through the rents in the 
sandstone beds. That this may have taken place is not at all improbable, inasmuch as 
the material of which the columns of greenstone are composed is interlaminated with the 
layers of sandstone in such a way that it can scarcely be questioned but that it Avas forced 
between them after consolidation, and while the greenstone was in a molten state. This 
statement is corroborated by the appearance of the sandstone. It is not only partially 
melted, but the iron, which formed a constituent part of it, is segregated into masses and 
thin veins in a crystalline state. Fig. 32 is an illustration of the relative position of the 
rocks near Slaughter’s landing. 
a. Horizontal beds of sandstone : the sandstone, when in contact with the greenstone above, is often white 
or gray, compact and hard, portions of which resemble hornstone or chert. 
b. Columnar greenstone, resting upon the sandstone. 
c. Injected beds of the same, and communicating with the columnar mass above. 
The New Red sandstone is undistinguishable lithologically from the Old Red or even the 
Medina sandstone : it is at base a conglomerate. The Potomac marble, as it is called, forms 
the base of this rock. This rare conglomerate rests on the Magnesian slate and Sparry 
