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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 nil 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 was 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 wliicli resemble hornstone or chert. 



b. Columnar greenstone, resting upon the sandstone. 



c. Injected beds of the same, and communicating witli tlie columnar mass above. 



The New Red sandstone is undistinguishablu lithologically from the Old Red or even the 

 Medina sandstone : it is at base a conglomerate. The Potomac uiarlde, as it is called, forms 

 the base of lliis rock. This rare conglomerate rests on the Magnesian slate and Sparry 



