SECTION OF NIAGARA FALLS. 



Plate 7. 



The rocks and formations at the Niagara Falls 

 and River, are twelve in number, and are mostly 

 described by Mr. James Hall, one of the Geologists 

 of the State of New York. 



1st Red Marl. — (See plate 7, Jig. 1.) This is 

 the lowest rock, the bottom of which lies below 

 the level of Lake Ontario and is of a somewhat 

 destructable kind.* 



2nd Sandstone. — (See plate 7, Jig. 2.) This 

 Sandstone is said to be twenty-five feet thick, and 

 is of the hardest kind, and not easily worn away 

 by water. I suppose this Sandstone, which forms 

 an irregular bar across the river,) by its hardness 

 and its not being acted upon easily by the running 

 water, its projection above the level of the marl 

 which it overlies, and which is easily removed by 

 the fierce stream, and by its crossing the river,) to 

 cause, what is called the whirlpool ; there is an 



* In the Geological reports of the State of New York, all soft crumbling 

 Rocks seem to be called Marl, and many of the Sandstones, Grits. 



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