VIEW SHOWING EXPOSURE OF THE ALUM BLUFF 
FORMATION. 
Fig. 13!—Alum Bluff on the Apalachicola River. Made from a photograph 
taken by Dr. E. A. Smith, Oct. 29, 1890. This bluff, at the base of which is found 
the type exposure of the Alum Bluff formation, is about 166 feet high. 
The Alum Bluff formation is extensive in Florida and is exposed 
at many localities from the Apalachicola River to Sarasota Bay. 
This formation, which is more or less phosphatic throughout, is of 
special interest in connection with the phosphate deposits since from 
it directly or indirectly has been derived the workable phosphate beds 
of Florida. 
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