SECOND ANNUAL REPORT—MINERAE INDUSTRIES. 
239 
occur. The matrix of the phosphates of this formation is either sand 
or lime. 
Calcareous and phosphatic sandstone inclusions are found in and 
beneath the red sands and sandy clays of Leon, Jefferson and Gadsden 
Counties. The sandstone fragments in these deposits probably repre¬ 
sent inclusions from an older formation washed in from the near by 
land surface during the deposition of the sands and clays. This 
calcareous or phosphatic sandstone probably representing the Alum 
Bluff sands may be seen apparently in position in the Georgia, Florida 
and Alabama Railroad cut about two miles northwest of Tallahassee, 
and at the ‘‘basin’’ or sink at Lake Miccosukee. Very similar phos¬ 
phatic material occurring in “Nigger Sink” near Alachua, described by 
Johnson, is regarded by Dali as representing the Hawthorne beds at 
that locality. Sandstone of similar character occurs at Alachua Sink 
near Gainesville. 
In Wakulla County low grade phosphates have been reported by 
several observers. In 1886, previous to the discovery of either the 
Peace River or the hard rock phosphates Dr. John Kost, then acting 
as State Geologist, reported the occurrence of low grade phosphate in 
Wakulla County near Sopchoppy and along the Ocklocknee River. 
The matrix at this locality is likewise a sandstone, and is probably also 
of the Alum Bluff formation. 
Phosphate in a gray coarse sandstone matrix occurs in Hamilton 
County, having been mined to a limited extent near the Allapaha River, 
west of Jasper. River pebble occurs in this county north of Jennings, 
near the Georgia-Florida state line. 
Certain low grade phosphates near Hawthorne are reported to 
have been the first of the Florida phosphates to be used as a fertilizer. 
Samples of a limestone at this locality used as a building rock were 
found to contain in some cases as much as 16.07 per cent of phosphoric 
acid 1 (equivalent to 35.09 per cent of tricalcium phosphate). During 
1883 or 1884 pebble phosphates occurring about one mile west of this 
quarry were ground to form a fertilizer by Dr. C. A. Simmons. 
Phosphatic limestone occurs at the Devil’s Millhopper near Gaines¬ 
ville. The exposure at this locality has usually been referred to the 
Hawthorne formation. 
In a deep sink about three miles southeast of Brooker in Bradford 
County thirty-nine feet of matrix containing varying amounts of peb¬ 
ble phosphate lie beneath thirty-seven feet of shell marl, and covered 
slope. The detailed section at this sink is as follows: 
1 Smith. Cotton Production Report, 10th Census of the United States, 1880, 
pt. it, p. 194, 1884. Hawes. Proc. U. S. National Museum for 1882, pp. 46-48, 
1883. 
