32 
FLORIDA STATE GEOLOGICAL SURVEY. 
LOCAL DETAILS. 
SUWANNEE COUNTY. 
The southern and southeastern part of Suwannee County has pro¬ 
duced some phosphate, although no mines are operating in this county at 
present. A variable thickness of pale yellow sand occurs in the pits of 
this section. At the pits of plant No. 10 of Dutton Phosphate Company, 
two miles north of Hildreth, from two to twelve feet of this incoherent 
sand rests directly upon the phosphate bearing matrix. In one of the pits 
of this plant the phosphate matrix grades at the bottom into a yellow 
phosphatic clay overlying the limestone to a depth of 4 or 5 feet. In one 
of the pits at this plant are observed, as frequently seen elsewhere in the 
hard rock section, many large round elongate siliceous boulders inter- 
bedded in the phosphate matrix. The underlying formation here is the 
Vicksburg Limestone, which occurs as peaks and as “hog backs” of lime 
projecting into or even through the phosphate matrix. 
COLUMBIA COUNTY. 
The southern part of Columbia County, adjacent to Suwannee County, 
has produced considerable phosphate, although only one mine in this 
county was in operation at the close of 1912. 
At plant No. 2 of the Dutton Phosphate Company, now abandoned, 
about one-half mile west of Ichatucknee Springs, the following section 
was obtained: 
Pale incoherent sand. 10 to 20 feet 
Phosphate-bearing matrix . 20 to 25 feet 
Buff yellow phosphatic clays..• 5 to 6 feet 
Dark sandy phosphatic clays (exposed). 4 feet 
The incoherent sands in this pit, as at Dutton No. 10, rest directly 
upon the phosphate stratum, the top of which is exceedingly irregular. 
Clay lenses 6 to 12 inches thick are of frequent occurrence, especially near 
the top. The underlying limestone is reached in places. The buff yellow 
phosphatic clay observed in Dutton No. 10 is seen here also and is under¬ 
laid by 4 feet of dark, sandy' phosphatic clay. 
The following section was made in one of the pits of the Schilman 
& Bene phosphate plant, about two miles northwest of Ft. White: 
Pale yellow incoherent sand. 3 to 5 feet 
Fed clayey sands.. 5 to 10 feet 
Phosphate matrix . 15 to 25 feet 
Limestone at the bottom of the pit. 
