PETROLEUM POSSIBILITIES OE FLORIDA 
121 
marls are seen only where cut into in the construction of drainage 
ditches. Excavations in which this marl is well exposed will be found 
west of the town of Vero and northwest of Ft. Pierce and at Fellsmere. 
In the northern part of the county the Eocene limestone may lie within 
about 370 feet of the surface. This seems probable from the fact that 
at Fellsmere artesian water in quantity such as is usually obtained from 
the Eocene or older formations in Florida was secured at this depth. 
At Ft. Pierce, about 25 miles further south, the Eocene limestone has 
been identified from samples at a depth of 670 feet from the surface. 
If these records are correct, they indicate a south dip in the Eocene lime¬ 
stone, amounting to about 300 feet in 25 miles. 
Following is the log of a well at Ft. Pierce, taken from the Fifth 
Annual Report of this Survey, page 247: 
Depth in feet. 
Yellow sand .... 0-55 
Shell and sand ....—. 55-75 
Shell and gravel .,..... 75- 85 
Shell, sand and clay.... 85-120 
Blue clay and sand......... 120-135 
Soft, blue clay and very fine sand.. 135-145 
Blue clay and sand....... 145-165 
Blue clay ...’. 165-190 
Tough, dry, blue clay. . .. 190-200 
Soft, sandy, blue clay.... 200-250 
Hard, sandy, blue clay...:. 250-300 
Smooth, blue clay, no sand.... 300-400 
Blue clay, very tough and sticky.1. 400-460 
Yellow clay, with black streaks in it...... 460-500 
Yellow clay, with a few pebbles.fill.:.. 500-520 
Blue clay, tough and sticky....H.... 520-545 
Very hard, yellow clay.. 545-555 
Blue clay, very sticky..i..:...... 555-585 
Yellow clay in hard and soft layers...... 585-600 
Yellow clay, very dry...... 600-647 
Shell and soft rock...fjjjjjPI. 647-656 
Tough, white clay... 656-662 
Hard, white rock ...... 662-676 
Soft rock, small flow....... 676-685 
Soft limestone rock, flow increasing very slowly with depth.... 685-807 
Hard rock ....... 807-814 
SANTA ROSA COUNTY 
Santa Rosa County, in west Florida, extends from the Alabama state 
line to the Gulf of Mexico. The surface deposits, as far as observed 
in this county, consist wholly of non-fossiliferous sands and more or 
less sandy clays. It is difficult to determine the age of such deposits. 
