MINERAL INDUSTRIES. 
13 
so far as possible by the Survey. No geologic problem, perhaps, 
presents greater difficulties than the search for oil and gas. This 
is particularly true in Florida, where the surface is prevailingly 
level or but moderately hilly, and where good continuous surface 
exposures of the underlying formations are not numerous. How¬ 
ever, even in a flat country the underlying structure may in a meas¬ 
ure be determined through the aid of the occasional surface expos¬ 
ures of recognizable strata supplemented by well records. This 
problem of structure in Florida is receiving attention through co¬ 
operative study between the State Geological Survey and the Fed¬ 
eral Geological Survey and the results will be published as soon as 
they can be made available. From the reports of the Survey 
already issued much information may be obtained regarding the 
geologic structure of the State. 
PEAT. 
Peat is being produced in Beswick, Florida, by the Ranson 
Humus Company. This being the only plant in operation in the 
State, the production is not separately listed. The peat produced 
by this company is placed on the market in the form of prepared 
humus and peat litter. 
PHOSPHATE. 
Notwithstanding the interruption of normal export shipping 
conditions the production of phosphate rock in Florida during 1916 
shows a slight increase over that of the preceding year. The total 
shipment of phosphate rock in Florida during 1916, as reported by 
the producers, was 1,515,845 long tons. Of this amount 1,468,758 
tons were land pebble phosphate, the remainder being hard rock and 
soft phosphate. Of the total shipments only 200,472 tons were 
exported, or slightly less than during the preceding year. The 
domestic shipments, on the other hand, were in excess of those for 
the preceding year, both for hard rock and for land pebble. 
The value of the phosphate shipped from Florida during 1916 
was as follows: Land pebble, $3,847,410; hard rock, $295,755; 
total, $4,170,165. The value of the total shipments during the 
preceding year was $3,762,239. 
Summary of shipment of phosphate in Florida from 1913 to 
1916, inclusive: 
