210 
FLORIDA state geological survey. 
glades. It is underlain, so far as can be told from the records of the 
few wells that have penetrated it, by marl and sand. 
Seaward it may grade into coarser and less solid rock overlain 
by the deposits of coquina forming the backbone of some of the barrier 
beaches of the east coast. The limestone has not been seen in contact 
with the coquina and the exact relations remain to be proved. To the 
south the limestone may underlie or grade into the Miami oolite, 
but the two have not been seen in contact. 
Lithologic Characteristics:—At the type locality in T. 45, R. 41, 
twelve miles west of Lantana, the rock is a white to yellowish limestone, 
containing a variable proportion of fine to medium quartz sand. The 
lime cement is not coarsely crystalline, nor does the rock contain, like 
•other limestones of southern Florida, many patches and streaks of 
coarsely crystalline calcite, replacing amorphous material or filling 
cavities left by the solutions of shell fragments. Its hardness varies 
greatly; in some places it is compact, dense and rings under the ham¬ 
mer ; in others, the proportion of sand is so great that the rock becomes 
a friable calcareous sandstone. 
Thickness:—Owing to the low elevation of the belt of country 
where the outcrops are found and the horizontal position of the lime¬ 
stone, the only evidence available to determine the thickness is that of 
well records. The testimony of these is contradictory, as is to be 
expected from the fact that most of them are given from memory. 
Such evidence as can be had, however, indicates that the limestone may 
be from five to fifty feet thick. 
Physiographic Expression:—From the low relief of the pinelands 
and the monotonous flatness of the ground, it can not be said of the 
Palm Beach limestone that it contributes to the physiography of the 
country. It helps, however, to define the eastern boundary of the 
Everglades for possibly thirty miles. 
Paleontologic Characteristics:—The Palm Beach limestone is, as 
a whole, abundantly fossiliferous. The fossils comprise gastropod and 
pelecypod shells, all of marine type and probably of living species. 
Corals, as is to be expected from the sandy character of the limestone; 
are rare or absent. In places, the rock is full of shells of Chione can - 
cellata, nicely bedded, with both valves closed, indicating that the 
shells had not been disturbed since the mollusks died. The limestone 
thus has the facies of a shallow water deposit formed in bays or 
lagoons with bottoms of sand or sandy marl. 
Areal Distribution:—The northernmost exposure of the Miami 
oolite that the writer saw was in T. 47, R. 42, five miles south and seven 
miles west of Delray. The southernmost exposure seen of non-oolitic 
limestone is over five miles to the north. There are outcrops between 
