REVIEW OF THE GEOLOGY OF FLORIDA 
127 
212-240 feet, dark colored very sandy marl or calcareous sands, some broken 
shells. 
240-245 feet, olive green very sandy and calcareous clays, or clayey sands. 
245-276 feet, very sandy dark colored marl with shell fragments. 
276-300 feet, calcareous and very sandy clay or clayey sand. 
300-380 feet, dark colored sand, broken rock and shell fragments. 
380-403 feet, very sandy dark colored marl, sand grains small. 
403-458 feet, light colored sandy marls, some shell fragments. 
458-468 feet, dark clay and broken shells. 
468-500 feet, drab colored clay. 
510 feet, white limestone rock with fragments of echinoderm spines. 
608 feet, chiefly sand. 
615 feet, white limestone with many fossils. 
775 feet, limestone powdered fine by the drill. 
The following is a record of the well of the Florida East Coast 
Railway Company drilled at Marathon on the Florida Keys in 
1918. The well is cased as follows: 10-inch casing resting at 589 
feet; 8-inch casing resting at 605 feet; 6-inch casing extended to 
1,128 feet. 
Depth of sample from surface. 
At the surface, coraline limestone, very hard. 
35-179 feet. Represented by nineteen samples. All hard limestone, mostly 
finely powdered by the drill. 
108-274 feet. Two samples. Very fine white sand, containing well rounded 
small grains of the' mineral Ilmenite. 
305-409 feet. Four samples. Sand, medium coarse^ slightly greenish in color, 
includes small amounts of clay. 
412-425 feet. Very coarse sand, including some phosphate pebble. Two 
samples. 
427-428 feet. Two samples. Coarse siliceous pebbles, including much peb¬ 
ble phosphate. 
429-471 feet. Four samples. Medium coarse sand, greenish in color. 
427-480 feet. Two samples. Coarse sand including clay balls. 
571-584 feet. Medium coarse sand, mostly greenish in color, contains some 
clay fragments and some phosphate pebble. Seven samples. 
584-589 feet. Coarse sand with phosphate pebble. Three samples. 
593 feet. Porous white limestone, fossils preserved as casts. 
598 feet. Coarse sand including phosphate pebble. The material of this 
sample probably fell from above as the 10 inch casing had 
not yet been set. 
601-1790 feet. Numerous samples. Limestones. 
