SECOND ANNUAL REPORT-SOUTHERN EEORIDA. 
205 
Record of wells of Florida East Coast Railway, Marathon. 
Feet. 
Reef rock ... 0-105 
Hard to soft white limestone, with much white marl.105-148 
Soft white limestone with shell casts .148-150 
Medium hard white limestone, shell casts and shell fragments.150-155 
Soft white limestone with quartz grains, proportion of quartz increasing 
with depth, shell fragments and casts.155-176 
Medium fine white quartz-sand containing numerous irregular nodules, 
with yellowish marly sand at 210 to 215 feet.176-230 
Quartz sand in a varying proportion of limy mud, sand grains, colorless 
mud, yellowish to dark green; streaks and beds of friable sand¬ 
stone containing shell casts; bed of oyster shells at 240 feet.230-300 
Quartz sands or beds of soft friable sandstone containing shell casts; 
streaks of dark green limy clay, 306-310 ft.; beds of shells, few 
determinable fossils, probably Miocene, 378-390 .300-400 
Quartz sands as below 230 feet; beds of soft friable sandstone with shell 
casts; gravel bed with much worn pebbles up to 40 mm. long; 
tough green limy clay, at 407 to 410 feet.400-435 
Quartz sands with little sandstone, tough dark clay in occasional streaks. .435-700 
While the many samples of drillings from this well show the litho¬ 
logy of the formations penetrated, they give much less satisfactory 
evidence as to geologic age. The sands below 176 feet yielded but a 
small variety of determinable fossils. An occasional claw or carapace 
of a small crab or a few barnacle plates were the only organic remains 
noted in going through many feet of sand. The friable sandstones 
contained many casts, internal and external of pelecypod shells, the 
external casts being of sandstone, the internal of more clayey material. 
These casts while numerous, were not sharp enough to be of diagnostic 
value. 
The shell beds yielded a small variety of species. T. Wayland 
Vaughan identified five species including pectens and an oyster which 
were probably Miocene from collections between 375 and 420 feet. 
Thus the Key Vaca section, while it shows limestone, Pleistocene, 
and sands probably Pliocene, gives no data for separating Pliocene from 
Miocene. The coarseness of the sands, their barrenness and the char¬ 
acter of the few determinable fossils between 176 and 400 feet indicate 
shoal water and strong currents. No break in deposition is deter¬ 
minable. 
Key West;—Samples collected at 25-foot intervals from the deep 
well at Key West were examined by E. O. Hovey. The following- 
generalized log is from his detailed description of the samples down 
to 2000 feet. 
