S8 JOURNAL OF THE 



In the irregular water- worn depressions on top of this limestone 

 rock, in the vicinity of Six Mile Creek, and underlying the super- 

 ficial sands, occur frequently beds of post pliocene shells, unmixed 

 with the sand or clay, and generally unbroken. These in a few 

 places are found near water level, but more generally they are to 

 be found at an elevation of two to seven feet above tide water. 

 Above the railroad bridge the creek narrows to a small brooks 

 crooked, with a bottom of shell rock, and this rock extends up into 

 the high cliffs, ten to fifteen feet. On top of it there can be found 

 detached beds of post pliocene remains. 



On Alefla river, east side of Hillsboro Bay, and a few miles dis- 

 tant, under the bridge, the bottom and banks, to a height of three to 

 four feet are of limestone rock, which in the bed of the stream shelves 

 out across the river and produces a series of rapids. The rock is a 

 rough coralline and conglomerate-coprolitic limestone, containing 

 many fragments of bone and small sharks teeth, much whitish, 

 yellow and dark chalcedony, large blocks of silicified coral and 

 oyster shell. There is also much coprolitic gravel with sharks teeth 

 and Dones gathered along the shore in heaps, drifty. Three-fourths 

 of a mile below the bridge the rock at water contains a layer six to 

 eight inches thick of silicified shell rock, (coquina), and under this 

 is a soft light colored sandy marl, half compacted with black cop- 

 rolitic grains. 



Near Bloomingdale, half mile south, is a lime-sink, 45 feet deep 

 by 250 feet wide. A section down through the sides of this shows, 

 going downward, for first J 5 to 20 feet from top, brown and gray 

 sand ; then 10 feet of brown sand with marly lumps, and calcareous 

 gravel with patches of marly clay; then marl, light colored, sandy, 

 with black phosphatic gravel at 30 to 35 feet; below this comes a 

 whitish limestone in irregular masses, more or less silicified and con- 

 verted to a calcareous sand rock. 



At Bradentown, on Manatee river, five miles from its mouth, the 

 bluff, fifteen feet high, is sandy ; but five miles further up the river 

 at Rocky Bluff, on north side, it consists of a yellowish white, rough, 

 weathering, siliceous limestone, extending five to six feet above tide 

 level, and visible one to two feet below water surface. The rock, 

 here, is shelving, cavernous; one-fourth mile down the river the 

 rock is visible at low tide, shelly and soft. 



Near Col. Forester's orange farm, four miles up the arm of a creek, 

 from Bradentown, the rock is visible in banks of creek for half 

 mile two to three feet above high tide water, and exists also in bed 



