78 
DEPOSITS OF PHOSPHATE OF LIME, 
[BULL 46. 
Table of analyses of amorphous nodular phosphates of Alabama — Continued. 
[II. Southern belt. (Bulletin No. 5 of the department of agriculture of Alabama.)] 
Insoluble 
matter. 
Phosphoric 
acid. 
Bone phos- 
phate. 
Nodules from near Livingstone 
Nodules from near Livingstone 
Shell casts and nodules from near Coatopa 
Shell casts from Moscow 
8.48 
15.02 
9.38 
25.52 
1.10 I 
14.56 
1.55 
2.40 
1.39 
31.78 
3.38 
AMORPHOUS NODULAR PHOSPHATES OF MARTHA'S VINEYARD. 
The phosphates of Martha's Vineyard occur as black or dark-gray 
nodules, varying from one-fourth of an inch to four inches in diameter, 
in two beds of Greensand. The beds are of Tertiary age and are well 
seen in the cliffs at Gay Head. They are each 18 to 24 inches thick 
and dip at an almost vertical angle. They are associated with beds of 
lignite, clay, and sand. The nodules are mixed with numerous bones 
of cetaceans, crustacean remains, and other fossils. The more southerly 
of the two beds contains 5 to 15 per cent, of nodules and bones, while 
the bed to the north contains in some places almost no nodules, and 
in others as much as 25 r>er cent, of them. The nodules have a water- 
worn appearance and have been much bored by marine mollusks. 
They give off a smell of decayed organic matter when two fragments 
are rubbed together, and have a hardness of about 3. 
This deposit has not yet been put to any practical use. The nodules 
are probably too scattered in the bed and too expensive to mine to al- 
low them to be of any commercial value. 1 
AMORPHOUS NODULAR PHOSPHATES OF FLORIDA. 
Phosphate deposits have been found in various places in Florida, 
but as far as is yet known they are either of too small extent or of too 
poor quality to pay for mining. The only deposit which covers more 
than a few acres is found in Alachua County, near the central part of 
the State. The phosphate found here belongs to the subdivision of 
phosphatic conglomerates. The rock consists of small pebbles, from 
the size of a mustard seed to that of a pea, closely packed in a matrix 
of indurated calcareous marl. The pebbles are very compact, have a 
small conchoidal fracture and sometimes an enamel-like luster. They 
are creamy white to chestnut brown in color and are associated with 
1 It seeins to me certain that these beds containing nodules were deposited in the 
delta of a large river and that the nodules, together with the greater pait of the fos- 
sils with which they are intermingled, were derived from pre-existing strata in essen- 
tially the same manner as those which occur in the estuaries of the rivers near 
Charleston, S. C. 
For a further description of these deposits see a report on the island of Martha's 
Vineyard, nowin press, to appear in the Seventh Annual Report of the U. S. Geologi- 
cal Survey. -N. S. S. 
(552) 
