ANNUAL REPORT—ROAD MATERIALS. 
47 
ROCKS OF FLORIDA CLASSIFIED ACCORDING TO ORIGIN. 
Rocks Of— 
Mechanical origin 
Organic origin 
T Sandstones, 
<; Shales, 
[ Clays. 
{ Shell limestone, 
Infusorial earth, 
Muck, peat, lignite. 
Chemieal origin 
Formed by pre¬ 
cipitation and 
chemical segre¬ 
gation. 
Formed by re¬ 
placement. 
f Bog iron ore, 
| Oolitic limestone, 
<| Land pebble pilos¬ 
is phate (?) 
' Flint or chert, 
Crystallized 1 i m «- 
J stone, 
Hard rock phosphate 
(in part). 
ROCKS OF FLORIDA CLASSIFIED ACCORDING TO CHEMICAL 
COMPOSITION. 
Disregarding mode of origin and placing the rock* 
according to chemical composition, the classification may 
be arranged as follows: 
r Flint and chert, 
Siliceous rocks. S Sandstone, 
k Infusorial earth. 
Argillaceous rock 
\ Clay, 
( Shale. 
Calcareous rock 
' Shell limestone, 
Crystallized limestone, 
Oolitic limestone, 
Marl. 
Carbo-Hydrates... 
Ferruginous rocks 
Phosphatic rocks.. 
Muck, peat, lignite. 
Bog iron ore. 
Hard rock phosphate, 
Pebble phosphate. 
S? 
