56 
FLORIDA GEOLOGICAL SURVEY-I4TH ANNUAL REPORT 
THE GEOLOGIC DISTRIBUTION OE OIL AND GAS 
The oil first developed was chiefly from the Carboniferous and Devon¬ 
ian formations of Pennsylvania. Owing to this early development of 
oil in the United States from these older formations, the impression has 
become somewhat general that the late geologic formations are unfavor¬ 
able as a source of petroleum. However, oil and gas are not con¬ 
fined to the formations of any one geologic age, but have been obtained 
from formations varying in age from the Ordovician to the Tate Ceno- 
zoic. 
GEOLOGIC TIME TABLE 
For convenience of reference there is included here a geologic time 
table. In this table the time divisions are arranged in order, beginning 
with the most recent or Cenozoic. 
^ ( Recent. 
Quarternary. 1 . 
( Pleistocene. 
Pliocene. 
Miocene. 
Oligocene. 
Eocene. 
{ Cretaceous. 
Jurassic. 
Triassic. 
Cenozoic ^ 
Tertiary. 
Paleozoic 
Permian. 
Pennsylvanian. 
Mississippian. 
Devonian. 
Silurian. 
Ordovician. 
Cambrian. 
Algonkian. 
Archean. 
With the exception of the Archean, Algonkian and Cambrian, prob¬ 
ably all the time divisions given in this list contain petroleum-bearing 
formations. Notably large producing formations are found in the Ter¬ 
tiary, Cretaceous, Pennsylvanian, Devonian and Ordovician divisions. 
The oil production of Touisiana is from the Cretaceous and Tertiary 
formations. In Texas, .oil is obtained from the Tertiary, Cretaceous, 
