Alajuela Formation
The Alajuela Formation, originally Alhajuela Formation (Tau), is a Late Miocene (Tortonian, Early Hemphillian or Latest Clarendonian in the NALMA classification) geologic formation in the Panama Canal Zone of central Panama.

The formation overlies the Caimito Formation and comprises sandstones, limestones and conglomerates deposited in a tidal-dominated estuarine to shallow marine environment.

The formation crops out in a small area along the southern and western shores of Lake Alajuela, of which it derives its name, and preserves a rich fossil faunal assemblage of mammals, fish (among which fossil teeth of megalodon), invertebrates and flora. The fauna is of paleontological significance as an insight into the ecosystem of Central America preceding the Great American Biotic Interchange (GABI).
Q76267
Late Miocene
TIME
Q499299
Tortonian
TIME
Q5712685
Early Hemphillian
LOC
Q5126898
Latest Clarendonian
LOC
Q1920925
NALMA classification
Concept
Q736917
geologic formation
Concept
Q498979
Panama Canal Zone
LOC
Q804
Panama
LOC
Q17986199
Caimito Formation
LOC
Q13085
sandstone
Concept
Q23757
limestone
Concept
Q191704
conglomerates
Concept
Q47053
estuarine
Concept
Q1994702
environment
UNK
Q1416924
Lake Alajuela
LOC
Q7377
mammal
Concept
Q152
fish
Concept
Q163873
megalodon
Concept
Q43806
invertebrate
Concept
Q131449
flora
Concept
Q278170
Great American Biotic Interchange
UNK
Q17985477
Alajuela Formation
LOC
instance of
country
underlies