Gaiman Formation
The Gaiman Formation (), in older literature also referred to as Patagonian Marine Formation (, "Patagoniense"), is a fossiliferous geologic formation of the Peninsula Valdés Basin in the eastern Chubut Province of northwestern Patagonia, eastern Argentina.

The thick formation overlies the Sarmiento Formation and is overlain by the Puerto Madryn Formation and comprises grey and white tuffaceous mudstones and sandstones, deposited in a shallow marine environment.

The Gaiman Formation has provided fossils of many extinct penguins, among which five species in the genus "Palaeospheniscus", as well as whales and dolphins, most notably "Aondelphis talen", "Prosqualodon australis", "Idiorophus patagonicus" and "Argyrocetus patagonicus", indeterminate seal and turtle fossils, shark and other fossils. The richness of the formation, and the other formations in the area, such as the underlying Sarmiento Formation, led to the establishment of the , with a Welsh name, reflecting the number of Welsh settlers in the region.
None
fossiliferous
UNK
Q736917
formation
Concept
None
Peninsula Valdés Basin
UNK
Q45007
Chubut Province
LOC
Q1507
Patagonia
LOC
Q414
Argentina
LOC
None
Sarmiento Formation
UNK
None
Puerto Madryn Formation
UNK
Q484924
tuff
Concept
Q6642424
mudstone
Concept
Q13085
sandstone
Concept
Q1994702
environment
UNK
Q9147
penguin
Concept
Q3889329
Palaeospheniscus
Concept
Q1865281
whale
Concept
Q7369
dolphin
Concept
None
Aondelphis talen
UNK
Q1006197
Prosqualodon australis
Concept
Q3021080
Idiorophus patagonicus
MISC
None
Argyrocetus patagonicus
UNK
Q7372
shark
Concept
Q9309
Welsh
Concept
Q188353
Welsh
Concept
Q85762494
Gaiman Formation
UNK
Q85762494
Gaiman Formation
UNK
country
located in the administrative territorial entity