The Soncco Formation is a Late Eocene to Early Oligocene geologic formation in southern Peru.
The base of the formation at the contact with the K'ayra Formation is dated using fission track analysis at 43 Ma and the top, the contact with the Punacancha Formation, at 30 Ma.
[3] The formation was first dated to the Cretaceous, and fossil ornithopod tracks had been reported.
[4] Over 9,000 fossil tracks are said to be found within this formation.
[citation needed] As the formation has been dated to the Paleogene, the tracks could not be attributed to dinosaurs.