| Chilgog Formation | |
| Type: | Geological formation |
| Age: | Albian |
| Period: | Albian |
| Prilithology: | Sandstone, mudstone, conglomerate |
| Otherlithology: | Tuff |
| Region: | Gyeongsangbuk-do |
| Coordinates: | 36°N 128.5°W |
| Paleocoordinates: | 40.9°N 128.3°W |
| Unitof: | Hayang Group |
| Underlies: | Silla Conglomerate |
| Overlies: | Jinju Formation |
| Thickness: | Up to 650m (2,130feet) 295m (968feet) in the western Daegu area |
| Extent: | Gyeongsang Basin |
The Chilgog Formation, also known as the Chilgok Formation, is an Early Cretaceous geologic formation in South Korea.[1] Formerly dated to the Berriasian to Hauterivian, later dating has established an Albian age.[2] Dinosaur remains, possibly of sauropods,[3] are among the fossils that have been recovered from the formation, although none have yet been referred to a specific genus.[4]
The formation predominantly consists of sandstone, mudstone and conglomerate, with subordinate tuff and other volcanics.[5] It overlies the Jinju Formation and underlies the Silla Conglomerate, which underlies the Haman Formation, respectively.