Hasandong Formation
| Hasandong Formation | |
|---|---|
| Stratigraphic range: Aptian-?earliest Albian ~ | |
| Type | Geological formation |
| Unit of | Shindong Group |
| Underlies | Jinju Formation |
| Overlies | Nakdong Formation |
| Thickness | 1,200 metres |
| Lithology | |
| Primary | Mudstone |
| Other | Shale, sandstone |
| Location | |
| Coordinates | 35°06′N 128°00′E / 35.1°N 128.0°E |
| Approximate paleocoordinates | 41°18′N 128°06′E / 41.3°N 128.1°E |
| Region | Gyeongsang Province |
| Country | South Korea |
| Type section | |
| Named for | Hasandong(Now called Hasan-ri), Daegu |
| Named by | Tateiwa, 1929 |
Hasandong Formation (South Korea) | |
The Hasandong Formation (Korean: 하산동층; Hanja: 霞山洞層; RR: Hasandong-cheung) is an Early Cretaceous geologic formation in South Korea. It has been dated to the Aptian to possibly the earliest Albian stage. Lee et al. (2018) estimated the maximum depositional age of the formation at 118.0 ± 2.6 Ma, and suggested that the overlying Jinju Formation likely had a maximum depositional age of 112.4 ± 1.3 Ma. Chae et al. (2026) examined the upper part of the Hasandong Formation on Yusu-ri, Jinju and on Jangguseom Island of Jungpyeong-ri, Hadong, and estimated the maximum depositional age of the upper part of the formation on each site at 116.9 ± 1.5 Ma and 113.4 ± 1.4 Ma respectively. Fossils including dinosaurs, turtles and pterosaurs are known from this formation.