Earth:Sanbukdong Formation
| Sanbukdong Formation Stratigraphic range: early Albian 112.5 Ma | |
|---|---|
.jpg) Sanbukdong tracksite | |
| Type | Geological formation |
| Underlies | Alluvium |
| Overlies | Nansan Formation |
| Thickness | Over 300 m |
| Lithology | |
| Primary | Mudstone |
| Other | Sandstone |
| Location | |
| Coordinates | [ ⚑ ] : 35°58′N 126°39′E / 35.97°N 126.65°E |
| Region | North Jeolla Province |
| Country | South Korea |
| Type section | |
| Named for | Sanbukdong, Gunsan |
  Sanbukdong Formation (South Korea) | |
The Sanbukdong Formation (Korean: 산북동층; Hanja: 山北洞層; RR: Sanbukdong-cheung) is an Early Cretaceous geologic formation in South Korea. It has been dated to the Aptian-Albian stage.[1]
The lithology of the Sanbukdong Formation consists mostly of dark-grey mudstone, with occasional reddish mudstone and sandstone. Sedimentary structures, including ripple marks and cracks are often found. The age of the Sanbukdong Formation was initially suggested as Early Cretaceous based on plant fossil records[1], but Jeong et al. 2023 presented a more detailed age of this formation as 112.5±5.8 Ma based on detrital zircons, which spans from Aptian to lower Albian.[2]
A large dinosaur tracksite is known from the Formation, a total of 425 tracks including 14 trackways from 3 horizons, made by ornithopod and theropod trackmakers.[3] The tracksite was designated as Natural Monument of Korea in 2014, entitled <Tracksite of Dinosaurs and Pterosaurs in Sanbuk-dong, Gunsan>.
Fossil content
spinicaudatans and invertebrate traces are known from this formation.[1]
Icnhnofossils
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
|---|---|---|---|---|---|---|
| Caririchnium[3] | Sanbukdong tracksite | Trackways, divided into four groups based on size. The largest footprint is 51cm in length. | Entire morphology very similar to C. lotus. Ichnomorphological features suggested all tracks have been made by the same kind of trackmakers. | |||
| Theropoda[3] | Sanbukdong tracksite | Trackways, the largest footprint over 40 cm in length. | Entire morphology resembles Irenesauripus mclearni and I. glenrosensis. Attributable to Carcharodontosauridae trackmaker. | |||
| Pterosauria | Sanbukdong tracksite | Tracks | Not described formally | |||
| Koreanaornis[2] |
|
Unknown | Tracks | Continuous trackway consisted of 2 tracks attributed to K. ?dodsoni. Species identification of 3 isolated tracks not available. |
Plants
| Plants reported from the Sanbukdong Formation[1] | ||||||
|---|---|---|---|---|---|---|
| Genus | Species | Location | Stratigraphic position | Material | Notes | Images |
| Pseudofrenelopsis |
|
Leaves | ||||
| Cupressinocladus | C. sp. | Leaves | ||||
| Taxodiaceae | indeterminate | Cone structure | ||||
See also
- List of dinosaur-bearing rock formations
References
- ↑ 1.0 1.1 1.2 1.3 Choi, Pom-yong; Hwang, Jae Ha (2013). Geological report of the Gunsan, Buan, Banchukdo, Jangjado sheets (Scale 1:50,000). Korea Institute of Geoscience and Mineral Resources. pp. 1-76. http://library.kigam.re.kr/report/2013/%EA%B5%B0%EC%82%B0%EB%B6%80%EC%95%88%EB%B0%A9%EC%B6%95%EB%8F%84%EC%9E%A5%EC%9E%90%EB%8F%84%EB%8F%84%ED%8F%AD%EC%A7%80%EC%A7%88%EC%A1%B0%EC%82%AC%EB%B3%B4%EA%B3%A0%EC%84%9C.pdf.
- ↑ 2.0 2.1 Jeong, Dong-Gwon; Kim, Cheong-Bin; Cho, Kyu-Seong; Kim, Kyung Soo (28 February 2023). "Bird Tracks from the Cretaceous Sanbukdong Formation, Gunsan City, Jeollabuk-do, Korea". Journal of the Korean earth science society 44 (1): 36–46. doi:10.5467/JKESS.2023.44.1.36.
- ↑ 3.0 3.1 3.2 Lee, Yuong-Nam; Lee, Hang-Jae; Han, Sang-Young; Park, Euijun; Lee, Chan Hee (November 2018). "A new dinosaur tracksite from the Lower Cretaceous Sanbukdong Formation of Gunsan City, South Korea". Cretaceous Research 91: 208–216. doi:10.1016/j.cretres.2018.06.003.
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