Guanling Formation
The Guanling Formation is a Middle Triassic (Anisian or Pelsonian in the regional chronostratigraphy) geologic formation in southwestern China.
| Guanling Formation Stratigraphic range: early-mid Anisian (Pelsonian) ~247–245 Ma | |
|---|---|
| Type | Geological formation |
| Underlies | Yangliujing Formation |
| Overlies | Jialingjiang Formation |
| Lithology | |
| Primary | Mudstone, limestone |
| Other | Dolostone |
| Location | |
| Coordinates | 25.5°N 104.9°E |
| Approximate paleocoordinates | 11.7°N 94.2°E |
| Region | Guizhou & Yunnan Provinces |
| Country |  China |
| Extent | Yunnan–Guizhou Plateau |
  Guanling Formation (China)  Guanling Formation (Guizhou) | |
Description
The formation encompasses two members. The first member is primarily calcareous mudstone and dolomite, indicative of a coastal environment. The second member is a thicker marine sequence of dark micritic limestone with some dolomite. Two distinct fossil assemblages are found in the second member. The older Luoping biota preserves abundant arthropods along with fossils from other invertebrates and vertebrates, which are rare but well-preserved. The slightly younger Panxian fauna has a more diverse and common assortment of marine reptiles such as sauropterygians.[1]
Fossil content
Among others, the following fossils were reported from the formation:
References
- Benton, Michael J.; Zhang, Qiyue; Hu, Shixue; Chen, Zhong-Qiang; Wen, Wen; Liu, Jun; Huang, Jinyuan; Zhou, Changyong; Xie, Tao; Tong, Jinnan; Choo, Brian (2013-10-01). "Exceptional vertebrate biotas from the Triassic of China, and the expansion of marine ecosystems after the Permo-Triassic mass extinction". Earth-Science Reviews. 125: 199–243. doi:10.1016/j.earscirev.2013.05.014. ISSN 0012-8252.