Yixian Formation
| Yixian Formation | |
|---|---|
| Stratigraphic range: Barremian ~ | |
An hillside showing an outcrop of the Yixian Formation's Lujiatun Member | |
| Type | Geological formation |
| Unit of | Jehol Group |
| Sub-units | Jianshangou Bed Lujiatun Bed |
| Underlies | Jiufotang Formation |
| Overlies | Dabeigou Formation, Zhangjiakou Formation, Tuchengzi Formation |
| Lithology | |
| Primary | Basalt |
| Other | Siliciclastic |
| Location | |
| Coordinates | 41°31′59″N 121°14′18″E / 41.5330°N 121.2383°E |
| Approximate paleocoordinates | 44°18′N 122°48′E / 44.3°N 122.8°E |
| Region | Liaoning |
| Country | China |
| Type section | |
| Named for | Yixian, Liaoning |
| Named by | Amadeus William Grabau |
| Year defined | 1923 |
The Yixian Formation (simplified Chinese: 义县组; traditional Chinese: 義縣組; pinyin: Yìxiàn zǔ; formerly transcribed as Yihsien Formation or Yixiang Formation) is a geological formation in Jinzhou, Liaoning, People's Republic of China, that spans the Barremian stage of the Early Cretaceous. It is known for its exquisitely preserved fossils, and is mainly composed of basalts interspersed with siliciclastic sediments.