Hanging Rocks Formation
| Hanging Rocks Formation | |
|---|---|
| Stratigraphic range: Ediacaran | |
| Type | Formation |
| Unit of | Maplewell Group |
| Sub-units | Hallgate and Sliding Stone Slump Breccia Members |
| Underlies |
|
| Overlies | Bradgate Formation[2] |
| Thickness | 50 m (164 ft)[1] |
| Lithology | |
| Primary | Tuff |
| Other | Graywacke |
| Location | |
| Region | Leicestershire |
| Country |  United Kingdom |
| Type section | |
| Named for | Bradgate Park |
The Hanging Rocks Formation is a geologic formation in Leicestershire, and is the youngest and smallest of the Maplewell Group and the larger Charnian Supergroup which it is apart of. Due to this, and the fact that the rocks are not well exposed at both the top and base,[1] there have been no Ediacaran fossils found to date, unlike the two underlying Bradgate and Beacon Hill Formations.
Dating
[edit]Despite the poor exposure of the formation, scientists were able to collect zircon crystals from the lower parts of the formation, allowing them to perform zircon U-Pb dating, which recovered a date of 556±6.4 Ma, close to the Bradgate Formations top age of 557 Ma. It is noted that the top of the formation is capped at a zircon age of roughly 550 Ma,[1] which is just before the first formations of the Nama assemblage were deposited.
References
[edit]- Various Contributors to the Paleobiology Database. "Fossilworks: Gateway to the Paleobiology Database". Retrieved 17 December 2021.
- ^ a b c d Noble, Stephen R.; Condon, Daniel J.; Carney, John N.; Wilby, Philip R.; Pharaoh, Timothy C.; Ford, Trevor D. (January 2015). "U-Pb geochronology and global context of the Charnian Supergroup, UK: Constraints on the age of key Ediacaran fossil assemblages". Geological Society of America Bulletin. 127 (1–2): 250–265. doi:10.1130/B31013.1.
- ^ a b Moseley, John; Ford, Trevor. "The Sedimentology of the Charnian Supergroup" (PDF). Mercian Geologist.
- ^ McILROY, D.; Brasier, M. D.; Moseley, J. B. (March 1998). "The Proterozoic–Cambrian transition within the 'Charnian Supergroup' of central England and the antiquity of the Ediacara fauna". Journal of the Geological Society. 155 (2): 401–411. doi:10.1144/gsjgs.155.2.0401.