Mall Bay Formation
| Mall Bay Formation | |
|---|---|
| Stratigraphic range: Ediacaran [1] | |
| Type | Formation |
| Unit of | Conception Group |
| Underlies | Gaskiers Formation[2] |
| Thickness | 1000 m (3,280 ft) |
| Lithology | |
| Primary | Siliciclastic siltstones |
| Other | Mudstone, Sandstone |
| Location | |
| Region |  Newfoundland |
| Country |  Canada |
 Outcrop distribution on Avalon peninsula, Newfoundland | |
The Mall Bay Formation is an Ediacaran formation, cropping out in Newfoundland and possibly elsewhere. It is part of the Conception Group, underlying the Gaskiers Formation.[2][1]
A recent study has found that this formation preserves evidence that the Gaskiers glaciation, which had previously been restricted to the Gaskiers Formation and only lasting roughly 1 million years, had actually begun a lot earlier than originally thought. This has been inferred through the discovery of glacial deposits like dropstones and clasts some 500 m below the Gaskiers base, giving the Gaskiers glaciation a duration of somewhere between 1.05 Ma to 4.8 Ma, up from the previous estimate of 350 ka to 1.6 Ma.[1]
References
[edit]- ^ a b c Fitzgerald, Danielle M.; Narbonne, Guy M.; Pufahl, Peir K.; Dalrymple, Robert W. (June 2024). "The Mall Bay Formation (Ediacaran) and the protracted onset of the Gaskiers glaciation in Newfoundland, Canada". Precambrian Research. 405: 107369. doi:10.1016/j.precamres.2024.107369.
- ^ a b A.G. Liu; D. McIlroy (September 2014). "Horizontal Surface Traces from the Fermeuse Formation, Ferryland (Newfoundland, Canada), and their Place within the Late Ediacaran Ichnological Revolution" (PDF). Geological Association of Canada - Special Paper (9).[dead link]