The Dongpo Formation is an Ediacaran aged geologic formation in the Henan Province of Central China. It is also fossiliferous in nature, containing fossils which date it to the Nama assemblage.
Geology
The Dongpo Formation can be found within the North China Craton, currently amongst the oldest known cratons in the world, alongside its southern edge. The formation itself is primarily composed of yellowish-green shale, siltstone, and fine-grained sandstone.[1]
It is unconformably overlain by the sandstone Cambrian aged Xinji Formation, meanwhile it is conformably underlain by the older glacial Luoquan Formation.[1]
Paleobiota
The formation is dominated by macroalgae forms, like Glomulus, alongside tubular forms such as Wutubus and Shaanxilithes. There are also some Ediacaran-type fossils, and some rare trace fossils, all of which has helped to constrain the age of the formation to the terminal Ediacaran, between 550 Ma and 538.8 Ma.[1]
The reported frondose forms from the formation have had their biotic origins put into question, as some researchers suggest that they may actually be chevron marks produced by clasts being transported above the seabed, due to their similarity with other tool marks found in other formations, such as the Carboniferous aged Gull Island Formation in Ireland.[2]
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Notes
Uncertain or tentative taxa are in small text; crossed out taxa are discredited.
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incertae sedis
Flora
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| Glomulus[1]
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Filamentous cyanobacteria.
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Microorganisms
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| Acanthomorphic acritarchs[4]
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Acritarchs.
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Ichnogenera
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| Archaeonassa[1]
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Burrows.
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Undescribed
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| Unnamed frondose fossils[1]
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Slender frondose fossils, which bear some similarities with petalonamids, although poor preservation makes proper taxonomic assignment difficult. May be sedimentary markings produce by transported clasts.[2]
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See also
References
- ^ a b c d e f g h i j k l m Wang, Xin; Zhang, Xingliang; Dai, Tao; Liu, Wei; Zhang, Yuan; Li, Luoyang (March 2026). "New occurrence of a postglacial Ediacaran macrofossil assemblage from North China and its evolutionary implication". Precambrian Research. 434 107992. doi:10.1016/j.precamres.2025.107992.
- ^ a b McIlroy, Duncan; Peakall, Jeffrey (May 2026). "Comment on "New occurrence of a postglacial Ediacaran macrofossil assemblage from North China and its evolutionary implication" by Wang et al. (2026), Precambrian Research 434, 107992". Precambrian Research. 436 108041. doi:10.1016/j.precamres.2026.108041.
- ^ Wang, Xin; Zhang, Xingliang; Liu, Wei (October 2021). "Biostratigraphic constraints on the age of Neoproterozoic glaciation in North China". Journal of Asian Earth Sciences. 219 104894. doi:10.1016/j.jseaes.2021.104894.
- ^ Chumakov, N. M. (August 2009). "The Baykonurian glaciohorizon of the Late Vendian". Stratigraphy and Geological Correlation. 17 (4): 373–381. doi:10.1134/S0869593809040029.