Fig. 1: Stratigraphic succession of the Yu’anshan Formation, showing lithologic log, bioturbation index, and the distribution of the dominant deposits. | Nature Communications

Fig. 1: Stratigraphic succession of the Yu’anshan Formation, showing lithologic log, bioturbation index, and the distribution of the dominant deposits.

From: The Chengjiang Biota inhabited a deltaic environment

Fig. 1: Stratigraphic succession of the Yu’anshan Formation, showing lithologic log, bioturbation index, and the distribution of the dominant deposits.The alternative text for this image may have been generated using AI.

OF oscillatory-flow deposits, HF hyperpycnal flow deposits, WEFM wave-enhanced fluid mud deposits, PF-TC plug flow, low-density turbidity current deposits, and H hemipelagic deposits. VF very fine, F fine, M medium, C coarse, VC very coarse. Note the clear large-scale coarsening- and thickening-upward trend that is common in wave-influenced shallow-marine depositional systems, including most notable deltas. The so-called “Upper Siltstone Member” is actually sandstone-dominated.

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