Sedimentary processes in a microbial flat, developed in a progradational environment and trampled by vertebrates, were monitored under varying energy conditions. A vertebrate footprint made on the sedimentary surface was selected and was kept under observation for two years visited on nine field trips. Thus, this contribution provides a detailed analysis of the evolution of a microbial tidal flat with high-sediment-flux events and contributes to a better understanding of the sedimentary processes involved in the preservation of a true track. This study demonstrates that the formation of biolaminites (sequence of microbial mats interbedded with sand layers) in the coastal environment is caused by episodic pulses in the hydrodynamic regime of the area. Through the detailed inspection of a cross section of a sedimentary block containing the vertebrate footprint, the sedimentation history since the footprint creation is unravelled in relation to hydrodynamic records. Water energy was inferred using the measurements of a water-level sensor located on the tidal flat recording continuously every 10 minutes. The results indicate that the seawater enters into the zone by floods that occur during storm surges, reaching up to 70 cm height in the water column, and transporting abundant sediment, which produces the deposition of flat sand layers or sand ripples on the microbial mats. A sedimentation rate of 0.32 to 0.41 cm per year was calculated along the two-years monitoring. The study recognizes the plastic behavior of the microbial mat, one of their most important rheological properties, as a response to the registration of a vertebrate footprint. Petrographic analysis of microbial-mat layers reveals the precipitation of thin carbonate laminae during periods of seawater evaporation, which may enhance the preservation of sediments. Episodic sediment transport, in addition to the presence of a microbial-mat, creates the perfect conditions for formation, early burial, and preservation of the footprint in siliciclastic sediments.

中文翻译：

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微生物垫和高沉积速率在硅质碎屑滩涂早期埋葬和足迹保护中的作用

在变化的能量条件下监测了微生物在一个渐进的环境中发育并被脊椎动物践踏的沉积过程。选择在沉积表面上形成的脊椎动物足迹，并在九次实地考察中进行了两年的观察观察。因此，该贡献提供了对具有高沉积物通量事件的微生物潮滩的演化的详细分析，并有助于更好地了解保存真实航迹所涉及的沉积过程。这项研究表明，沿海环境中生物薄片的形成（微生物垫层与沙层交错排列）是由该地区水动力状态中的偶发性脉冲引起的。通过详细检查包含脊椎动物足迹的沉积块的横截面，可以了解与水动力记录有关的足迹历史，因为足迹的产生尚未得到阐明。使用每10分钟连续测量位于潮滩记录上的水位传感器的测量结果来推断水能。结果表明，海水通过暴风雨期间的洪水进入该区域，到达水柱高度达70厘米，并输送大量的沉积物，从而在微生物垫上沉积出平坦的沙层或沙波纹。根据两年的监测，每年的沉积速率为0.32至0.41 cm。这项研究认识到微生物垫的塑性行为是其最重要的流变特性之一，作为对脊椎动物脚印注册的回应。微生物垫层的岩石学分析表明，在海水蒸发期间，薄碳酸盐薄层的沉淀，这可能会增强沉积物的保存。除了存在微生物垫外，间歇性沉积物的运输还为硅质碎屑沉积物的形成，早期埋葬和保留足迹创造了理想的条件。