Coal clasts associated with extreme floods are prone to survive and maintain their large size, contrary to the general belief that distance from the parent peat layer reduces the size of transported clasts. Contrary to apparent logic, moreover, a second flood event favors the preservation potential of such soft organic clasts, this being the minimal fragmentation. An Anthropocene example from an urban park in Spain demonstrates that peat clasts up to 1 m long can survive due to flotation for a distance of almost a hundred meters and are well preserved and stabilized thanks to a second flood. These peat blocks were generated by catastrophic flooding of urban peatlands along the Ebro River (city of Zaragoza) during exceptional rainfalls in Iberia. The water flow from the Ebro River flooded the peatland at the surface of the meander, ripping up peat clasts from a shear or detachment level formed by an indurated level characterized by rounded quartzite pebbles, which acted as a hydrological discontinuity surface. Extensive evidence of the paleoflow direction is provided by oriented crushed reeds and the widespread occurrence of imbricated and thrusted peat blocks on the eroded and exposed peatland and in the main urban accumulation areas. To be specific, peat blocks and minor clasts accumulated in four areas associated with different modes of transport and topographic steps. From proximal to distal these are as follows: i) a proximal rim including thrusted peat blocks on the eroded peatland, ii) two intermediate accumulation zones associated with topographic steps in the park, characterized by peat-clast imbrication, iii) gravity-fall peat clasts deposited in an artificial channel in the park, and iv) peat rafts of more than 1 m in diameter scattered over the surface of the park (at a distance of 90 m from the eroded peatland).

中文翻译：

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与极端洪水有关的泥炭块：类似于古代煤形成环境的人类世类似物

与一般洪水有关的煤屑易于幸存并保持其大尺寸，这与人们普遍认为与母泥炭层的距离减小了所运输的煤屑的尺寸相反。此外，与明显的逻辑相反，第二次洪水事件有利于此类软有机碎屑的保存潜力，这是最小的碎裂。来自西班牙城市公园的人类世时代的一个例子表明，长达1 m的泥炭碎屑可以通过浮选幸存下来近一百米的距离，并且由于第二次洪水而得到了很好的保存和稳定。这些泥炭块是在伊比利亚的特大降雨期间，沿埃布罗河（萨拉戈萨市）的城市泥炭地遭受灾难性洪水而产生的。埃布罗河（Ebro River）流出的水淹没了河曲表面的泥炭地，从以水平的石英岩卵石为特征的坚硬水平形成的剪切或分离水平撕裂泥炭屑，充当水文不连续性表面。定向破碎的芦苇以及在侵蚀和裸露的泥炭地上以及在主要的城市聚集区广泛存在着带状和带状泥炭块，为古流向提供了广泛的证据。具体而言，泥炭块和次要碎屑堆积在与不同运输方式和地形步骤相关的四个区域中。从近端到远端如下：i）在受侵蚀的泥炭地上包括推挤泥炭块的近缘，ii）与公园中地形阶梯相关的两个中间堆积区，其特征是泥炭一碎屑成岩作用，