Liquefaction can cause deformation of unconsolidated sediment, but specific processes involved and the trigger mechanisms often remain obscured. This study describes multiple deformed sediment layers in a succession of lacustrine sand, silt and clay deposited during the Marine Isotope Stage 5d in north-western Lithuania. The deformation structures (load casts, pseudonodules, ball-and-pillow structures, broken-up laminae and injections) are embedded in ten separate layers of fine-grained, laterally continuous sediments. Detailed mesoscale sedimentological analyses suggest that each deformation event consisted of numerous successive stages of sediment advection facilitated by liquefaction. Low-permeability fine-grained laminae contributed to localized pore-water pressure build-up and lowering of sediment strength. Erosional top surfaces that truncate layers with soft-sediment deformation structures suggest that at least seven deformation events were separated by successive periods of initial erosion and then uninterrupted deposition in the lake. The most likely trigger of the deformation was recurrent palaeoseismic activity possibly linked to a late glacial isostatic adjustment following the Scandinavian Ice Sheet melting after the Saalian glaciation. This study emphasizes the potential role of seismic processes in shaping the sedimentary record of the intraplate region of north-eastern Europe and contributes to constraining the depth of liquefaction, regardless of the actual trigger mechanism.

中文翻译：

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立陶宛西北部地震引起的液化作用导致的晚更新世重复性软沉积物变形

液化会导致松散沉积物变形，但所涉及的具体过程和触发机制通常仍不清楚。本研究描述了立陶宛西北部海洋同位素阶段 5d 期间沉积的一系列湖相砂、粉砂和粘土中的多个变形沉积层。变形结构（载荷铸件、假结核、球枕结构、破碎的薄片和注入）嵌入十个单独的细粒、横向连续沉积层中。详细的中尺度沉积学分析表明，每个变形事件都由液化促进的多个连续的沉积物平流阶段组成。低渗透性细粒纹层导致局部孔隙水压力增加和沉积物强度降低。用软沉积物变形结构截断层的侵蚀顶面表明，至少有 7 个变形事件被连续的初始侵蚀和随后在湖中不间断的沉积所隔开。变形的最可能触发因素是反复发生的古地震活动，这可能与萨利冰川之后斯堪的纳维亚冰盖融化后的晚期冰川均衡调整有关。这项研究强调了地震过程在塑造东北欧板内区域的沉积记录方面的潜在作用，并有助于限制液化深度，而不管实际的触发机制如何。