Abstract Lacustrine sedimentary records are valuable archives of regional paleoenvironmental and paleoclimatic changes. High-resolution seismic reflection data collected in 2013, in conjunction with data from sediment core Co1309, provide a detailed reconstruction of the preglacial and postglacial environmental and sedimentological history of Lake Ladoga (NW Russia) during the late Quaternary. The exceptionally good quality of the seismic data reveals an up to 90-m-thick sedimentary infill in undisturbed places, containing four distinct sequences documented in unprecedented detail. The deepest sequence S1 most likely represents the bedrock of the lacustrine basin, which was reshaped during the subsequent glaciations. The overlying sequence S2 contains large-scale mounds of variable dimension, shape and internal architecture, which suggest a complex history of formation and deformation. We interpret these mounds as a moraine-mound complex resulting from thrusting and bulldozing processes of pre-existing, subglacial sediments during the overall retreat of the Scandinavian Ice Sheet following the Last Glacial Maximum. The finely-layered sequence S3 coincides with varved sediments in core Co1309 that mark the Scandinavian Ice Sheet deglaciation in the Ladoga basin. The youngest sequence S4, characterised by a semi-transparent facies in the acoustic data, coincides with lacustrine sediments in core Co1309 that were deposited during the Holocene. Our results also document major thoroughgoing fault systems in the northwestern part of the lake basin, along with unconformities related to lake-level fluctuations, notably in the eastern-, western- and southernmost regions. By coupling hydroacoustic and sedimentological data, we are able to pinpoint lateral variations and modifications of sedimentary inputs through time during the evolution of the Ladoga basin, along with unravelling the paleoenvironmental history of Lake Ladoga since the pre-LGM.

中文翻译：

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俄罗斯西北部斯堪的纳维亚冰盖的前冰河和冰河后历史——来自拉多加湖的证据

摘要 湖泊沉积记录是区域古环境古气候变化的宝贵档案。2013 年收集的高分辨率地震反射数据，结合来自沉积岩心 Co1309 的数据，详细重建了拉多加湖（俄罗斯西北部）晚第四纪的冰前和冰后环境和沉积学历史。异常优质的地震数据揭示了在未受干扰的地方有高达 90 米厚的沉积填充物，其中包含以前所未有的详细记录的四个不同序列。最深的序列 S1 很可能代表了湖盆的基岩，它在随后的冰川作用中被重塑。上覆序列 S2 包含可变尺寸、形状和内部结构的大型土堆，这表明形成和变形的复杂历史。我们将这些土丘解释为一个冰碛丘复合体，是在末次冰期极大期之后斯堪的纳维亚冰盖整体退缩期间预先存在的冰下沉积物的冲撞和推土过程造成的。细层层序 S3 与 Co1309 核心中的变质沉积物一致，标志着拉多加盆地的斯堪的纳维亚冰盖冰川消退。最年轻的层序S4，以声学数据中的半透明相为特征，与全新世沉积的Co1309核心的湖相沉积物一致。我们的结果还记录了湖盆西北部的主要断层系统，以及与湖水位波动相关的不整合面，特别是在东部、西部和最南端地区。