We used waterborne Ground Penetrating Radar (GPR) for mapping stratigraphic boundaries, sedimentation environments, and specific features of lacustrine sediments of postglacial Lake Polevskoye, which is located in Eastern Fennoscandia, near Lake Onega. The purpose of our study was to examine the spatial structure of the lacustrine sediments including particular facies represented by the thin interbedding of sand and clay in order to understand the conditions for their formation. The lake bottom morphology and stratigraphic boundaries beneath were mapped with a GPR with 150 MHz antenna unit and then made drill holes to verify GPR interpretations. The GPR measurements, verified by drilling, have vertical accuracy in the range of 0.12–0.36 m. We delineation specific GPR facies in the topmost part of varved clays and classified them as lacustrine turbidites by their structure and grain size. Further studies suggested that turbidites could be deposited by hyperpycnal flows during water discharge from glacial Lake Onega in the period 11.4–10.7 cal ka BP. The architectural implications of the turbidity current in the lake include localized layered sediments 0.5 m thick overlying an erosional surface, which contain unconformable sandy layers and plant debris. A GPR-based 3D model helped us to reconstruct the turbidity current direction, establish its confinement to a lake bottom depression, and consider the associated erosion processes. The near-bottom turbidity current passed through Lake Polevskoye from north to south, along with the bottom depression, and the eastern shore was eroded with a hydraulic jump. The hyperpycnal flows in the study site are associated probably with the last phase deglaciation of the terrain and a drop of the level of Lake Onega because these processes were the most prominent in recent geological history.

我们使用水载探地雷达 (GPR) 绘制冰后 Polevskoye 湖的地层边界、沉积环境和湖相沉积物的具体特征，该湖位于东芬诺斯坎迪亚，靠近奥涅加湖。我们研究的目的是检查湖相沉积物的空间结构，包括以砂和粘土的薄互层为代表的特定相，以了解它们的形成条件。湖底形态和下面的地层边界用带有 150 MHz 天线单元的 GPR 绘制，然后钻孔以验证 GPR 解释。经钻探验证的 GPR 测量具有 0.12-0.36 m 范围内的垂直精度。我们在斑纹粘土的最顶部描绘了特定的 GPR 相，并根据它们的结构和粒度将它们归类为湖相浊积岩。进一步的研究表明，在 11.4-10.7 cal ka BP 期间，奥涅加冰川湖的水排放过程中可能会通过超重流沉积浊积岩。湖中浊流对建筑的影响包括 0.5 m 厚的局部层状沉积物覆盖在侵蚀表面上，其中包含不整合的沙层和植物残骸。基于 GPR 的 3D 模型帮助我们重建浊流方向，确定其对湖底洼地的限制，并考虑相关的侵蚀过程。近底浊流自北向南流经波列夫斯科耶湖，沿底洼地，东岸因水跃而被侵蚀。研究地点的超重流可能与地形的最后阶段冰消作用和奥涅加湖水位下降有关，因为这些过程在最近的地质历史中最为突出。