Abstract While recent landscape changes can be usually easily read through accessible morphological features, relatively ancient processes can be difficult to detect as the associated morphologies and deposits are often buried below younger sediments. With the aim of understanding the evolution of the distal Venetian-Friulian Plain (NE Italy) after the Last Glacial Maximum (LGM), this work presents the analysis performed on a dataset of ca. 2300 mechanical and hand-made cores, which allowed a detailed reconstruction of the formation and evolution of an incised valley, now almost completely filled and with little to absent morphologic expression. Such valley, up to 1.2 km wide, with a depth of 20 m below the LGM alluvial plain and traced for a length of 25 km, is the result of the complex interplay between minor spring-fed rivers and the Tagliamento River. The detailed characterization of the infilling allowed to identify two main phases in the valley evolution. The first one is related to the activity of the paleo Tagliamento River and led to the deposition of a 10 m thick gravelly unit (ca. 19–9.5 ka cal BP). The second phase, which followed a disconnection of the Tagliamento, is linked to the Holocene marine transgression and led to the formation of a lagoon environment within the valley and to the deposition of a ca. 15 m thick unit of lagoon muds (ca. 8 ka cal BP - historic time). This latter unit lays on top of gyttja deposits, indicating for the first time in this area the presence of widespread lacustrine environments in the Early Holocene. This work presents an in-depth analysis on the evolution of a distal plain incised valley, from its formation to its final filling, providing at the same time the means to describe the development of the entire alluvial plain landscape, spanning from the end of the LGM to the middle Holocene. We present new data on the paleoenvironmental and morphologic evolution of the Venetian-Friulian Plain area as a consequence of the interplay between autogenic forces and sea-level rise. Our study allowed to understand the importance of both Alpine rivers and groundwater-fed streams in the formation of large incised valleys in the coastal sector of the whole Venetian-Friulian Plain. Finally, as during the transgressive phase the upstream sediment input in the valley was almost absent, this study provides insights into facies and architecture of a rare example of downstream-controlled filling of an incised valley.

中文翻译：

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Concordia Sagittaria（塔利亚门托河，意大利东北部）埋藏下切河谷的晚第四纪景观演化：切口和海侵的重建

摘要 虽然最近的景观变化通常可以通过可访问的形态特征轻松读取，但相对古老的过程可能难以检测，因为相关的形态和沉积物通常被掩埋在较年轻的沉积物之下。为了了解末次盛冰期 (LGM) 后威尼斯 - 弗留利平原 (意大利东北部) 的远端演变，这项工作介绍了对约 . 2300 个机械和手工制作的核心，允许详细重建下切山谷的形成和演变，现在几乎完全填充并且几乎没有形态表达。这样的山谷，宽达 1.2 公里，深达 20 米，位于 LGM 冲积平原下方，追踪长度为 25 公里，是小河流和塔利亚门托河之间复杂相互作用的结果。填充物的详细特征可以确定山谷演化的两个主要阶段。第一个与古 Tagliamento 河的活动有关，导致沉积了 10 m 厚的砾石单元（约 19-9.5 ka cal BP）。在 Tagliamento 断开之后的第二阶段与全新世海侵有关，并导致山谷内泻湖环境的形成和约 100 米的沉积。15 m 厚的泻湖泥浆单元（约 8 ka cal BP - 历史时间）。后一个单元位于 gyttja 沉积物的顶部，首次表明该地区在全新世早期存在广泛的湖泊环境。这项工作对远端平原下切谷从形成到最终填埋的演变进行了深入分析，同时提供了描述整个冲积平原景观发展的手段，从整个冲积平原的尽头开始。 LGM到全新世中期。由于自生力与海平面上升之间的相互作用，我们提供了有关威尼斯-弗留利平原地区古环境和形态演变的新数据。我们的研究使人们能够了解高山河流和地下水源溪流在整个威尼斯 - 弗留利平原沿海地区形成大型下切山谷的重要性。最后，由于在海进阶段几乎没有上游沉积物进入山谷，