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Oriented-lake development in the context of late Quaternary landscape evolution, McKinley Bay Coastal Plain, western Arctic Canada
Quaternary Science Reviews ( IF 4 ) Pub Date : 2020-08-01 , DOI: 10.1016/j.quascirev.2020.106414
Stephen Wolfe , Julian Murton , Mark Bateman , John Barlow

Abstract Oriented lakes—characterized by elongate forms, central basins and shallow littoral shelves—are common features of circum-arctic coastal lowlands. The environmental conditions, geological processes and chronology associated with the development of oriented lakes, however, are little known but essential for understanding how such Arctic lowlands evolve. Using combined techniques of field and drill-log stratigraphy and sedimentology, luminescence and radiocarbon dating methods and geomorphic mapping, we reconstruct the landscape evolution leading toward oriented-lake formation on the McKinley Bay Coastal Plain of western Arctic, Canada—a region with over 900 oriented lakes. Most lakes with deep central basins are inherited from a preglacial braidplain (ca. 73–27 ka) and alluvial braided-channel network that extended beyond the glacial limit (ca. 18.6–14.3 ka). Eolian erosion, active during the lateglacial and postglacial period (ca. 12.8–1.9 ka), reworked fluvial deposits. Eolian processes modified existing basins and created other shallow deflationary basins, as small barchanoid dunes migrated under cold, dry paraglacial conditions between about 12.8 and 10.7 ka. Vegetation cover developed at the onset of the early Holocene climatic optimum ca. 10.7 ka, and parabolic dunes were active between 9.6 and 4.6 ka. Thus, oriented lakes developed in basins conditioned by fluvial and eolian processes. In the absence of much near-surface ground ice, lateral expansion of deep-basin lakes and shallow stabilized deflationary basins predominated during the late Holocene through wind-induced wave and current processes. Overall, this sequence of oriented-lake formation does not support a thaw-lake cycle but, rather, small-basin evolution of a periglacial landscape.

中文翻译:

加拿大北极西部麦金利湾沿海平原晚第四纪景观演化背景下的定向湖泊开发

摘要 定向湖泊——以细长形式、中央盆地和浅岸陆架为特征——是环北极沿海低地的共同特征。然而,与定向湖泊的发展相关的环境条件、地质过程和年代学鲜为人知,但对于了解此类北极低地如何演变至关重要。利用野外和钻井测井地层学和沉积学、发光和放射性碳测年方法以及地貌测绘相结合的技术,我们重建了加拿大北极西部麦金利湾沿海平原朝向定向湖泊形成的景观演变——该地区拥有超过 900面向湖泊。大多数具有深中央盆地的湖泊都继承自冰前辫状平原(约 73-27 ka) 和冲积辫状河道网络,延伸超出冰川极限(约 18.6-14.3 ka)。在晚冰期和后冰期(约 12.8-1.9 ka)活跃的风成侵蚀重新加工了河流沉积物。风成过程改变了现有盆地并创造了其他浅层紧缩盆地,因为小型新月形沙丘在大约 12.8 至 10.7 ka 之间的寒冷干燥的冰河条件下迁移。植被覆盖在全新世早期气候最适气候开始时发展起来。10.7 ka,抛物线沙丘在 9.6 至 4.6 ka 之间活跃。因此,定向湖泊发育在受河流和风成过程制约的盆地中。在没有很多近地表地冰的情况下,在全新世晚期,通过风引起的波浪和电流过程,深盆地湖泊和浅层稳定的紧缩盆地的横向扩张占主导地位。总体而言,这种定向湖泊形成序列不支持融湖循环,而是支持冰缘景观的小盆地演化。
更新日期:2020-08-01
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