An analysis of sediment records from two lakes located along the southeastern shore of the Fury and Hecla Strait (Nunavut, Canada) allowed us to reconstruct the regional environmental history since deglaciation. Multiproxy profiles, namely particle-size distribution, elemental geochemistry (based on X-ray fluorescence) and diatom assemblages, revealed a regional deglaciation and marine inundation around 8200 cal a bp. This suggests that glacial retreat in this region likely occurred several hundred years earlier than previously extrapolated. At that time, the connection between the Atlantic and Pacific Ocean currents must have been established and glacial isostatic adjustment gradually isolated the lacustrine basins from marine influence. Diatom assemblages revealed an abrupt marine–brackish–freshwater transition (ca. 6670–6130 cal a bp) through a shift in dominance from initial polyhalobian (e.g. Tabularia fasciculata, Navicula directa), intermediate mesohalobian (e.g. Cyclostephanos dubius, Thalassiosira baltica) to oligohalobian (fragilarioid Staurosirella pinnata, Staurosira venter, Pseudostaurosira pseudoconstruens, P. brevistriata) taxa. Multivariate analyses (redundancy analysis and multivariate regression tree) conducted on the biological and lithogeochemical data also suggest that climatic conditions may have remained relatively warm throughout the interval ~6000–3900 cal a bp, before significantly cooling over the past few millennia, as inferred from a decrease in organic matter accumulation and shifts in diatom communities.

中文翻译：

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从微化石和地球化学代理推断的弗瑞和赫克拉海峡地区（努纳武特）的冰后古环境重建

对位于富里和赫克拉海峡（加拿大努纳武特）东南岸的两个湖泊的沉积物记录进行分析，使我们能够重建自冰川消融以来的区域环境历史。Multiproxy 剖面，即粒度分布、元素地球化学（基于 X 射线荧光）和硅藻组合，揭示了 8200 cal a bp 左右的区域性冰川消融和海洋淹没。这表明该地区的冰川退缩可能比以前推断的要早几百年。那时，大西洋和太平洋洋流之间的联系肯定已经建立，冰川均衡调整逐渐将湖盆与海洋影响隔离开来。硅藻组合揭示了一个突然的海洋-微咸水-淡水转变（ ca. 6670-6130 cal a bp），通过从最初的多卤动物（例如Tabularia fasciculata、Navicula directa）、中间中卤动物（例如Cyclostephanos dubius、Thalassiosira baltica）到寡卤动物的优势转变。 （脆性类Staurosirella pinnata, Staurosira venter, Pseudostaurosira pseudoconstruens, P. brevistriata ) 分类群。对生物和岩石地球化学数据进行的多变量分析（冗余分析和多变量回归树）也表明，在过去几千年显着降温之前，气候条件可能在整个区间内保持相对温暖~6000-3900 cal a bp ，如从有机质积累的减少和硅藻群落的变化。