Postglacial palaeoenvironmental reconstruction of the Fury and Hecla Strait region (Nunavut) inferred from microfossils and geochemical proxies

Abstract

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.

Quaternary environmental and climatic history of the northern high latitudes – recent contributions and perspectives from lake sediment records

“…From these lakes, Adaimé et al . (2022) studied two short cores using a multiproxy approach involving radiocarbon dating, lithochemical and diatom analyses. The results shed new light on the timing of regional deglaciation, and on subsequent marine inundation, isostatic uplift and temperature changes throughout the past 9 ka.…”

“…Also on the North American mainland, but much further east, lakes Fury-1 and -2 are located along the southern shore of the Fury and Hecla Strait, between the Melville Peninsula and Baffin Island. From these lakes, Adaimé et al (2022) studied two short cores using a multiproxy approach involving radiocarbon dating, lithochemical and diatom analyses. The results shed new light on the timing of regional deglaciation, and on subsequent marine inundation, isostatic uplift and temperature changes throughout the past 9 ka.…”

Application of Metabolomics for the Detection and Evaluation of Cyanopeptide Mixtures in Ontario and Quebec Lakes

“…A wide range of indicators are routinely employed in paleoenvironmental studies to determine anthropogenic changes, hydrological conditions and land-use impacts. Frequently, geochemical and organic matter analyses are applied as paleolimnological proxies [223][224][225] . Within the last few decades, Xray fluorescence (XRF) core scanners have become increasingly utilized in for geochemical analyses in paleoenvironmental research.…”

“…32). Furthermore, Adaïmé et al (2022) observed a high correlation between the Ca/Ti and organic matter content 225 . An increase in both biological sedimentation and high organic matter content is facilitated by productive, anoxic and hydraulically saturated conditions, representative of the pre-canal wetland.…”