Lateglacial and Holocene sedimentary dynamics in northwestern Baffin Bay as recorded in sediment cores from Cape Norton Shaw Inlet (Nunavut, Canada)

• Published in: Boreas
• Main Authors: Stevenard, Nathan, Montero-Serrano, Jean-Carlos, Eynaud, Frédérique, St-Onge, Guillaume, Zaragosi, Sébastien, Copland, Luke
• Other Authors: Laboratoire des Sciences du Climat et de l'Environnement Gif-sur-Yvette (LSCE), Université de Versailles Saint-Quentin-en-Yvelines (UVSQ)-Commissariat à l'énergie atomique et aux énergies alternatives (CEA)-Institut national des sciences de l'Univers (INSU - CNRS)-Université Paris-Saclay-Centre National de la Recherche Scientifique (CNRS), Environnements et Paléoenvironnements OCéaniques (EPOC), Observatoire aquitain des sciences de l'univers (OASU), Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-Université Sciences et Technologies - Bordeaux 1 (UB)-Institut national des sciences de l'Univers (INSU - CNRS)-Centre National de la Recherche Scientifique (CNRS)-École Pratique des Hautes Études (EPHE), Université Paris sciences et lettres (PSL)-Université Paris sciences et lettres (PSL)-Centre National de la Recherche Scientifique (CNRS), Institut des Sciences de la MER de Rimouski (ISMER), Université du Québec à Rimouski (UQAR), University of Ottawa Ottawa, ArcticNet; Natural Sciences and Engineering Research Council of Canada, NSERC; Université de Bordeaux, We are grateful to the captain, officers, crew and scientists onboard the CCGS during the 2018 (Leg 3) ArcticNet expedition for the recovery of the sediment cores used in this study. We also thank Quentin Beauvais (ISMER‐UQAR), Maria‐Emilia Rodriguez‐Cuicas (ISMER‐UQAR), Marie Girieud (ISMER‐UQAR), Nicolas Van Nieuwenhove (University of New Brunswick), Marie‐Claire Perello (Université de Bordeaux) and Margaux Saint George (Université de Bordeaux) for their technical support and advice in the laboratory. The authors declare that they have no conflicts of interest. Last, we thank Kelly Hogan and John T. Andrews for their constructive reviews, which helped to improve the quality of the manuscript, as well as to Jan A. Piotrowski for his editorial work. This research was funded by ArcticNet (a Network of Centers of Excellence Canada), Québec‐Océan, GEOTOP and the Natural Sciences and Engineering Research Council of Canada (NSERC) through discovery grants to J.‐C. Montero‐Serrano and G. St‐Onge. Amundsen
• Format: Article in Journal/Newspaper
• Language: English
• Published: HAL CCSD 2022
• Subjects: [SDE.MCG]Environmental Sciences/Global Changes; Arctic; Baffin Bay; Canada; Cape Norton; Cape Norton Shaw; Kennedy Channel; Manson Icefield; Nares; Nunavut; Baffin; glacier*; Iceberg*; Kennedy channel; Nares strait; Sea ice
• Online Access: https://hal.science/hal-03775777; https://hal.science/hal-03775777/document; https://hal.science/hal-03775777/file/Boreas%20-%202021%20-%20Stevenard%20-%20Lateglacial%20and%20Holocene%20sedimentary%20dynamics%20in%20northwestern%20Baffin%20Bay%20as%20recorded%20in.pdf; https://doi.org/10.1111/bor.12575

International audience The physical, sedimentological, mineralogical and elemental geochemical properties of sediment cores AMD1803-02BC and 01PC from the Cape Norton Shaw Inlet were investigated to reconstruct glacial sediment discharges from southeastern Manson Icefield and document the impact of ice–ocean interactions on the sediment dynamics and opening of the North Water Polynya (NOW) in northwestern Baffin Bay since the last deglaciation. Laminated glaciomarine sediments rich in quartz and feldspar are observed prior to 11 cal. ka BP and were probably deposited by hyperpycnal currents triggered by the local retreat of the southern margin of the Innuitian Ice. Detrital proxies suggest that Early Holocene sediment dynamics were mainly influenced by sea ice and iceberg rafting and meltwater discharges related to the deglaciation of eastern Smith (~11 to 10.65 cal. ka BP) and Jones (~10.7 cal. ka BP) sounds. This also provides an upper limit to the timing of formation of the NOW. The high detrital carbonate contents during 8.8 to 6.6 cal. ka BP confirm that enhanced carbonate-rich sediment export from Nares Strait to northern Baffin Bay occurred during and after the deglaciation of Kennedy Channel (8.8 to 8.2 cal. ka BP). Canadian Shield sediment inputs have dominated since 6.6 cal. ka BP, indicating that sedimentation is mainly influenced by Cape Norton Shaw glacier discharges. The lower level of sedimentation recorded in core 01PC during the Middle to Late Holocene suggests an accelerated landward retreat of the Cape Norton Shaw glaciers in response to warmer marine conditions. During the Neoglacial period, higher sedimentation rates and detrital proxies in the cores suggest increased glacial erosional processes, probably associated with the long-term declines in boreal summer insolation and glacier growth. Finally, mineralogical and grain-size data in core 02BC support the idea that increased Arctic atmospheric temperatures have had an important influence on the glacial dynamics during the industrial ...