Radiogenic isotopes on marine sediments from the Baffin Bay : implications for the sediment supply during the last deglaciation

• Main Author: Kirillova, Valeriia
• Other Authors: Kasemann, Simone, Stein, Rüdiger
• Format: Doctoral or Postdoctoral Thesis
• Language: English
• Published: Universität Bremen 2017
• Subjects: Baffin Bay; Last Deglaciation; Radiogenic isotopes; Neodymium; Iron-manganese coatings; Arctic; Paleoclimate; 550; 550 Earth sciences and geology; ddc:550; Arctic Ocean; Baffin Island; Canadian Arctic Archipelago; Greenland; Arctic Archipelago; Baffin; Climate change; Ice Sheet; Labrador Sea
• Online Access: https://media.suub.uni-bremen.de/handle/elib/1343; https://nbn-resolving.org/urn:nbn:de:gbv:46-00106270-10

The Baffin Bay is a marginal sea of the Atlantic Ocean, a semi-enclosed basin, situated between Greenland, Baffin Island and the Canadian Arctic Archipelago (CAA). It is an important link in the Northern Hemisphere circulation and is connected to the Arctic Ocean and to the Labrador Sea. During the Last Glacial Maximum (LGM) the Baffin Bay was flanked by three North American Ice sheets: Laurentide, Innuitian and Greenland. Ice sheet dynamics is still poorly understood but highly valuable in the frame of recent Greenland ice sheet mass loss and recent climate change data. Understanding the mechanisms and interplay between ice sheets, ocean circulation and climate is a key to more accurate climate prediction models. Thus the deglaciation history of the Baffin Bay is a matter of interest for the research community and has been a topic for many projects in the last decades. There is a gap, however, in a thorough provenance study, which would contribute to the information on sediment supply in the Baffin Bay. Knowing the main sediment sources can further improve the research on ice sheet dynamics and paleocirculation. For this project three cores were investigated: one in the central (PC 16) and two in the southern Baffin Bay, along both eastern (SL 170) and western (SL 174) coasts. The location of these cores allows to characterize sediment provenance in the Baffin Bay as well as to reproduce transport mechanisms, in particular, water masses. The major research goal of the Ph.D project, therefore, is to perform a sediment provenance study in the Baffin Bay based on radiogenic isotope analyses (Sr, Nd, Pb) on the detrital fraction of the sediment cores and to connect these results with the information on sediment delivery mechanisms and ice sheet extent/retreat. We were able to determine major sediment sources for the core SL 170: central West Greenland (Nagssugtoqidian Mobile Belt) and southern West Greenland (Archean Block) terrains. Moreover, we observed the shift in all three radiogenic isotope records at 12 ka ...