Holocene chronostratigraphy of northeastern Baffin Bay based on radiocarbon and palaeomagnetic data

Abstract

The northeastern Baffin Bay continental margin, which experiences high sediment accumulation rates, is an excellent location to study Holocene sedimentary variations. However, it is often difficult to obtain reliable chronologies of the sediment archives using traditional methods (δ18O and radiocarbon) due to specific oceanographic conditions (e.g. corrosive bottom waters). Here we propose a chronostratigraphy of three cores collected on the northwestern Greenland margin (AMD14-204, AMD14-210 and AMD14-Kane2B) based on a combination of radiocarbon dating and palaeomagnetic records. Geophysical properties of discrete samples were used to verify the reliability of the palaeomagnetic records. Palaeomagnetic analyses indicate a strong and stable natural remanent magnetization carried by low coercivity ferrimagnetic minerals (magnetite) in the pseudo-single domain grain size range. Correlation of the full palaeomagnetic vector (inclination, declination, and relative palaeointensity) was used to establish a reliable chronostratigraphical framework for two of the cores (AMD14-204 and AMD14-210) and to propose an original palaeomagnetic record for the previously 14C-dated core AMD14-Kane2B that covers most of the Holocene. Overall, this new chronostratigraphy allowed improvement of the timing of the main palaeoenvironmental changes that occurred in this area during the Holocene.