Identifying glacio–isostatic rebound processes using testate amoeba as palaeohydrological proxies; a case study from subarctic Québec, Canada

  • Crystal FERGUSON
  • Florin PENDEA
Keywords: glacio–isostasy, wetland hydrology, paleoecology, testate amoebae, Transfer Function, radiocarbon dating

Abstract

Glacio–isostatic rebound is one of the most important landscape processes affecting the northern and northeastern coast of Canada and, therefore, reconstruction of postglacial rebound rates is critical for a better understanding of landscape evolution in this region. Yet, studies reconstructing coastal palaeogeography in Northern Canada
are constrained by the limitation of shell–based radiocarbon chronologies used in dating shoreline displacement
and palaeo–sea levels. This study proposes an alternative methodology for the reconstruction and dating of palaeo–sea levels, which uses testate amoeba microfossils from coastal sediments as palaeoecological markers of
coastal water table shifts linked to sea level change. Our results indicate that testate amoeba–inferred water table
reconstruction is a good indicator of water table drawdown due to isostatic uplift on affected coastlines. Furthermore, radiocarbon dating of distinct plant macrofossils within the transitional marine/freshwater stratigraphy
avoids the inherent reservoir effect issues associated with dating of marine shells.

Published
2018-12-28
Section
Articles