Postglacial Isostatic Movement in Northeastern Devon Island: A Reappraisal

Abstract

Amended emergence and uplift curves are presented for the Truelove Inlet area. The new curves are based mainly on radiocarbon dates from whalebone, driftwood and basal peat. The marine limit lies at 76 m a.s.l., and dates to approximately 9450 BP, which is also considered to be the date of deglaciation; total postglacial uplift is 107 m. The rate of uplift during the first thousand years following deglaciation reached 4.05 m per century, which is markedly less rapid than was previously reported. The rate of uplift decreased steadily thereafter and, at present, appears to be matched by eustatic sea level rise. What had appeared to be fossil evidence of restrained rebound at the onset of uplift was probably due to accidental mixing during collection of interstadial shells with postglacial shells. The total amount of postglacial uplift, and the rates of uplift, have probably been somewhat suppressed by the close proximity of the Devon Island Ice Cap.