Late quaternary marine fossils from frobisher bay (Baffin Island, N.W.T., Canada)

Abstract

Eighteen species of fossil marine pelecypod and eighteen species of Foraminefera collected from raised beach deposits (with strandlines at 27 ft., 48 ft. and 77 ft. above sea-level) at Frobisher Bay, yield possible evidence of postglacial changes in the marine environment. A few of the little-known species of pelecypod are described. Six of the species are recorded for the first time in raised marine deposits of arctic Canada: two are pan-arctic species (i.e., Axinopsida orbiculata and Yoldia fraterna) and three species (i.e., Volsella demissa, Nucula delphinodonta, Lyonsia hyalina) do not occur in Canadian arctic waters at the present time and suggest more favourable environmental conditions during the Atlantic climatic phase. The present distribution of the other species, Yoldia sapotilla, is still uncertain. The presence in sediments at 21 ft. above sea level of temperate Foraminifera Globuina inaequalis and the pelagic Foraminifera Orbulina universa may also point to warmer conditions about 6,000–6,500 years ago. Radiocarbon datings of 6,140 ± 170 and 6,440 ± 160 years B.P. were determined on shells from 48 ft. and 11 ft. above sea-level respectively. The latter date indicates the upper part of Frobsher Bay was deglaciated at least 6,500 years ago, while the former date suggests an average land emergence of about 1 ft./century in the last 6,000 years.