A late holocene pollen diagram from pangnirtung pass, Baffin Island, N.W.T., Canada

Abstract

A 1.2 m section of organic-rich sediment from near Windy Lake, Pangnirtung Pass, Baffin Island, Canada, is dated by twelve radiocarbon assays which indicate that the sediment accumulated at an average rate of 6.5 cm 100 yr −1. The base of the studied exposure is about 2500 years old, whereas the sediment at a depth of 4 to 9 cm is dated about 650 years old. The sampling interval for pollen averages one sample every 39 years. The section is described in terms of the lithology of the inorganic matrix, in the plant growth form and moisture preference of the pollen taxa, and in the variations in the influx of exotic pollen ( Alnus, Picea, and Pinus). Principal Components Analysis and clustering of pollen levels were used to zone five different groupings of the pollen taxa “objectively”. Both relative and “absolute” pollen values were used in these various steps. Pollen accumulation varied between 24 and 14,300 grains cm −2 yr −1 with a median value of 501. Thirteen biozones are recognized primarily from changes in the rates of pollen accumulation and diversity. The broad climatic interpretation of the pollen stratigraphy has similarities and differences from nearby glacial moraine chronologies. Sharp increases in exotic pollen (especially Alnus) are provisionally associated with major advection of southerly air toward Cumberland Peninsula, southeastern Baffin Island.