Palynological study of a Mi'kmaw shell midden, Northeast Nova Scotia, Canada

Before now, no palynological studies were made on shell midden deposits in Nova Scotia, despite a long history of archaeological research. A test study of samples taken from the shell midden at Maligomish (Indian Island) on the Northumberland Strait was conducted to determine if sufficient pollen, fern and moss spores, and other non-pollen palynomorphs (NPP's, including fungal remains, algal spores) could be recovered to allow interpretation of environmental conditions at the time of deposition. Several pollen processing methods were tested: sieving and swirling, chemical treatment with cold HCl, 5% KOH and brief exposure to 5% NH4OH, and treatment with acetolysis solution. We recovered variable amounts of pollen, spores and NPP's from samples taken at 3-5 cm, 5-15 cm and 15-25 cm below surface. Abundant microcharcoal fragments prevented effective use of the swirling technique, but sufficient palynomorphs were recovered by chemical treatments to allow assessment of down-section changes in assemblages. Three radiocarbon ages from Mya arenaria and Crassostrea sp., and measurements of sediment grain size, moisture, organic and inorganic carbon, provide a framework for analysing palynological assemblage changes and context for interpreting differential palynomorph preservation. Despite some oxidation and microbial degradation of palynomorphs in the time interval (ca. 380 -1600 cal yr BP), the midden assemblages correlate with pollen zones from marine and lake core sites within ca. 50 km of Maligomish. Shifts in abundances of algal spores, testate amoebae and aquatic plant pollen also indicate changes in depositional conditions during the time of midden use. The study provides the first reference for archaeologists attempting to use palynology for analysis of samples from Nova Scotian shell-bearing contexts. (C) 2012 Elsevier Ltd. All rights reserved.