Mercury in till and bedrock, Kejimkujik National Park, Nova Scotia

摘要

Loons in Kejimkujik National Park have the highest levels of mercury (Hg) concentration in blood of any loon population in North America. For the past several years, a multi-disciplinary team of research scientists has been attempting to identify the potential Hg source(s) and process(es) responsible for the anomalous Hg levels. One component of this research involves the collection and geochemical analysis of till and bedrock samples in order to quantify the geogenic contribution of Hg from glacial sediments and bedrock sources. Health Canada provided funding for the project through the Toxic Substance Research Initiative (TSRI). A total of 39 Chorizon till samples were collected at 100 to 200 m intervals from three NW-SE transects that cross the inferred contact between the Halifax and Goldenville formations immediately south of the park boundary. Samples were collected from depths ranging from 70 to 120 cm. Geochemical results for the < 63 microns size fraction were determined by Cetac CV-AA and indicate Hg ranges from a minimum of 6.6 ppb to a maximum of 158.5 ppb (mean velence 44 ppb).