title: Exploring222Rn as a tool for tracing groundwater inflows from eskers and moraines into slope peatlands of the Amos region of Quebec, Canada.
abstract: Peatlands can play an important role in the hydrological dynamics of a watershed. However, interactions between groundwater and peat water remain poorly understood. Here, we present results of an exploratory study destined to test radon (222Rn) as a potential tracer of groundwater inflows from fluvioglacial landform aquifers to slope peatlands in the Amos region of Quebec, Canada.222Rn occurs in groundwater but is expected to be absent from peat water because of its rapid degassing to the atmosphere. Any222Rn activity detected in peat water should therefore derive from groundwater inflow.222Rn activity was measured in groundwater from municipal, domestic wells and newly drilled and instrumented piezometers from the Saint-Mathieu-Berry and Barraute eskers (n = 9), from the Harricana Moraine (n = 4), and from the fractured bedrock (n = 3). Forty measurements of222Rn activity were made from piezometers installed in five slope peatlands, along six transects oriented perpendicular to the fluvioglacial deposits. The relationship between222Rn and total dissolved solids (TDS) measured in water from the mineral deposits underlying the peat layer suggests that222Rn is introduced by lateral inflow from eskers and moraine together with salinity. This input is then diluted by peat water, depleted in both TDS and222Rn. The fact that a relationship between TDS and222Rn is visible calls for a continuous inflow of groundwater from lateral eskers/moraines, being222Rn rapidly removed from the system by radioactive decay. Although more research is required to improve the sampling and tracing techniques, this work shows the potential of222Rn tracer to identify groundwater inflow areas from granular aquifers found in eskers and moraines to slope peatlands.
authors.affiliation: GEOTOP and Département des Sciences de la Terre et de l'atmosphère, Université du Québec à Montréal, C.P. 8888, Succ. Centre-Ville, Montréal, QC H3C 3P8, Canada.
authors.forename: Laureline
authors.initials: L
authors.lastname: Berthot
authors.affiliation: GEOTOP and Département des Sciences de la Terre et de l'atmosphère, Université du Québec à Montréal, C.P. 8888, Succ. Centre-Ville, Montréal, QC H3C 3P8, Canada. Electronic address: pinti.daniele@uqam.ca.
authors.forename: Daniele L
authors.initials: DL
authors.lastname: Pinti
authors.affiliation: GEOTOP and Département des Sciences de la Terre et de l'atmosphère, Université du Québec à Montréal, C.P. 8888, Succ. Centre-Ville, Montréal, QC H3C 3P8, Canada.
authors.forename: Marie
authors.initials: M
authors.lastname: Larocque
authors.affiliation: GEOTOP and Département des Sciences de la Terre et de l'atmosphère, Université du Québec à Montréal, C.P. 8888, Succ. Centre-Ville, Montréal, QC H3C 3P8, Canada.
authors.forename: Sylvain
authors.initials: S
authors.lastname: Gagné
authors.affiliation: GEOTOP and Département des Sciences de la Terre et de l'atmosphère, Université du Québec à Montréal, C.P. 8888, Succ. Centre-Ville, Montréal, QC H3C 3P8, Canada.
authors.forename: Miryane
authors.initials: M
authors.lastname: Ferlatte
authors.affiliation: Groundwater Research Group, Research Institute on Mines and the Environment, Université du Québec en Abitibi-Témiscamingue, Campus d'Amos, 341, rue Principale Nord, Suite 5004, Amos, QC J9T 2L8, Canada.
authors.forename: Vincent
authors.initials: V
authors.lastname: Cloutier
mesh_terms: D060587:Groundwater / Q000737:chemistry*; D011792:Quebec; D011834:Radiation Monitoring; D011886:Radon / Q000032:analysis*; D012987:Soil; D014875:Water Pollutants, Radioactive / Q000032:analysis*; D060986:Water Wells
chemical_list: D012987:Soil; D014875:Water Pollutants, Radioactive; D011886:Radon
keywords: (222)Rn; Esker; Groundwater discharge; Moraine; Peatland; Québec