Total mercury, methylmercury, nitrogen, carbon, hydrogen, and sulfur concentrations in a degrading lithalsa field near Kangiqsualujjuaq (Nunavik, Canada)

This dataset contains the data used for the scientific article " Methylmercury concentrations in a degrading lithalsa field: effects of thermokarst development and revegetation", submitted to Science of the Total Environment (Cardinal et al., 2025, submitted).

Samples were collected in September 2022 from a degrading lithalsa field at the margin of Tasialuk Lake, Kangiqsualujjuaq, Nunavik, Canada. The dataset includes analyses of soil total mercury (THg), methylmercury (MeHg), nitrogen (N), carbon (C), hydrogen (H), sulfur (S), loss on ignition, grain size distribution, and key environmental variables associated with the soil samples. Additionally, surface water samples from thermokarst ponds were analyzed for filtered and unfiltered THg and MeHg.

Soil samples were collected at depths of 10, 20 and 30 cm from different geomorphic units, including degrading lithalsas, rim ridges, and thermokarst ponds at various stages of revegetation. Vertical profiles were also collected from a lithalsa (390 cm deep, with permafrost from 115–390 cm), a revegetated thermokarst pond (60 cm deep), and a rim ridge (90 cm deep). Recorded environmental parameters include water table depth, thaw depth, wetness, and organic matter thickness.