Organic matter content and grain size distribution in a lake sediment core, Bylot Island, Nunavut, Canada.

This dataset presents an estimation of the organic matter content (by loss-on-ignition) and particle size (grain size analysis) in a 109 cm-long lake sediment core from a thermokarst lake in Bylot Island, Nunavut, Canada. The core was collected in June 2015 at « Gull Lake » (also named BYL-66 in other publications) from the still-present ice cover with a 7 cm-diameter percussion corer (Aquatic Research Instruments). First, samples were collected at each cm along the core, then freeze-dried and combusted (550 °C for 4 h) to remove the organic fraction. Second, a part of these samples was grouped into eight stratigraphic sub-units based on visual descriptions of the core. These samples were analyzed for their grain size distribution, either by sieving for coarser material (sand, gravel), or by hydrometry for finer sediment (clay, silt).