New lakes are usually formed in thermokarst trough caused by permafrost thawing. Weathering phenomena associated with permafrost thawing results in a very turbid environment. Since appearance of those lakes is spreading to the north and their physico-chemical parameters and their consequences on the territory remains poorly known, my essay, among other studies, studies one of these lakes. It is the BGR-A lake, part of the BGR study site, situated approximately 20 km east-north-east from Umiujaq. The main goal is to study the sedimentological and limnological of the BGR-A lake and to elaborate a model that could interpret its sedimentary dynamic. More specifically, to analyse sediment samples recovered on the field, to associate sedimentological data to limnological conditions measured by another team on the field, to establish a correlation between sedimentation rate and local meteorological conditions and to put all data in a sediment dynamics model. Methodology includes sediment traps set in the lake for two years, a sediment core took near the lake and a sample of the lake bottom. The analyses are the C-H-N composition, loss on ignition, particle size and 14C datation for a peat sample. Limnological and meteorological data will be associated to these results.