Isotopic analyses of 13C and 2H concentrations in methane and determinations of the total gas molecular composition were completed on five samples collected in the Pleistocene sediments of the Trois Rivières area, St-Lawrence Lowlands, and of the Saint-Flavien area, in the Appalachians, where accumulations of natural gas occur. The results indicate that (i) the gas at Yamachiche is biogenic and formed in situ within the Pleistocene deposits, (ii) the gas at Saint-Flavien is thermogenic, and (iii) the gas at Pointe-du-Lac and at the Vieilles-Forges is likely a mixture of both. The petrogenic study of the organic matter of the Beekmantown Group, Middle Ordovician age, suggests that the gas at Saint-Flavien migrated into the present reservoir after the thermal peak. [Journal Translation]

You do not currently have access to this article.