Radiocarbon in Dissolved Organic Carbon, A Possible Groundwater Dating Method: Case Studies From Western Canada

摘要: This paper explores the feasibility of using 14C in dissolved organic carbon (DOC) as an alternative isotopic ground water dating method. Two hydrogeologically contrasting groundwater systems were tested; Cretaceous age Milk River aquifer, and low-permeability, rich, Wisconsinan Prairie tills southern Alberta, Canada. Comparisons radiocarbon data made between DOC fractions, inorganic (DIC), several DIC geochemical correction models along well defined flow paths. The presented demonstrate that fractions can indeed provide method for determining ages, under suitable conditions. However, detailed information may be required regarding (1) geologic nature aquifer its system, (2) isotopically conservative behavior DOC, (3) initial activity recharge, (4) effect bacterial redox processes on DOC. In ages successfully used to estimate residence times, further refine input parameter assumptions tills, establish a maximum pore waters environment where is especially problematic.