title: Chemical and carbon isotopic composition of dissolved organic carbon in a regional confined methanogenic aquifer.
abstract: This study demonstrates the advantage of a combined use of chemical and isotopic tools to understand the dissolved organic carbon (DOC) cycle in a regional confined methanogenic aquifer. DOC concentration and carbon isotopic data demonstrate that the soil zone is a primary carbon source of groundwater DOC in areas close to recharge zones. An in-situ DOC source linked to organic rich sediments present in the aquifer matrix is controlling the DOC pool in the central part of the groundwater flow system. DOC fractions, 13C-NMR on fulvic acids and 14C data on DOC and CH4 support the hypothesis that the in-situ DOC source is a terrestrial organic matter and discard the Ordovician bedrock as a source of DOC.
authors.affiliation: Department of Earth Sciences University of Waterloo 200 University Ave. W. Waterloo Ontario N2L 3G1 Canada. roaraven@sciborg.uwaterloo.ca
authors.forename: Ramon
authors.initials: R
authors.lastname: Aravena
authors.forename: Leonard I
authors.initials: LI
authors.lastname: Wassenaar
authors.forename: Elliot C
authors.initials: EC
authors.lastname: Spiker
mesh_terms: D002244:Carbon / Q000032:analysis / Q000737:chemistry* / Q000378:metabolism*; D002247:Carbon Isotopes / Q000032:analysis; D004784:Environmental Monitoring; D019015:Geologic Sediments / Q000737:chemistry; D009682:Magnetic Resonance Spectroscopy; D008697:Methane / Q000032:analysis; D009930:Organic Chemicals / Q000378:metabolism; D012987:Soil; D012995:Solubility; D014872:Water Movements; D014881:Water Supply
chemical_list: D002247:Carbon Isotopes; D009930:Organic Chemicals; D012987:Soil; D002244:Carbon; D008697:Methane