Stable isotopes as indicators of dissolved methane sources and cycling in the Gippsland Basin, Victoria

Simple item page
dc.contributor.authorCurrell, MJen_AU
dc.contributor.authorCendón, DIen_AU
dc.contributor.authorCartwright, Ien_AU
dc.date.accessioned2021-12-24T00:51:50Zen_AU
dc.date.available2021-12-24T00:51:50Zen_AU
dc.date.issued2017-07-12en_AU
dc.date.statistics2021-11-03en_AU
dc.description.abstractA suite of environmental tracers were analysed from the Gippsland Basin, Victoria, to determine the origins of methane in groundwater and characterise the biogeochemical and physical processes controlling its occurrence and cycling. Water samples were collected from a range of depths and lithology, and were analysed for stable isotopes of methane plus a suite of other tracers - radiocarbon, noble gases (He-4, Ne, Ar), δ18O, δ2H and δ13CDIC. The data were analysed within the hydrogeological framework to characterise sources of methane in groundwater and identify possible transport processes. Methane isotopic compositions ranged widely throughout the system. Two predominant groups of methane were found, both of which were of bacterial origin. One group contained isotopes with typical acetate-fermentation signatures (δ13CCH4 = −45.8 to −66.2‰ and δ2HCH4 = −204 to −311‰), and largely occurred in deep groundwater, near the coast. The other group exhibited unusually depleted δ13CCH4 values by typical global standards (−83.7 to −97.5 ‰) and δ2HCH4 values between −236 and −391‰. This group is associated with relatively shallow groundwater, near areas of extensive lignite. Radiocarbon and He-4 data indicate that groundwater age increases with depth, however inter-aquifer mixing complicates age interpretations. Stable isotopes of water in the deepest parts of the system show relatively depleted δ18O and δ2H, suggesting isotopic modification during methanogenesis and/or depleted signatures associated with palaeo-recharge conditions. The study provides the first data on dual-isotopic compositions of methane in the Gippsland Basin, and new insights into sources and cycling of methane in a multi-layered sedimentary basin. The basin is one in which extensive groundwater extraction and mining activity occurs, which may be having ongoing effects on inter-aquifer connectivity for both water and gases.en_AU
dc.identifier.citationCurrell, M. J., Cendón, D. I., & Cartwright, I. (2017). Stable isotopes as indicators of dissolved methane sources and cycling in the Gippsland Basin, Victoria. Paper presented to the 2017 Biennial Australasian Groundwater Conference, UNSW Sydney, 11 - 13 July 2017. Retrieved from: http://agc-2017.p.agc2017.currinda.com/days/2017-07-12/abstract/40en_AU
dc.identifier.conferenceenddate13 July 2017en_AU
dc.identifier.conferencename2017 Biennial Australasian Groundwater Conferenceen_AU
dc.identifier.conferenceplaceSydney, Australiaen_AU
dc.identifier.conferencestartdate11 July 2017en_AU
dc.identifier.urihttp://agc-2017.p.agc2017.currinda.com/days/2017-07-12/abstract/40en_AU
dc.identifier.urihttps://apo.ansto.gov.au/dspace/handle/10238/12664en_AU
dc.language.isoenen_AU
dc.publisherNational Centre for Groundwater Research And Trainingen_AU
dc.subjectStable isotopesen_AU
dc.subjectMethaneen_AU
dc.subjectSedimentary basinsen_AU
dc.subjectVictoriaen_AU
dc.subjectAustraliaen_AU
dc.subjectTracer techniquesen_AU
dc.subjectWateren_AU
dc.subjectSamplingen_AU
dc.subjectDataen_AU
dc.subjectAquifersen_AU
dc.titleStable isotopes as indicators of dissolved methane sources and cycling in the Gippsland Basin, Victoriaen_AU
dc.typeConference Presentationen_AU
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
GW008_FA Updated.pdf
Size:
4.1 MB
Format:
Adobe Portable Document Format
Description:
Download
License bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
license.txt
Size:
1.63 KB
Format:
Item-specific license agreed upon to submission
Description:
Download
Collections
Conference Publications