Biogeochemical constraints on the origin of methane in an alluvial aquifer: evidence for the upward migration of methane from underlying coal measures

Simple item page
dc.contributor.authorIverach, CPen_AU
dc.contributor.authorBeckmann, Sen_AU
dc.contributor.authorCendón, DIen_AU
dc.contributor.authorManefield, Men_AU
dc.contributor.authorKelly, BFJen_AU
dc.date.accessioned2022-01-25T00:56:04Zen_AU
dc.date.available2022-01-25T00:56:04Zen_AU
dc.date.issued2017-04-26en_AU
dc.date.statistics2022-01-10en_AU
dc.description.abstractGeochemical and microbiological indicators of methane (CH4) production, oxidation and migration processes in groundwater are important to understand when attributing sources of gas. The processes controlling the natural occurrence of CH4 in groundwater must be characterised, especially when considering the potential impacts of the global expansion of unconventional gas production on groundwater quality and quantity. We use geochemical and microbiological data, along with measurements of CH4 isotopic composition ( 13C-CH4), to determine the processes acting upon CH4 in a freshwater alluvial aquifer that directly overlies coal measures targeted for unconventional gas production in Australia. A combination of geochemical and microbiological groundwater samples were collected from private irrigation boreholes. The groundwater was analysed for the major ions, water stable isotopes ( 2H and 18O), the isotopic composition of dissolved organic carbon ( 13CDOC) and dissolved inorganic carbon ( 13CDIC). Quantitative realtime PCR was used to determine abundances of bacterial and archaeal 16S rRNA gene targets and functional gene targets in the groundwater. Measurements of CH4 indicate that there is biogenic CH4 in the aquifer, however microbial community analysis indicates that there are no methanogenic archaea in the groundwater. In addition, geochemical data, particularly the isotopes of DIC and, as well as the concentration of SO2-4 , indicate limited potential for methanogenesis insitu. Microbial community analysis also showed that aerobic oxidation of CH4 is occurring in the alluvial aquifer despite the absence of a microbial pathway to produce the CH4. The combination of microbiological and geochemical indicators suggests that the most likely source of CH4, where it was present in the freshwater aquifer, is the upward migration of CH4 from the underlying coal measures. © Author(s) 2016. CC Attribution 3.0 License.en_AU
dc.identifier.citationIverach, C. P., Beckmann, S., Cendón, D. I., Manefield, M., & Kelly, B. F. J. (2017). Biogeochemical constraints on the origin of methane in an alluvial aquifer: evidence for the upward migration of methane from underlying coal measures. Oral presentation to the European Geoscience Union General Assembly 2017, Vienna, Austria, 23-28 April 2017. Retrieved from: https://meetingorganizer.copernicus.org/EGU2017/EGU2017-34.pdfen_AU
dc.identifier.conferenceenddate28 April 2017en_AU
dc.identifier.conferencenameEuropean Geoscience Union General Assembly 2017en_AU
dc.identifier.conferenceplaceVienna, Austriaen_AU
dc.identifier.conferencestartdate23 April 2017en_AU
dc.identifier.otherEGU2017-34en_AU
dc.identifier.otherOrals BG1.2en_AU
dc.identifier.urihttps://meetingorganizer.copernicus.org/EGU2017/EGU2017-34.pdfen_AU
dc.identifier.urihttps://apo.ansto.gov.au/dspace/handle/10238/12718en_AU
dc.language.isoenen_AU
dc.publisherEuropean Geosciences Unionen_AU
dc.subjectAquifersen_AU
dc.subjectCoalen_AU
dc.subjectGeochemistryen_AU
dc.subjectCarbon 14en_AU
dc.subjectGround wateren_AU
dc.subjectAustraliaen_AU
dc.subjectDataen_AU
dc.subjectMiningen_AU
dc.subjectFresh wateren_AU
dc.titleBiogeochemical constraints on the origin of methane in an alluvial aquifer: evidence for the upward migration of methane from underlying coal measuresen_AU
dc.typeConference Abstracten_AU
Files
Original bundle
Now showing 1 - 1 of 1
Thumbnail Image
Name:
EGU2017-34.pdf
Size:
52.5 KB
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