Palaeohydrogeology and transport parameters derived from 4He and Cl profiles in aquitard pore waters in a large multilayer aquifer system, central Australia

Stacey Priestley, Tavis Kleinig, Andrew Love, Vincent Post, Paul Shand, Martin Stute, Ilka Wallis, Daniel Wohling

    Research output: Contribution to journalArticlepeer-review

    4 Citations (Scopus)

    Abstract

    A study of chloride and 4He profiles through an aquitard that separates the Great Artesian Basin from the underlying Arckaringa Basin in central Australia is presented. The aquitard separates two aquifers with long water residence times, due to low recharge rates in the arid climate. One-dimensional solute transport models were used to determine the advective flux of groundwater across the aquitard as well as establish any major changes in past hydrological conditions recorded by variations of the pore water composition. This in situ study showed that both diffusion and slow downward advection (vz=0.7 mm/yr) control solute transport. Numerical simulations show that an increase in chloride concentration in the upper part of the profile is due to a reduction in recharge in the upper aquifer for at least 3000 years. Groundwater extraction since 2008 has likely increased chloride and 4He concentrations in the lower aquifer by pulling up water from deeper layers; however, there has been insufficient time for upward solute transport into the pore water profile by diffusion against downward advection. The transport model of 4He and chloride provides insight into how the two aquifers interact through the aquitard and how climate change is being recorded in the aquitard profile.

    Original languageEnglish
    Article number9839861
    Number of pages17
    JournalGEOFLUIDS
    Volume2017
    DOIs
    Publication statusPublished - 2017

    Fingerprint Dive into the research topics of 'Palaeohydrogeology and transport parameters derived from 4He and Cl profiles in aquitard pore waters in a large multilayer aquifer system, central Australia'. Together they form a unique fingerprint.

    Cite this