Groundwater sources for the Mataranka Springs (Northern Territory, Australia)

Sébastien Lamontagne; Axel Suckow; Christoph Gerber; Alec Deslandes; Cornelia Wilske; Steven Tickell

doi:10.1038/s41598-021-03701-1

Groundwater sources for the Mataranka Springs (Northern Territory, Australia)

Sci Rep. 2021 Dec 20;11(1):24288. doi: 10.1038/s41598-021-03701-1.

Authors

Sébastien Lamontagne¹, Axel Suckow², Christoph Gerber², Alec Deslandes², Cornelia Wilske^{2

3}, Steven Tickell⁴

Affiliations

¹ CSIRO Land and Water, Waite Laboratories, Urrbrae, South Australia, 5064, Australia. sebastien.lamontagne@csiro.au.
² CSIRO Land and Water, Waite Laboratories, Urrbrae, South Australia, 5064, Australia.
³ Faculty of Sciences, School of Physical Sciences, The University of Adelaide, Adelaide, South Australia, 5000, Australia.
⁴ Northern Territory Department of Environment, Parks and Water Security, Palmerston, Northern Territory, 0830, Australia.

Abstract

The Mataranka Springs Complex is the headwater of the iconic Roper River of northern Australia. Using environmental tracers measured in springs and nearby boreholes, the origin of groundwater contributing to the springs was evaluated to help assess the impact of proposed groundwater extraction in the Cambrian Limestone Aquifer (CLA) for irrigation agriculture and for hydraulic fracturing in the Beetaloo Sub-basin (an anticipated world-class unconventional gas reserve). Major ions, Sr, ⁸⁷Sr/⁸⁶Sr, δ¹⁸O-H₂O, δ²H-H₂O, ³H, ¹⁴C-DIC were consistent with regional groundwater from the Daly and Georgina basins of the CLA as the sources of water sustaining the major springs (Rainbow and Bitter) and one of the minor springs (Warloch Pond). However, ³H = 0.34 TU in another minor spring (Fig Tree) indicated an additional contribution from a young (probably local) source. High concentrations of radiogenic ⁴He (> 10^-7 cm³ STP g^-1) at Rainbow Spring, Bitter Spring and in nearby groundwater also indicated an input of deeper, older groundwater. The presence of older groundwater within the CLA demonstrates the need for an appropriate baseline characterisation of the vertical exchange of groundwater in Beetaloo Sub-basin ahead of unconventional gas resource development.

Publication types

Research Support, Non-U.S. Gov't