Verrall, C, Stryk, A & Kurukulasuriya, D 2024, 'Hydrochemical and isotopic characterisation of groundwater at an Australian underground mine', in P Andrieux & D Cumming-Potvin (eds), Deep Mining 2024: Proceedings of the 10th International Conference on Deep and High Stress Mining, Australian Centre for Geomechanics, Perth, pp. 1467-1480, https://doi.org/10.36487/ACG_repo/2465_96
(https://papers.acg.uwa.edu.au/p/2465_96_Verrall/)
Abstract: A mine scale water sampling campaign was undertaken at the iron oxide, copper, gold (collectively IOCG) sublevel cave (SLC) asset to ascertain the presence of a possible third, upwelling source of water within the mine and its contribution to inrush hazards. The campaign consisted of 98 water samples testing for δ2H, δ18O and δ13C-dissolved inorganic carbon (DIC) isotopes of which 76 were hydrochemically sampled; testing for potassium, sodium, calcium, magnesium, lithium, bicarbonate, chloride and pH.
The results of this campaign were cross-referenced with historic isotopic water samples (δ2H and δ18O) from the baseline environmental characterisation of the mine site. Through Hydrochemical and isotopic water analysis, water expressions in the mine were classified as belonging to the 2 overlying sedimentary aquifers, 2 previously unknown sources, and 2 mixtures of the newly classified sources.
Using the data from the sampling campaign, historic datasets, and comparison of the fluid fingerprints against waterbodies sourced from the literature; two of the additional water sources were characterised as active hydrothermal systems, both created by radiogenic geothermal heating of evaporated sea water. The results of this paper can be used to categorise any influx of water observed reporting through the drawpoints or intercepted throughout the mine in relation to those that have been characterised in this paper. 

Keywords: isotopic analysis, hydrochemical analysis, underground mine, inrush, sublevel cave