86Kr excess and other noble gases identify a billion-year-old radiogenically-enriched groundwater system | Nature Communications

(WARR et al., 2022)

https://www.nature.com/articles/s41467-022-31412-2

Also…

Neon identifies two billion year old fluid component in Kaapvaal craton (LIPPEMANN-PIPKE et al., 2011)

https://www.es.utoronto.ca/wp-content/uploads/2018/11/Lippmann-Pipke-Sherwood-Lollar-et-al-2011-Chemical-Geology.pdf

Websites:

Witwatersrand Basin, South Africa (ClimatePolicyWatchers.org)

https://www.climate-policy-watcher.org/plate-tectonics/witwatersrand-basin.html

Witwatersrand (Strike-Dip.com)

https://strike-dip.com/witwatersrand/