CRUSTAL HELIUM FLUXES AND HEAT-FLOW IN THE GREAT ARTESIAN BASIN, AUSTRALIA

New measurements of the He concentration in bore waters from the Great Artesian Basin (Australia) show: (1) a regional increase in the He-4 flux over the Central Shield, where high heat flow has been attributed to increased U, Th and K in the crust; and (2) a reduced He-4 flux and enhanced He-3 flux in eastern Australia, where high heat flow is attributed to volcanism or underplating during the Cenozoic. These observations suggest correlations between (1) the crustal He-4 flux and the component of heat flow attributed to crustal U and Th (and K), as well as (2) the He-3 flux and recent volcanic activity. However, the specific relations between the heat flux and the He flux can be considerably modified by transport processes and source fractionation. It is suggested that time-dependent tectonic models of heat and mass (He) transport in the crust may be used to constrain either the components of heat flow or the bulk rate of mass transport in the Earth's crust.