Groundwater surveys in uranium-mineralised areas

Helium contents of groundwaters in mineralised locations and (in italics) in neighbouring unmineralised areas 

Country Location (reference) Depth, m - Sample -Type No. He (pL/L) Range Mean  

Sample types (a) holes intersecting mineralisation (b) mineralised interval (c) probably mineralised interval (d) samples equivalent to those associated with mineralisation (d , from structural zones) (e) stock wells and bores (f) deep bores. 

Clarke and Kugler (1973) reported excesses of He in the one hole sampled near the Nordic mine at Elliott Lake, Ontario (1.56-8.69 pL/L He), and in several holes in a potential ore body in Labrador (0.05-28 pL/L He). Similar results were reported by Dyck et al. (1977) from Key Lake, Saskatchewan, where up to 20 pL/L He occurred in deep holes (60-100 m) intersecting mineralisation. Both studies showed that, in many holes. He contents increased with depth, presumably due to upward degassing and equilibrium with the atmosphere. Groundwaters away from mineralisation at Key Lake contained less than 0.043 pL/L He, suggesting that high values in the U deposits were due to the mineralisation itself, but the data are too few to be conclusive. 

Earle and Drever (1983) found He concentrations of 0.05-236 pL/L in groundwaters from various depths (up to 500 m) in the Athabasca Basin, Saskatchewan. They claimed there to be a moderate correlation between the occurrence of He anomalies and known U mineralisation, provided the He concentrations were divided by sample salinity in a rough correction for groundwater residence time. 

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