Impure, grey hydromagnesite, up to 60 centimetres thick, and covered with about 30 centimetres of soil, underlies a couple of hectares near the north end of Barnes Lake.

The lake, with an area of 14 to 16 hectares, also contains a sodium carbonate brine to an average depth of 15 centimetres over a large part of the bed. The muddy shoreline and dry portions of the bed are heavily encrusted with dried soda (circa 1937). In the autumn of 1932, a 7-centimetre layer of natron covered a large part of the lake, a sample of which analysed 97.5 per cent Na2CO3, 0.5 per cent NaCl, 0.9 per cent insolubles and 0.7 per cent Fe2O3. Recalculated to a 100 per cent water free basis, the sample as assayed contained 58.9 per cent water of composition (Bulletin 4, page 29).

Several 1.2-metre holes at various points about 4.5 metres from the shore were drilled; no deposit of solid crystals were intersected, but small natron crystals were noted in the mud. Apparently, the muddy bottom contains a fairly high proportion of disseminated crystals and it is reported that a solid layer, 7 to 15 centimetres thick, was intersected at a depth of 1.8 metres (Bulletin 4, page 29).