Polygon Pond evaporite occurrence, Kamloops Mining Division, British Columbia, Canadai

Regional Level Types
Polygon Pond evaporite occurrence	Pond
Kamloops Mining Division	Division
British Columbia	Province
Canada	Country

The Polygon Pond evaporite occurrence is located just south of the Trans-Canada Highway (Canada Highway No. 1), immediately west of its junction with the Coquihalla Highway (British Columbia Highway No. 5), within the city limits of Kamloops, British Columbia, in the Kamloops Mining Division.
There is a brief description of the geological setting for this occurrence on the British Columbia “Minfile” site, current to 2003, as quoted below:
“Lake No. 4 or Polygon Lake [sic], about 1.8 hectares in area, lies 1000 metres west-northwest of Ironmask Lake (092INE073) in the same general depression, although its surface is 9 to 12 metres lower. The divide between the two is only about 3 metres above the surface of Ironmask Lake. Diorite of the Cherry Creek unit of the Late Triassic-Early Jurassic Iron Mask batholith outcrops along the south shore. . . .”
“The lake is roughly circular and the shorelines steep. In October 1937, at least 1.5 metres of brine was present. The shoreline was encrusted with dried salts but no permanent crystals were noted. A sample of the brine analysed total solids 11.67 per cent with a specific gravity of 1.1075 at 16 degrees Celsius. The composition of the solids were 32.8 per cent Na2SO4, 62.0 per cent MgSO4, 1.6 per cent NaCl, 1.4 per cent Na2CO3 and 2.1 per cent CaSO4. The similarity of the brine to that of Ironmask Lake is notable. When examined, the lake would have contained 635 tonnes of mixed salts per 0.3 metre depth, or a total probably in excess of 2721 tonnes (Bulletin 4) [Cummings, 1940]. The sodium sulphate mineral assumed to be present is mirabilite and the magnesium sulphate mineral, epsomite.”
Giles Peatfield comments:There are a number of evaporite ponds in the general Kamloops area, with slightly differing characteristics. I have chosen Polygon Pond to report on, as it has rather more mineralogical information than others in the area.
Comment on Minerals Reported:
The minerals listed were all reported by Renaut and Stead (1994), based on “preliminary X-ray analysis” – it is not known if this work was followed up.
Comment on Rock types Reported:
Mapping by Kwong (1987) shows that Polygon Pond is located within the area of the Cherry Creek phase of the Upper Triassic to Lower Jurassic Iron Mask Batholith.

Other Databases

Link to British Columbia Minfile:	092INE074

Other Regions, Features and Areas containing this locality

References