Deposit Synonyms

AUSTRALIA SALT CO.; CASTLE SALT; LAKE BUMBUNGA; ML 18; ML 224; ML 54; ML 55; ML 7

Mineral District

Deposit Summary

salt production from saline lake recorded since 1912. Production from 1940-50 ~28,250t per year. Production from 1940-2007 ~745,000t.

Deposit Description

LOCHIEL, or Lochiel Saltfield, salt harvested since 1912. Salt dissolved from surficial saline mud by winter rains fills a 1500Ha inland lake, the largest lake in a district that abounds in small salt lakes. There is an existing salt crust average 20cm thick over an area >3,000 acres, with crust thickness to 60cm on its eastern margin. Early resource estimate was >3,000000 tonne. Though the source of the saline muds has not been ascertained, there appears to be a regular cycle of renewing of the salt resource. Origin of the salt is possibly from aeolian dust rendered saline by contact with sea spray (“Cyclic” salt). There is solution of the salt by rainfall and concentration in the lake by surface drainage then evaporation. Base to the salt is ~1.5m thick of black, gypsiferous mud, and saline mud. When the salinity of the lake waters is appropriate (SG <1.208 at 60F), the waters are pumped into 25Ha crystallizers (areas of the lake with raised banks), located at the southern end of the lake, and the solution left to evaporate to give salt beds to ~7cm thick. In late January to February the salt is mechanically harvested. Production rate from 1940-50 averaged 28,250 tonne per year. Production from 1940-2013 was estimated at 760,000 tonne, with recent production at a few 1,000s tpa. The underlying thickness of salt crust forms a surface suitable for accessing the upper salt resource. Generally it is not worked to any depth, and the surface is maintained on as flat a plane as possible to prevent the appearance of depressions.

Discovery Year

? 1913

Commodities

Salt

Ore Minerals

Halite

Gangue Minerals

?