Holle

stratabound potash-bearing salt in Congo

Geologic information

CountryCongo
Location:12.0879, -4.552
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Site typemine
Deposit typestratabound potash-bearing salt
Evaporite basinLower Congo
Basin typemarine rift basin
Geologic unitLoeme Fm
Age
Mesozoic
Cretaceous
Lower Cretaceous
Aptian
Minimum:Mesozoic-Cretaceous-Lower Cretaceous-Aptian
Maximum:Mesozoic-Cretaceous-Lower Cretaceous-Aptian
Commodities
Minerals
Potassium minerals:
Other minerals:
Lithology
Geologic map unit12.0879, -4.552
Nearby scientific dataFind additional scientific data near this location

Economic information

Thickness3-12m
Depth400-700m
Production
StatusPast Production
First year1969
Last year1977
K2O tonnage1) 1.943; 2) 4Million tonnes
Data years1969 to mid-1977
Data source1) de Ruiter (1979); 2) Secretariat... (2006)
Estimates of reserves or resources
Ore tonnagemin: 17 (syl layer 7/8) + 26 (syl layer 3)Million tonnes
K2O tonnagemin: 3.1 (syl layer 7/8) + 9.9 (syl layer 3)Million tonnes
Grade of K2O18 (layer 7/8) to 38 (layer 3)% of ore
Data sourcede Ruiter (1979)

Reference information

Comments

Mine was closed due to flooding in 1977.

References

Ala, M.A., and Selley, R.C., 1997, The west African coastal basins, in Selley, R.C., ed., African basins: New York, Elsevier, p. 173-186.
British Sulphur Corporation Limited, 1979, World survey of potash resources (3d ed.): London, British Sulphur Corporation Limited, 138 p.
de Ruiter, P.A.C., 1979, The Gabon and Congo Basins salt deposits: Economic Geology, v. 74, no. 2, p. 419-431.
Feuga, B., Schlund, J.-M., and Wasmer, B., 2005, The flooding of the Holle potash mine (Republic of Congo), in Fall 2005 Conference, October 2-5, 2005, Nancy, France: Clarks Summit, Penn., Solution Mining Research Institute, 19 p.
Garrett, D.E., 1996, Potash; Deposits, processing, properties and uses: New York, Chapman and Hall, 734 p.
Secretariat of the African, Caribbean and Pacific Group of States (SACPGS), 2006, Mining data bank: Secretariat of the African, Caribbean and Pacific Group of States Web page accessed April 3, 2006, at http://mines.acp.int/html/mine_COG-00024_en.html.
Warren, J., 1999, Evaporites; Their evolution and economics: Malden, Mass., Blackwell Science, 438 p.
Williams-Stroud, S.C., Searls, J.P., and Hite, R.J., 1994, Potash resources, in Carr, D.D., ed., Industrial minerals and rocks: Littleton, Colo., Society for Mining, Metallurgy and Exploration, p. 783-802.