Learning Objectives

Notes

22.1
To identify the physical and chemical characteristics of potash and examine potash ore.

Students could begin the unit with a class discussion about potash, to assess what students already know about this mineral. Saskatchewan has one of the world’s largest deposits of potash. At current levels of consumption, the province could fulfill the world’s demand for fertilizer for the next several hundred years.

Students could study unrefined ore samples and record their observations as to colour, taste (with appropriate precautions), size and shape of crystals, hardness, solubility of lump and crushed forms, etc.

Students could conduct research to discover the chemical formulae and chemical characteristics of potash and become familiar with the different potash ores.

Students could begin a glossary of potash-related terms.

22.2
To describe the significance of the Devonian period in the formation of Western Canada’s mineral resources and identify commercial minerals, in addition to potash, that formed during the Devonian period.

Students should examine in detail the geological changes that occurred in Saskatchewan during the Devonian period -- including the significance of the Elk Point Sea in the formation of potash. Students should become familiar with terms such as precipitate, halite, carnallite, prairie formation, evaporite and mineral salts.

Simple evaporation experiments using table salt, potash samples, water and heat illustrate how sedimentation of potash and other minerals could occur. Particularly if normal evaporation processes are used (perhaps assisted by a classroom radiator), students using a hand lens or microscope could examine and draw, photograph, or video the crystal structure of the evaporites.

Students could research the formation of clays such as bentonite, as well as sodium phosphate.

22.3
To explain how potash was used historically.

Students could investigate how the name “potash” originated, where and when potash was first used and the historical uses of potash.

22.4
To describe the location of Saskatchewan potash.

Students could study geological maps to determine the extent of the Prairie Evaporite deposit. The depth and thickness of the deposit are important factors to consider when determining the mining techniques required. Students should compare this deposit to other deposits worldwide.

22.5
To describe how potash was discovered in Saskatchewan.

Rocanville was the site of the first discovery. Students could research methods of exploration for potash and how geologists determine the location of a potential deposit. Potash samples and possibly core samples may be obtained from most potash mines free of charge.

22.6
To explain why mining companies conduct feasibility studies and environmental impact assessments.

Students should understand the meaning of these terms and the significance of the results to the mining companies. They should find out why the studies are done, who does the studies, who pays and what happens to the results.

22.7
To compare the three main potash beds being mined in the province and to map the locations of the operating mines.

Students could explore the differences between the Patience Lake formation, the Belle Plaine formation and the Esterhazy formation. Charts showing the depth, extent and shape of the formations would simplify the explanations and help understand the type of mining used. If they have not already done so in Module 1, students could plot the locations of the present mines on a map that shows the extent of the potash field in Saskatchewan.