Geological Criteria for the Location of Economi•c Potash Deposits

CIM Bulletin, 1971

M. E. HOLTER, Research Council of Alberta, Edmonton, Alta

Three main potash members are recognized within the Prairie Evaporite Formation of Saskatchewan and have been designated, in ascending order, the Esterhazy, Belle Plaine and Patience Lake members. Each is composed of s ylvinite near the geographic center of the member and becomes increasingly carnallitic marginally. Each stratigraphically higher member has a narrower carnallitic margin. The sharp contact between carnallitic and noncarnallitic components of the formation describes a surface which may be traced regionally and is not related to bedding. The contact rises higher in the stratigraphic section toward margins of members. Within each of the three members, analyses indicate that carnallite becomes more abundant toward the north whereas sylvite and insolubles, increase toward the south. Within each member, areas rich in carnallite are coincident with areas in which the member as a whole is thicker than a verag,e. The Belle Plaine Member contains the highest concentrations of carnallite, the Esterhazy the lowest . A maximum content of about 30 per cent sylvite is common to all three me mbers. Insoluble contents increase in successively higher members. Map studies are combined to outline the economic potential of the potash beds in terms of depth to the top of the Prairie Evaporite, "salt-back" thicknesses and sylvite grades for each member.
Keywords: carnallite, EDGE, Insolubles Sylvite, potash, Prairie Evaporite, Evaporites, formation, Maps, mineral, minerals, mining, potash, Saskatchewan