Summary:
The basis for the Project is the potassium and magnesium mineralization in the three salt members of the Prairie Evaporite Formation; the Patience Lake, Belle Plaine and Esterhazy Members. The stratigraphy of the Prairie Evaporite Formation, the overlying Dawson Bay Formation and underlying Winnipegosis Formation is well documented in the literature.
Potassium mineralization is identified from well data and consists of the Patience Lake, Belle Plaine, and Esterhazy Members.
Patience Lake Member
The Patience Lake Member is stratigraphically the uppermost potash bearing Member of the Prairie Evaporite Formation and within the Property dominantly developed as carnallite (= 40% carnallite). The Member can be subdivided into four sub-members, which are separated by clay rich and barren halite interbeds. The uppermost Patience Lake sub-member is only locally present in the west and usually developed as sylvinite. More commonly, the lower three sub-members of the Patience Lake Member are present as continuous carnallite mineralization. Exception occurs in the southeastern area of the Property near the seismic anomaly, where the second and third sub-member of the Patience Lake is developed as sylvinite. Core indicates that in this well, KW 3B4-16, the original carnallite was transformed to sylvite. The total thickness of the Patience Lake Member over the investigated area of the leases averages 9.4 m in thickness. The depth to the top of the Patience Lake Member occurs around 910 m in the northeast region of the Property and increases to depths around 1,010 m in the southwest. It is thickest in the south; up to 15 m in KW 4B14-24 and thinnest at KW 3B4-26 in the influence zone of a collapse feature.
Mineralization
The Patience Lake Member is typically recognized for its characteristic clay-rich nature, with several laterally extensive clay seams and zones of high insoluble content.
Belle Plaine Member
The Belle Plaine Member occurs stratigraphically below the Patience Lake Member and is predominantly carnallite. It is separated from the Patience Lake Member by an interval of barren halite and clay (interbed). The base of the Belle Plaine is generally marked by a clay seam and a decrease in KCl grade. The depth to the top of the Belle Plaine ranges from 927 m in the northeast to 1,030 m in the south and exhibits a uniform thickness across the Property averaging 15.3 m.
Mineralization
Belle Plaine Member can be divided into a relatively homogeneous Upper Belle Plaine Member (UBPM) consisting of an interlayering of carnallite rich beds with minor halite rich beds and a Lower Belle Plaine Member (LBPM) consisting of an interlayering of halite rich beds with some carnallite and subordinate carnallite rich beds. Towards the bottom of this Member, thin sylvite rich beds usually occur.
The Esterhazy Member
In the Project area, the depth to the top of the Esterhazy ranges from 971 m in the north to 1,074 m in the south. Contrary to the Patience Lake and Belle Plaine Members, the Esterhazy Member is generally sylvinitic within the Project area, with locally appreciable but subordinate amounts of carnallite. The distribution of KCl grade is used for defining the stratigraphy of the Esterhazy (as opposed to the clay seams used in the Belle Plaine and Patience Lake Members). The Esterhazy Member over the Project area has a uniform thickness averaging 16.8 m.
Mineralization
The mineralization is observed to generally occur within two to three distinct higher grade sylvite zones, separated by sylvite bearing rock salt. Based on the average KCl concentration they can be grouped together in one or two mineralized zones that have solution mining potential.
Mapping the Prairie Evaporite Top illustrates that the Prairie Evaporite Formation is flat with a generalized dip of less than 1%. Local variations in dips of greater magnitude may exist, but the very low regional dip is favourable for solution mining with a blanket medium as practiced at Mosaic’s Belle Plaine and K+S Potash Canada potash mines. A series of cross sections for all Karnalyte drilling as well as the reassessed historic drill hole were generated across the Project area. The cross sections illustrate lateral continuity, thickness, and outline the grades of the individual mineral constituents; carnallite and sylvite.
Mineralization
Within the Project area, the typical sylvinitic interval consists of a mass of interlocked sub-hedral to euhedral sylvite crystals that range from reddish orange or pink to translucent in colour. Sylvite may be enveloped by greenish-grey clay or bright red iron oxides, with minor intercrystalline halite disseminated throughout the interval. Local coarse (greater than 2.0– 2.5 cm) cubic translucent to milky white halite crystals may be present within the sylvinite groundmass. Overall, the sylvinite ranges from a dusky brownish red colour (lower grade, 23.0% to 27.0% K2O grade with an increase in amount of insoluble) to a bright, almost translucent pinkish orange colour (high grade, 30.0%+ K2O).
Carnallite consists of aggregated crystal masses of very coarse interlocking amorphous carnallite with minor inclusionary halite and interstitial insoluble. Carnallite commonly exhibits a dark red to bronze colour and may grade locally to shades of very pale pink or may be nearly colourless. Carnallite crystals often display a characteristic variegated colour zoning, plastic texture, and vitreous luster along broken and cut core surfaces. Due to its extremely fragile nature, core preservation during drilling varied within the carnallite intervals ranging from very good to poor and rubbly composition. Intervening barren halite beds between potash members typically consist of brownish red, vitreous to translucent halite with minor sylvite and increased clay content.
The carnallite modelling and interpretation was derived from the original Wynyard 3D seismic study (Tetra Tech, 2010), focused on identifying carnallite responses within the Prairie Evaporite sequence. The analysis involved building models to recreate various lithological scenarios within potash members beneath the Second Red Bed horizon, specifically targeting the Patience Lake, Belle Plaine, and Esterhazy members.
Carnallite Distribution and Solution Mining of Patience Lake and Belle Plaine Members
The mineable carnallite interval within the Patience Lake Member is defined as the upper mineralized seam below the Second Red Bed Member with a thickness over 2 m. From the base of the Second Red Bed Member, the first sample with KCl content over 15% is the top of the mineable carnallite. The mineable bed is defined when the length weighted average with previous and next samples (three to five samples in total about 1 m length) demonstrates a KCl content above 15% and the following average samples below also have an average KCl content above 15%.
Sylvite Distribution and Solution Mining of the Esterhazy Member
The top of the Esterhazy Member (geology interval) is defined at the top of the first sylvinite bed occurring immediately below the “Interbed 2” salt, which separates the Esterhazy from the overlying Belle Plaine Member and is approximately 30 m in thickness. The concentration of sylvite (KCl) is highly variable and ranges from less than 5% to locally over 60% in a sample from 20 cm length.
The Esterhazy Member has been divided into zones that are considered technically and economically suitable for solution mining. This is when the thickness of the productive mineralized zone exceeds 2 m and the average KCl content over the productive horizon exceeds 20%. These parameters are required to obtain from a cavern a significant volume of brine rich enough in KCl to stay within the specifications of the planned process.
Commodity Production
The Wynyard Project has two final commercial products:
• granular potassium chloride (KCl or MOP) as the primary product, and;
• high-purity hydromagnesite as a secondary magnesium product.
A portion of the MgCl2-rich end brine from potash production is used to produce hydromagnesite (a hydrated magnesium carbonate mineral) in a separate facility.
| Commodity | Product | Units | Avg. Annual | LOM |
|
Potash
|
MOP
|
kt
| 2,175 * | 142,202 * |
|
Magnesium
|
Carbonate
|
kt
| 104 * | 7,000 * |
|
KCl
|
|
t
| | 0 * |
* According to 2025 study.