Summary:
Phosphate and vanadium-rich mineralized beds within the Paris Hills Phosphate Project (the Property) are hosted in the Meade Peak Member of the Permian Phosphoria Formation. The Phosphoria Formation is folded into the Paris Syncline, a north-plunging asymmetrical syncline with a gently dipping to horizontal eastern limb and a steeply dipping to overturned western limb. The mineralized beds dip north-northwest between 7 degrees (°) and 22° along the northplunging horizontal limb of the syncline. The horizontal limb contains the principal resource target with additional mineralization contained in the steeply dipping, upturned limb of the syncline.
The target phosphate mineralization is contained in two zones (beds) within the Meade Peak Member, the Upper Phosphate Zone (UPZ) and Lower Phosphate Zone (LPZ), which range in depth from outcrop to more than 1,000 meters (m) deep. Vanadium is contained in a zone located immediately below the UPZ. Mineralization in the upturned limb has a strike length of over 3 km on the Property.
Mineralization.
At PHA ( Paris Hills Agricom), three stratiform-bedded zones within the Meade Peak Member of the Phosphoria Formation are of potential economic interest. These are, from top to bottom:
- Upper Phosphate Zone (UPZ) occurs approximately 3 m below the contact with the Rex Chert Member. Based on historical evaluation of outcrops, trenches, underground workings and drill penetrations, this bed averages about 4.6 m thick and averages between 21 percent (%) and 25% phosphorus pentoxide (P2O5). The UPZ is regionally called the “D” bed and consists of interbedded pelletal and argillitic material with a relatively sharp lower contact grading upward to higher grade coarse pelletal and pisolitic phosphorite and mudstones (Hale 1967).
- Vanadium Zone (VZ) occurs as three beds, lies immediately below the UPZ, and is designated the “D1” bed. Based on historical reports, it averages between 3.4 and 3.8 m thick with an average vanadium pentoxide (V2O5) grade of 0.74% to 0.92%. The VZ includes three lithologic types with different vanadium grades.
- Lower Phosphate Zone (LPZ) occurs about 1.5 m above the Meade Peak Member’s contact with the underlying Wells Formation and approximately 50 m below the VZ. Regionally called the “A” bed, it is a high-grade pelletal phosphorite overlying a basal mudstone and phosphoric fish- scale marker bed (Hale 1967). This bed ranges from 1.1 to 2.9 m thick and averages an overall grade of about 25.0% P2O5. Resource grades were subject to a cutoff of greater than or equal to 24%, resulting in much higher average grade.
In addition to the three beds described above, there are significant intervals located between the VZ and the LPZ, ranging from 3 to 15 m thick, and averaging from 10% to 15% P2O5.
The mineralized beds described above occur in both the upturned limb and the horizontal limb of the Paris Syncline. Grades and thicknesses in both the upturned limb and the horizontal limb of the anticline are similar, although improvement in grade is noted in areas where the phosphorite has been weathered and/or alteration. This is largely due to driving off contaminants such as calcium carbonate in the weathering process, thereby concentrating the grade. That process may be by chemical or mechanical means and may occur due to areal and sub-areal exposure and faulting.
Mineralization in the upturned limb has a strike length of over 3.2 km and extends from the surface to a depth exceeding 1,000 m, depending on the location of outcrops along the northtrending strike. Depths of the horizontal limb range from surface along the north side of Bloomington Canyon to estimated depths of 915 to 1,035 m at Paris Canyon.