Stina Re-Submits Technical Report on Bisoni-McKay Vanadium Property
September 13, 2016
As a result of a review by the British Columbia Securities Commission, we are issuing the following news release to clarify our disclosure.
Further to the news release dated March 1, 2016 Stina Resources Ltd. (the “Company”) announces that it has re-submitted a NI 43-101 technical report on the Company’s Bisoni McKay vanadium property in North-Central Nevada dated October 23, 2015, amended August 29, 2016 (the “Amended Technical Report”).
The previously filed technical report regarding the Company’s Bisoni McKay vanadium property dated October 23, 2015 (the “Previous Technical Report”) had numerous deficiencies with respect to NI 43-101 compliance, some of which are as follows:
1) the Previous Technical Report was not organized according to the headings prescribed in the Form 43-101F1;
2) the Previous Technical Report contained calculation, reference, and presentation errors;
3) the author’s certifications included in the Previous Technical Report did not meet current NI 43-101 standards; and the mineral resource estimates in
The Previous Technical Report did not reference May 2014 CIM standards, and did not properly support its stated cut-off grades with respect to these resource estimates. The Previous Technical Report has now been updated to reflect the corrections and restructuring including clarifying that the resource estimate on the Bisoni McKay vanadium property has been reduced from 0.3%, as used in the January 20, 2008 report, to a 0.2% cutoff grade in this report, as per 2014 CIM Definition Standards regarding the “reasonable prospects of eventual economic extraction”.
In the April 2, 2012 news release the cut-off grades were set at 0.3% and 0.2% V2O5 for the lower limits of the bulk tonnage mining grade that were considered sufficiently conservative and economically realistic for mining at BMK property. The 0.3% grade was considered highly anomalous. Grades less than 0.3% to 0.1% would be considered as weakly mineralized and would fall into the class of contained mineral content. As such, the latter would be weakly anomalous rock. The revised cutoff value declared in May 2014 was lowered to 0.2% V2O5, and only the grades less than 0.2% to 0.1% now being considered weakly anomalous within the class of contained mineral. Any rock containing grades of 0.2% and above is considered highly anomalous.
Lowering the cutoff grade to 0.2% was prompted by several factors. The BMK deposit is a stratabound, syngenetic deposit. Vanadium collected in the shale sediments as it was deposited. The low-grade transition at the bottom of the reduced vanadium mineralization comes to an abrupt end as the collection mechanism for vanadium ceased because changes in the sedimentary environment. The decline in V2O5 grade is tied to a few shale beds at the bottom of the mineralized zone. The change from mineralization to low-grade or non-mineralized material is usually an abrupt transition, and when mineralization values drop below 0.2% V2O5, succeeding grades will quickly decline within 5 to 10 feet into a section of low-grade rock with grades usually ranging from 0.02% to 0.08%. The 0.2% grade is a natural grade cut-off at the bottom of the mineralized zone. It is a good sign that the bottom strata carrying higher-grade mineralization has been reached, and it will be a fairly reliable signal for the geologist and the future pit mine staff not to expect further mineralization below. If there are any short pulses a few feet thick of higher V2O5 grades, they will remain below 0.2% at high background levels in the category of contained mineral content. Using a cutoff of 0.3% would often leave some 0.2% mineralization behind that would be of interest.
Furthermore, at the nearby Gibellini Vanadium Prospect, the NI 43-101 Technical Report on Feasibility Study dated August 31, 2011 uses cutoffs of 0.07% and 0.08% for the two mineralized bodies on the site. The Gibellini mineralization is interpreted to be very similar to Bisoni McKay, and the cutoff levels used in the amended report are higher than those used in the Gibillini report.
There has been no change in the resource estimate tonnage measurement at both the 0.3% and 0.2% cutoff levels. In addition to updating to the resource estimate and the report update, the Company inspected survey control on the property, inspected samples in storage in Eureka, NV, and took some additional field samples for later testing. Phase II is now complete.
The Amended Technical Report was authored by Ed Ullmer, P. Geo - AIPG, MSc and BSc. and Edwin H. Bentzen III, BSc. and SME Registered Member and is available at www.sedar.com and on the Company website.
The disclosure of the technical information contained in this news release has been reviewed and approved by Edwin Ullmer, P. Geo - AIPG, BSc, MSc., geologic consultant for the Company and a qualified person as defined under NI 43-101.