Bluestone Increases Cerro Blanco Mineral Resource to 3.1 Moz gold and 13.4 Moz silver
VANCOUVER, BC, July 19, 2021 /CNW/ - Bluestone Resources Inc. (TSXV: BSR) (OTCQB: BBSRF) ("Bluestone" or the "Company") is pleased to announce an updated Mineral Resource Estimate for its 100% owned Cerro Blanco gold project located in southern Guatemala. The resource estimate is an update to the resource disclosed in the preliminary economic assessment (see press release 28 February 2021) and will be the basis for the feasibility study currently underway.
Highlights (0.4 g/t Au cut-off)
Jack Lundin, President & CEO, commented, "We are very pleased with this significant upgrade in the mineral resource, which is a culmination of the additional infill drilling completed this year and during the second half of 2020, along with improved understanding and continuous validation of the geology and mineralization. Measured resources have almost doubled from the PEA estimate and now comprise 75 percent of the total ounces, providing a very solid foundation for the open pit reserves calculation and optimized mine plan currently underway as part of the feasibility study. Cerro Blanco is arguably one of the highest grade undeveloped gold projects globally and is in the pipeline as the next big development project for the Lundin Group."
Table 1 – Cerro Blanco Mineral Resource Estimate at a 0.4 g/t Au cut-off
Geology and Mineral Resource
The overlying Salinas unit, a sub-horizontal sequence of volcanogenic sediments and sinter horizons approximately 100 meters thick, form the low-lying hill at the project and is host to low-grade mineralization associated with silicified conglomerates and rhyolite intrusion breccias. This near-surface mineralization and the inverted cone-shape of the underlying high-grade veins render the Cerro Blanco deposit ideally amenable to exploitation by surface methods with a low strip ratio.
The mineral resource has a footprint of 800 x 400 meters between elevations of 525 meters and 200 meters above sea level. The updated estimate is a result of 158,303 meters of surface and underground drilling by Bluestone and previous operators (766 drill holes and 580 channel samples). The mineral resource estimate is based on robust geological and structural models, supported by 3.4 kilometers of underground infrastructure that allowed underground mapping, channel sampling, and 42,207 meters of underground drilling that was critical to Bluestone's current understanding and validation of the Cerro Blanco geological model.
The increase in measured versus indicated resources compared to the previous resource estimate (effective date 31 December 2020) is due not only to additional underground and surface drilling but also improved interpretation and modelling of the lithological units which was imperative for the open pit scenario.
Table 2 – Cerro Blanco Mineral Resource Estimate Sensitivity Analysis (Base Case in bold).
Mineral Resource Estimation Methodology
Mineral Resources are classified under the categories of Measured, Indicated, and Inferred according to CIM guidelines. Mineral Resource classification for gold was based primarily on drill hole spacing and on continuity of mineralization. Measured resources were defined as blocks with a distance to three drill holes of less than ~20 meters to nearest composite and occurring within the estimation domains and Indicated resources were defined as those with a distance to three drill holes of less than ~40 meters. Inferred resources were defined as those with a drill hole spacing of less than ~75 meters and meeting additional requirements.
The deposit was segregated into multiple estimation domains based on geologic models for each of the mineralized veins and the Salinas and Mita host lithologies, including sinter units. The mineral resource was estimated using ordinary kriging interpolation for the continuous vein domains and the Salinas and Mita host units.
Search ellipse anisotropy and orientation were guided by the orientation of the vein solids models and omni-directional ellipsoids were employed in the individual host and sinter zones. Gold and silver block grades were estimated from capped composited samples in a single pass. Final gold and silver grades were calculated by volume weighted averages calculated between percentage within vein and host zones, respectively. A total of 1,308 specific gravity readings were derived from measurements within individual rock types and assigned on a block-by-block basis.
Final resource classification shells were manually constructed on plan sections and all resources are constrained within lithological domains and by the continuous vein solids. Final Resource classification shells were manually constructed on sections. Mined out underground ramp material was extracted from the Measured Resources. Silver was not classified separately and is reported based on gold classification.
These interpreted boundaries were created for the measured, indicated and inferred thresholds in order to exclude orphans and reduce potential "spotted dog" effect.
This estimate is also based upon the reasonable prospect of eventual economic extraction based on an optimized pit, using estimates of reasonable operating costs and price assumptions. The pit optimization results are used solely for testing the "reasonable prospects for eventual economic extraction" and do not represent an attempt to estimate Mineral Reserves.
About Bluestone Resources
On Behalf of Bluestone Resources Inc.
Jack Lundin | President, CEO & Director
Neither the TSX Venture Exchange nor its Regulation Services Provider (as that term is defined in the policies of the
TSX Venture Exchange) accepts responsibility for the adequacy or accuracy of this release.
Forward Looking Statements
All forward-looking statements are made based on Bluestone's current beliefs as well as various assumptions made by Bluestone and information currently available to Bluestone. Generally, these assumptions include, among others: the presence of and continuity of metals at the Cerro Blanco Project at estimated grades; the availability of personnel, machinery, and equipment at estimated prices and within estimated delivery times; currency exchange rates; metals sales prices and exchange rates assumed; appropriate discount rates applied to the cash flows in economic analyses; tax rates and royalty rates applicable to the proposed mining operations; the availability of acceptable financing; the impact of the novel coronavirus (COVID-19); anticipated mining losses and dilution; success in realizing proposed operations; and anticipated timelines for community consultations and the impact of those consultations on the regulatory approval process.
Forward-looking statements are subject to a number of risks and uncertainties that may cause the actual results of Bluestone to differ materially from those discussed in the forward-looking statements and, even if such actual results are realized or substantially realized, there can be no assurance that they will have the expected consequences to, or effects on, Bluestone. Factors that could cause actual results or events to differ materially from current expectations include, among other things: potential changes to the mining method and the current development strategy; risks and uncertainties related to expected production rates; timing and amount of production and total costs of production; risks and uncertainties related to the ability to obtain, amend, or maintain necessary licenses, permits, or surface rights; risks associated with technical difficulties in connection with mining development activities; risks and uncertainties related to the accuracy of mineral resource estimates and estimates of future production, future cash flow, total costs of production, and diminishing quantities or grades of mineral resources; risks associated with geopolitical uncertainty and political and economic instability in Guatemala; risks related to global epidemics or pandemics and other health crises, including the impact of the novel coronavirus (COVID-19); risks and uncertainties related to interruptions in production; the possibility that future exploration, development, or mining results will not be consistent with Bluestone's expectations; uncertain political and economic environments and relationships with local communities and governmental authorities; risks relating to variations in the mineral content within the mineral identified as mineral resources from that predicted; variations in rates of recovery and extraction; developments in world metals markets; and risks related to fluctuations in currency exchange rates. For a further discussion of risks relevant to Bluestone, see "Risk Factors" in the Company's annual information form for the year ended December 31, 2019, available on the Company's SEDAR profile at www.sedar.com.
Any forward-looking statement speaks only as of the date on which it was made, and except as may be required by applicable securities laws, Bluestone disclaims any intent or obligation to update any forward-looking statement, whether as a result of new information, future events or results, or otherwise. Although Bluestone believes that the assumptions inherent in the forward-looking statements are reasonable, forward-looking statements are not guarantees of future performance, and accordingly, undue reliance should not be put on such statements due to their inherent uncertainty. There can be no assurance that forward-looking statements will prove to be accurate, and actual results and future events could differ materially from those anticipated in such statements.
Non-IFRS Financial Performance Measures
All-in sustaining costs
The Company calculates AISC as the sum of refining costs, third party royalties, site operating costs, sustaining capital costs, and closure capital costs all divided by the gold ounces sold to arrive at a per ounce amount. Other companies may calculate this measure differently as a result of differences in underlying principles and policies applied. Differences may also arise due to a different definition of sustaining versus non-sustaining capital.
SOURCE Bluestone Resources Inc.
Company Codes: OTC-QB:BBSRF, TorontoVE:BSR
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