3.2 Million Ounces Measured and Indicated Resource Averaging 10.5 g/t Au
3.6 Million Ounces Inferred Resource Averaging 8.6 g/t Au
This MRE reflects the results of approximately 1.7 million metres of drilling, with 1.5 million metres completed by Osisko since
An additional 70,000 metres of infill and expansion drilling has been completed since
HIGHLIGHTS
- 3.2 M oz measured & indicated ("M&I") resource avg. 10.5 g/t Au
- M&I resource increase of 73% with avg. grade increased by 14%
- Lynx contains 60% of MRE total gold
- Lynx resource: M&I 2.3 M oz avg. 12g/t Au; Inferred 1.8 M oz avg. 10.9 g/t Au
- 3.6 M oz inferred resource avg. 8.6 g/t Au, reflecting a grade increase of 8%
- 50% of the MRE is hosted in 30 wireframes
- 98% of MRE is located from surface to 1200 m vertical depth
- Exploration ramp access currently at >600 m vertical depth in Lynx
- Lynx 600 bulk sample (Triple Lynx at level 600) work in progress; prior Lynx 311 bulk sample returned 189% positive grade reconciliation (see Osisko news release dated
December 11, 2019 ) - Strong open potential for expansion of high-grade zones in Lynx to the East and down plunge
Chief Executive Officer of Osisko John Burzynski commented: "The world-class Windfall deposit continues to impress with grade and scale. Infill drilling has again exceeded our expectations, with excellent conversion, and the M&I resource increasing by 73% with average gold grade moving past double digits to 10.5 g/t. This MRE forms a strong foundation for the upcoming feasibility study. We are confident that as we complete the remaining infill work in the coming months, the resource will continue to grow and we should again see incremental increase in what is already a strong average grade."
The MRE sensitivity table (Table 1) shows the potential for additional resources through optimizing costs and cut-off grade which will be reviewed during feasibility work. Table 2 shows resources by main area of the Windfall deposit.
Table 1: Windfall Gold Deposit Mineral Resource Estimate Sensitivity Table(1)
Cut-off (g/t Gold) | Measured + Indicated | Inferred | ||||||||
Tonnes (000 t) | Gold (g/t) | Ag (g/t) | Gold (000 oz) | Ag (000 oz) | Tonnes (000 t) | Gold (g/t) | Ag (g/t) | Gold (000 oz) | Ag (000 oz) | |
5.0 | 6,904 | 12.9 | 6.0 | 2,859 | 1,336 | 8,568 | 10.8 | 6.0 | 2,986 | 1,648 |
4.5 | 7,635 | 12.1 | 5.7 | 2,971 | 1,406 | 9,709 | 10.1 | 5.6 | 3,160 | 1,734 |
4.0 | 8,472 | 11.3 | 5.4 | 3,084 | 1,483 | 11,241 | 9.3 | 5.1 | 3,369 | 1,849 |
3.5 | 9,472 | 10.5 | 5.2 | 3,204 | 1,570 | 13,035 | 8.6 | 4.7 | 3,585 | 1,984 |
3.0 | 10,680 | 9.7 | 4.8 | 3,330 | 1,662 | 15,282 | 7.8 | 4.3 | 3,819 | 2,132 |
2.5 | 12,127 | 8.9 | 4.5 | 3,456 | 1,766 | 18,554 | 6.9 | 3.9 | 4,108 | 2,327 |
Note: (1) MRE cut-off of 3.5 g/t Au.
Table 2: Windfall Gold Deposit Mineral Resource Estimate by Area (3.5 g/t Au cut-off)
Area | Measured | Indicated | Inferred | |||||||||||||
Tonnes(1) (000 t) | Gold (g/t) | Ag (g/t) | Gold(1) (000 oz) | Ag(1) (000 oz) | Tonnes(1) (000 t) | Gold (g/t) | Ag (g/t) | Gold(1) (000 oz) | Ag(1) (000 oz) | Tonnes(1) (000 t) | Gold (g/t) | Ag (g/t) | Gold(1) (000 oz) | Ag(1) (000 oz) | ||
Lynx(2) | 565 | 11.6 | 7.2 | 210 | 131 | 5,430 | 12.0 | 5.4 | 2,096 | 944 | 5,052 | 10.9 | 7.1 | 1,777 | 1,147 | |
Underdog | - | - | - | - | - | 800 | 9.5 | 3.3 | 244 | 85 | 4,419 | 7.9 | 3.0 | 1,119 | 432 | |
Main(3) | - | - | - | - | - | 2,676 | 7.6 | 4.8 | 654 | 410 | 2,909 | 5.8 | 3.3 | 540 | 306 | |
Triple 8 | - | - | - | - | - | - | - | - | - | - | 655 | 7.1 | 4.7 | 149 | 99 | |
Total | 565 | 11.6 | 7.2 | 210 | 131 | 8,907 | 10.5 | 5.0 | 2,994 | 1,439 | 13,035 | 8.6 | 4.7 | 3,585 | 1,984 |
Notes: (1) Values are rounded to nearest thousand which may cause apparent discrepancies. (2) Lynx area includes:
This MRE reflects the results of 4,536 drill holes (1,722,097 metres of core) in the resource area, including 3,882 drill holes (1,539,984 metres of core) completed by Osisko from
This mineral resource estimate reflects the current status of the geological interpretation supported by infill drilling, underground mapping and bulk sample results. Most mineralized envelopes in the Main area are associated with pyritic stringers. Lynx and Underdog mineralized lenses predominantly form an extensive anastomosed network of quartz-rich and pyrite-rich veins. The mineralization system is located near contacts between volcanic and pre-mineral intrusive rocks in Main and Lynx areas, and more specifically, within pre-mineral intrusive units in Underdog.
The MRE is 50% contained within 30 wireframes, and 75% contained within 98 wireframes. The MRE considers a total of 556 mineralized lenses defined by individual wireframes with a minimum true thickness of 2.0 metres. The MRE reports grade blocks inside volumes potentially mineable by underground methods at a cut-off grade of 3.5 g/t Au. The cut-off calculation below has been rounded up to 3.5 g/t Au to better represent a future mining cut-off (Table 3).
Table 3: Parameters used to estimate the underground cut-off grade
for the Windfall Gold Deposit Mineral Resource Estimation
Parameters | Unit | Value |
Gold Price | USD/oz | 1,600 |
Exchange Rate | USD/CAD | 1.26 |
Mill Recovery | % | 94.9 |
Payability | % | 99.95 |
Sell Cost | USD/oz | 5 |
Royalties (NSR) | % | 2 |
CAD/t milled | 107 | |
G&A Cost | CAD/t milled | 32 |
Processing Cost | CAD/t milled | 31 |
Transportation | CAD/t milled | 2 |
Environment | CAD/t milled | 12 |
Calculated Cut-off Grade | g/t Au | 3.1 |
MRE Cut-off Grade | g/t Au | 3.5 |
Windfall Gold Deposit Mineral Resource Estimate Notes
1. The independent qualified person for the MRE, as defined by NI 43-101 guidelines, is
2. The Windfall mineral resource estimate follows the
3. These mineral resources are not mineral reserves as they have not demonstrated economic viability. The quantity and grade of reported Inferred mineral resources in this news release are uncertain in nature and there has been insufficient exploration to define these resources as indicated or measured; however, it is reasonably expected that the majority of inferred mineral resources could be upgraded to indicated mineral resources with continued exploration.
4. Resources are presented undiluted and in situ and are considered to have reasonable prospects for economic extraction. Isolated and discontinuous blocks above the stated cut-off grade are excluded from the mineral resource estimate. Must-take material, i.e. isolated blocks below cut-off grade located within a potentially mineable volume, was included in the mineral resource estimate.
5. As of
6. All core assays reported by Osisko were obtained by analytical methods described below under "Quality Control and Reporting Protocols".
7. Geological interpretation of the deposit is based on lithologies, mineralization style, alteration and structural features. Most mineralization envelopes are subvertical, striking NE-SW and plunging approximately 40 degrees towards the North-East. The 3D wireframing was generated in Leapfrog Geo, a modelling software, from hand selections of mineralization intervals. The mineral resource estimate includes a total of 556 tabular, mostly sub-vertical domains defined by individual wireframes with a minimum true thickness of 2.0 metres.
8. Assays were composited within the mineralization domains into 2.0 metres length composites. A value of 0.00125 g/t Au and 0.0025 g/t Ag (¼ of the detection limit) was applied to unassayed core intervals.
9. High-grade composites were capped. Cappings were determined in each area from statistical studies on groups of lenses sharing similar mineralization characteristics. Cappings vary from 6 g/t Au to 200 g/t Au and from 5 g/t Ag to 150 g/t Ag. A multiple capping strategy defined by capping values decreasing as interpolation search distances increase was used in the grade estimations.
10. Block models were produced using Datamine™
11. Ordinary Kriging (OK) based interpolations were produced for gold estimations in each area of the Windfall deposit, while silver grade estimations for most projects were produced using Inverse Distance Squared (ID2) interpolations. Gold estimation parameters are based on composite variography analyses. The gold estimation parameters were used for the silver estimation.
12. Density values vary between 2.73 and 2.93 and are mainly based on the densities of lithologies within the mineralized lenses.
13. The Windfall mineral resource estimate is categorized as measured, indicated and inferred mineral resource as follows:
- The measured mineral resource category is manually defined and encloses areas where:
- drill spacing is less than 12.5 metres,
- blocks are informed by a minimum of four drill holes,
- geological evidence is sufficient to confirm geological and grade continuity.
- lenses in the area have been accessed by underground workings.
- The indicated mineral resource category is manually defined and encloses areas where:
- drill spacing is generally less than 25 metres,
- blocks are informed by a minimum of two drill holes,
- geological evidence is sufficient to assume geological and grade continuity.
- The inferred mineral resource category is manually defined and encloses areas where:
- drill spacing is less than 100 metres,
- blocks are informed by a minimum of two drill holes,
- geological evidence is sufficient to imply, but not verify geological and grade continuity.
14. The mineral resource is reported at 3.5 g/t Au cut-off. The cut-off grade is based on the following economic parameters: gold price at 1,600 USD/oz, exchange rate at
15. Estimates use metric units (metres, tonnes and g/t). Metal contents are presented in troy ounces (metric tonne x grade / 31.103475).
16. The independent qualified person is not aware of any known environmental, permitting, legal, title-related, taxation, socio-political or marketing issues, or any other relevant issue, that could materially affect the mineral resource estimate.
17. Values in tonnes and ounces are rounded to nearest thousand which may cause apparent discrepancies.
Qualified Person
The Windfall mineral resource estimate, with an effective date of
Quality Control and Reporting Protocols
NQ core assays were obtained by either 1 kilogram screen fire assay or standard 50 gram fire assaying-AA finish or gravimetric finish at (i)
About the Windfall Gold Deposit
The Windfall gold deposit is located between
About
Osisko is a mineral exploration company focused on the acquisition, exploration, and development of precious metal resource properties in
Cautionary Statements Regarding Estimates of Mineral Resources
This news release uses the terms measured, indicated and inferred mineral resources as a relative measure of the level of confidence in the resource estimate. Readers are cautioned that mineral resources are not mineral reserves and that the economic viability of resources that are not mineral reserves has not been demonstrated. The mineral resource estimate disclosed in this news release may be materially affected by geology, environmental, permitting, legal, title, socio-political, marketing or other relevant issues. The mineral resource estimate is classified in accordance with the
Cautionary Note Regarding Forward-Looking Information
This news release contains "forward-looking information" within the meaning of the applicable Canadian securities legislation that is based on expectations, estimates, projections and interpretations as at the date of this news release. Any statement that involves predictions, expectations, interpretations, beliefs, plans, projections, objectives, assumptions, future events or performance (often, but not always, using phrases such as "expects", or "does not expect", "is expected", "interpreted", "management's view", "anticipates" or "does not anticipate", "plans", "budget", "scheduled", "forecasts", "estimates", "potential", "feasibility", "believes" or "intends" or variations of such words and phrases or stating that certain actions, events or results "may" or "could", "would", "might" or "will" be taken to occur or be achieved) are not statements of historical fact and may be forward-looking information and are intended to identify forward-looking information. This news release contains the forward-looking information pertaining to, among other things: the Windfall gold deposit being one of the highest-grade resource-stage gold projects in
CONTACT INFORMATION:
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Office Telephone (416) 363-8653
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