Highlights:
- Indicated Mineral Resource of 2.6 million tonnes grading 5.1% zinc and 23.1 g/t silver;
- Inferred Mineral Resource of 16.9 million tonnes grading 4.3% zinc and 18.2 g/t silver;
- At-surface high grade zone; amenable to open pit mining;
- Potential for resource expansion at depth and along strike.
The Logan deposit consists of fracture and vein hosted zinc-silver mineralization within a granitic intrusion.
The Mineral Resource Estimate (MRE) and NSR cut-off sensitivities are presented in Table 1 and Table 2, respectively.
Table 1 – Logan Project Open Pit Constrained Mineral Resource Estimate
Classification | Zn Cutoff (%) | Tonnes | Zn (%) | Ag (g/t) | Zn (Mlb) | Ag (Moz) |
Indicated | 1.6 | 2,620,000 | 5.1 | 23.1 | 294 | 1.94 |
Inferred | 1.6 | 16,930,000 | 4.3 | 18.2 | 1622 | 9.98 |
Notes:
- Mr.
Mike Dufresne , P.Geol.,P.Geo . ofAPEX Geoscience Ltd. , who is deemed a qualified person as defined by NI 43-101 is responsible for the completion of the updated mineral resource estimation, with an effective date ofJanuary 17, 2023 . - Mineral Resources that are not Mineral Reserves do not have demonstrated economic viability.
- The estimate of Mineral Resources may be materially affected by environmental, permitting, legal, title, taxation, socio-political, marketing, or other relevant issues.
- The Inferred Mineral Resource in this estimate has a lower level of confidence than that applied to an Indicated Mineral Resource and must not be converted to a Mineral Reserve. It is reasonably expected that the majority of the Inferred Mineral Resource could potentially be upgraded to an Indicated Mineral Resource with continued exploration.
The Mineral Resources were estimated in accordance with theCanadian Institute of Mining , Metallurgy and Petroleum (CIM), CIM Standards on Mineral Resources and Reserves, Definitions (2014) and Best Practices Guidelines (2019) prepared by theCIM Standing Committee on Reserve Definitions and adopted by theCIM Council .- The cut-off grade of 1.6% Zn is based on metal prices of
US$1.30 /lb Zn andUS$19 /oz Ag and0.77 US$ per C$, with process recoveries of 95% Zn and 80% Ag . - The constraining pit optimization parameters assumed
C$3.50 /t mineralized and waste material mining cost, 45° pit slopes and a process + G&A cost ofC$35 /t, using a 1.5 revenue factor that equates with metal price assumptions ofUS$1.95 /lb Zn,US$28.50 /Oz Ag and0.77 US$ per C$. - The effective date of the Mineral Resources Estimate is
January 17, 2023 , and a technical report on the Logan project will be filed by the Company on SEDAR within 45 days of the date of this News Release.
Table 2 – Logan Property Open Pit Constrained Mineral Resource Estimate Sensitivity
Classification | Zn Cutoff (%) | Tonnes | Zn (%) | Ag (g/t) | Zn (Mlb) | Ag (Moz) |
Indicated | 0.5 | 2,780,000 | 4.8 | 21.5 | 298 | 1.96 |
1.0 | 2,700,000 | 5.0 | 22.5 | 296 | 1.96 | |
1.6 | 2,620,000 | 5.1 | 23.1 | 294 | 1.94 | |
2.0 | 2,520,000 | 5.2 | 23.5 | 290 | 1.91 | |
3.0 | 2,060,000 | 5.8 | 26.1 | 264 | 1.73 | |
4.0 | 1,490,000 | 6.7 | 29.7 | 220 | 1.42 | |
Inferred | 0.5 | 36,640,000 | 2.4 | 10.7 | 2046 | 13.20 |
1.0 | 25,680,000 | 3.2 | 14.1 | 1864 | 11.84 | |
1.6 | 16,930,000 | 4.3 | 18.2 | 1622 | 9.98 | |
2.0 | 13,960,000 | 4.9 | 20.3 | 1505 | 9.13 | |
3.0 | 10,020,000 | 5.8 | 23.5 | 1292 | 7.56 | |
4.0 | 6,800,000 | 7.0 | 26.3 | 1045 | 5.73 |
Mineral Resource Estimation Methodology
Modeling was conducted in the Universal Transverse Mercator (UTM) coordinate space relative to the North American Datum (NAD) 1983, and UTM zone 9N. The mineral resource block model utilized a block size of 6 m (X) x 6 m (Y) x 6 m (Z) to honour the mineralization wireframes. The percentage of the volume of each block below the bare earth surface, below the modeled waste overburden surface and within each mineralization domain was calculated using the 3D geological models and a 3D surface model. For the open pit optimisation, block values were diluted. The MRE is reported as undiluted with an effective date of
The Logan Property drillhole database consists of 58 drill holes that intersected the interpreted mineralization wireframes. The zinc and silver assays were composited to 2-meter composites lengths and the estimation utilized 2,651 composited samples. A total of 1.2% of the total drilled meters inside the interpreted mineralization wireframes were not sampled, assumed to be waste, and assigned a nominal waste value of half the detection limit of modern assay methods (0.0005% Zn, 0.3429 g/t Ag).
Zinc and silver estimation was completed using Ordinary Kriging. The search ellipsoid size used to estimate the Zn and Ag grades was defined by the modelled variograms. Block grade estimation employed locally varying anisotropy, which uses different rotation angles to define the principal directions of the variogram model and search ellipsoid on a per-block basis. Blocks within estimation domains are assigned rotation angles using a modelled 3D mineralization trend surface wireframe, which allows structural complexities to be reproduced in the estimated block model. The number of variogram structures, contributions of each structure, and their ranges are set per estimation domain and do not vary within the estimation domain.
A total of 201 bulk density samples are available from the Logan Property drillhole database. APEX personnel performed exploratory data analysis of the bulk density samples available and the density was assigned for each domain in the Logan Property. The density of the deposits ranged from 2.63 g/cm³ to 2.66 g/cm³. The non-mineralized zones were assigned density based on lithological unit. The modeled overburden was assigned a density of 1.8 g/cm³ and the remaining country rock was assigned a density of 2.57 g/cm³.
The unconstrained resource block model was subjected to several open pit optimization scenarios to establish that the
There are no other known factors or issues known by the QP that materially affect the MRE other than normal risks faced by mining projects.
Comparison of Current and Historical Logan Deposit MRE
The current and historical 2012 Logan Deposit MRE use the same drill hole database (see Almadex news release dated
In addition, mineralization wireframes for the deposit were re-modeled based on lithology, alteration, and structural geology logging to include a central high grade zinc estimation domain (based on drill composite grades greater than approximately 3.5% zinc) and peripheral lower grade zinc estimation domain (based on drill composite grades greater than approximately 0.5% zinc). The 2012 historical Logan Deposit mineral resource utilized a single estimation domain also constrained by lithology, alteration, and structural geology logging of drill cores and drill composite grades greater than approximately 0.5% zinc.
Both the current and historical MRE both utilized ordinary kriging (OK) to estimate zinc and silver into 6 m (X) x 6 m (Y) x 6 m (Z) blocks in comparison to 10 m (X) x 10 m (Y) x 10 m (Z) employed during 2012.
The 2023 MRE incorporated an updated mineral resource cut-off of 1.6% zinc in comparison to 1% zinc cut-off utilized in 2012. Significantly, the 2012 historical mineral resource was not pit constrained. Open pit optimization parameters used in the current MRE are outlined above in the notes to Table 1.
Next Steps
The Logan Zn-Ag Deposit is considered to exhibit significant potential for mineral resource expansion with mineralisation open at depth on multiple drill sections, in addition to exploration potential remaining along strike. Given that exploration and delineation drilling of the Deposit occurred during the 1980’s, Almadex is assessing advances in geophysical survey equipment and 3D inversion methods; including but not limited to IP/resistivity, gravity, magnetic and electro-magnetic surveys that may assist in targeting the expansion of mineral resources and potential discovery of new exploration targets.
About the
Work on the Project completed by previous operators is briefly summarised as follows:
1979: | Staking of Logan 1 to 36 quartz mining claims to cover new zinc-silver-tin-copper gossan. Geological mapping, soil and stream sediment geochemistry, hand trenching, and test IP, EM and magnetometer geophysical surveys. |
1980-85: | Additional soil geochemistry, claim staking, hand trenching, and geophysical surveys were completed. |
1986-89: | Exploration drilling of 103 holes totalling 16,438 metres. Fifteen trenches totalling 2,412 metres and ongoing soil geochemistry and geophysical surveys. Metallurgical testwork at |
2003: | Additional staking and completion of a baseline environmental survey conducted in and around the Project. |
2006: | Bell Geospace conducted an Air Full Tensor Gravity (Air-FTG) survey. |
2012: | Wardrop, a |
QAQC and Reporting
Almadex is currently preparing the NI 43-101 Logan Project Technical Report, which will contain details of the MRE. This report is required to be announced and filed on SEDAR and the Almadex website within 45 days of this news release.
The historical zinc and lead analyses which underpin the MRE were carried out at
The QP’s conducted re-assaying of select mineralized intervals (approximately 5% of the drill database) and collected a suite of samples for specific gravity (density) determination to verify the historic drilling results. In total 232 verification samples were collected from representative mineralized intercepts geographically separated across the deposit (including 15% QA/QC duplicate, standard and blank samples) comprising 231 metres of half drill core from three separate holes from the 1986, 1987 and 1998 historical drill campaigns. Replicate samples were submitted for analysis to
The scientific and technical information contained in this news release has been reviewed and approved by
About Almadex
On behalf of the Board of Directors,
“
Chairman
Neither the
Contact Information:
Tel. 604.689.7644
Email: info@almadexminerals.com
http://www.almadexminerals.com
Figure 1:
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Figure 2:
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Figure 3:
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Figure 1: Logan Project
Location Map
Figure 2: Logan Deposit
Oblique view looking south showing higher-grade core zone
Figure 3: Logan Deposit Cross Section
Looking northeast illustrating the estimated block model zinc values and the raw zinc assays in drillholes
2023 GlobeNewswire, Inc., source