In April 2017, Almaden announced the results of an updated Mineral Resource Estimate prepared in accordance with National Instrument 43-101 (“NI 43-101”) by Gary Giroux, P.Eng., a qualified person under the meaning of NI 43-101.
The data available for the resource estimation consisted of 545 drill holes assayed for gold and silver. Wireframes constraining mineralised domains were constructed based on geologic boundaries defined by mineralisation intensity and host rock type. Higher grade zones occur where there is a greater density of epithermal veining. These higher grade domains have good continuity and are cohesive in nature.
Of the total drill holes, 472 intersected the mineralised solids and were used to make the resource estimate. Capping was completed to reduce the effect of outliers within each domain. Uniform down hole 3 meter composites were produced for each domain and used to produce semivariograms for each variable. Grades were interpolated into blocks 10 x 10 x 6 meters in dimension by Ordinary kriging. Specific gravities were determined for each domain from drill core. Estimated blocks were classified as either Measured, Indicated or Inferred based on drill hole density and grade continuity.
Table 1- Ixtaca Zone NI 43-101 Measured, Indicated and Inferred Mineral Resource Statement
Base Case 0.3 g/t AuEq Cut-Off highlighted from January 2017 Resource Statement. Also shown are the 0.5, 0.7 and 1.0 g/t AuEq cut-off results. AuEq calculation based average prices of $1250/oz gold and $18/oz silver.
The Pre-Feasibility Study (“PFS”) describes the Mineral Reserve estimation methodology and summarizes the key assumptions used, and to which this estimate is subject. The qualified person responsible for the Mineral Reserve is Jesse Aarsen, P.Eng., of Moose Mountain Technical Services. The Mineral Reserve is a subset of the Mineral Resource comprising only measured and indicated mineral resource blocks that contribute positive economic value and that are planned for processing during the life-of-mine plan.
Table 2 – Mineral Reserves
Notes to Mineral Reserves table:
In January 2014, Almaden announced the results of an updated National Instrument 43-101 compliant Updated Mineral Resource Estimate on the Ixtaca Zone performed by Giroux Consultants Ltd.
The data available for the resource estimation consisted of 423 drill holes assayed for gold and silver. The resource is presented in gold equivalent (AuEq) ounces and cut-offs based on price ratios, as the preliminary metallurgical test work previously reported shows the potential for roughly equivalent high recoveries for both gold and silver using standard gravity and flotation recovery techniques.
Highlights of the 2014 updated estimate include:
Measured Resource: 1,351,000 AuEq ounces (599,000 Au ounces, 38,600,000 Ag ounces) using the base case 0.5 g/t AuEq cut-off comprised of 30.44 million tonnes grading at 1.38 g/t AuEq (0.61 g/t Au and 39.44 g/t Ag)
Indicated Resource: 2,182,000 AuEq ounces (1,049,000 Au ounces, 58,140,000 Ag ounces) using the base case 0.5 g/t AuEq cut-off comprised of 62.61 million tonnes grading at 1.08 g/t AuEq (0.52 g/t Au and 28.88 g/t Ag)
Inferred Resource: 717,000 AuEq ounces (362,000 Au ounces, 18,240,000 Ag ounces) using the base case 0.5 g/t AuEq cut-off comprised of 22.70 million tonnes grading at 0.98 g/t AuEq (0.50 g/t Au and 24.99 g/t Ag)
In January 2013, Almaden announced its madien Mineral Resource Estimate on the Ixtaca Zone, in accordance with N.I. 43-101 by Giroux Consultants Ltd.
The Ixtaca Zone is a gold (Au) and silver (Ag) deposit with roughly equal values per tonne of each metal. The resource estimation consisted of 225 drill holes assayed for gold and silver. It is presented in gold equivalent (AuEq) ounces and cut-offs calculated based on price ratios.
Highlights of the 2013 Maiden Resource included:
Indicated Resource: 2,019,000 AuEq ounces using the base case 0.5 g/t AuEq cutoff comprised of 56.99 million tonnes grading 1.10 g/t AuEq (0.52 g/t Au and 29.91 g/t Ag)
Inferred Resource: 1,552,000 AuEq ounces using the base case 0.5 g/t AuEq cutoff comprised of 41.53 million tonnes grading 1.16 g/t AuEq (0.56 g/t Au and 31.41 g/t Ag)