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Black Pine

Black Pine is a Carlin-style, sedimentary rock-hosted (Carlin-style) gold property located in Cassia County, southern Idaho.  It is host to a past-producing heap leach gold mine that operated from 1991 through 1998.  During this time, it produced approximately 435,000 ounces of gold at a historical grade of 0.7 grams per tonne from seven shallow pits.

Black Pine Idaho Map for website Dec 2017

 

In June 2016, Liberty Gold acquired the Black Pine Property from Western Pacific Resource Corporation for US$800,000 cash, 300,000 shares of Liberty Gold and a 0.5% NSR reserved to Western Pacific.  The property includes 645 federal lode claims, covering 5,088 hectares (“ha”) with drill-tested oxide gold occurrences throughout. The main gold zone encompassing the historic Black Pine mine is not subject to seasonal closures and can be accessed year-round, weather and road conditions permitting.

As a result of the sale, Liberty Gold is in possession of data for 1,874 shallow (average depth of 93 metres) historic drill holes totalling 191,500 metres, as well as over 10,000 historic surface soil and rock samples, blast hole samples and mining and engineering data.

Black Pine is underlain primarily by strata of the Pennsylvanian to Permian Oquirrh Group, which overlies Devonian and Mississippian strata on a low-angle normal fault. The Oquirrh Group is divided into a “middle plate” consisting of carbonate rocks present within a system of interleaved, low-angle thrust and normal faults, overlain by an “upper plate” consisting primarily of sandstone.  Oxidized, finely-disseminated gold mineralization has been discovered throughout the middle plate, which ranges to over 400 m thick, over an area of approximately 14 km2.  The highest gold grades in drilling are associated with calcareous siltstone in proximity to large listric normal faults.

From 2016 to late 2017, Liberty Gold compiled the extensive database and produced a 3D model of the mineralization in historic drill holes. In late 2017, twelve reverse circulation (RC) holes were drilled from five locations. The drilling validated historical results adjacent to a historical pit and more importantly, demonstrated exceptional upside beneath the limit of shallow historical drilling1

1See: Technical Report of the Black Pine Gold Project, Cassia County, Idaho, USA” effective July 23, 2018 and signed September 7, 2018, prepared by prepared by Michael M. Gustin, CPG, of Mine Development Associates of Reno, Nevada, Moira T. Smith, Ph.D., P.Geo., Vice President, Exploration and Geoscience, Liberty Gold and William A. Lepore, M.Sc., P.Geo., Senior Project Geologist, Liberty Gold, available on SEDAR or on the Liberty Gold website.

A new Plan of Operations, received February 2019, opened up access to the entire 14 km2 area of anomalous surface geochemistry and historic gold in drill holes for comprehensive drill testing.

In 2019, the drill program was designed for infill and validation of historical results, and to test prospective areas adjacent to and beneath historical drilling. Drilling identified two new discoveries, D-1 and D-2, extending gold mineralization along stratigraphic and structural corridors between the historic A and B pits and the A Basin target. The results from the 2019 drill program include some of the longest and highest-grade unmined intercepts drilled by any operator on the Black Pine property.  Highlights include[1]

At D-1 and D-2:

  • 1.78 g/t Au over 47.2 m, including: 3.24 g/t Au over 22.9 m, 9.99 g/t Au over 3.0 m and 5.73 g/t Au over 1.5 m, in LBP021.
  • 2.56 g/t Au over 41.1 m, including: 4.47 g/t Au over 19.8 m and 8.76 g/t Au over 4.6 m, in LBP029.
  • 4.39 g/t Au over 53.3 m, including: 5.76 g/t Au over 38.1 m and 12.05 g/t Au over 12.2 m, in LBP043.
  • 3.40 g/t Au over 62.5 m, including: 5.01 g/t Au over 33.5 m and 6.21 g/t Au over 21.3 m, in LBP064.
  • 3.14 g/t Au over 44.2 m, including: 6.53 g/t Au over 16.8 m and 11.3 g/t Au over 7.6 m, in LBP062.

Drilling in 2020 identified new zones of mineralisation, including: 1) the D-3 zone, located immediately west of and partially under the D-1 zone; 2) an extension of the D-1 zone to the southeast; and 3) extensions to the F-zone, located approximately 1 km to the south of D-3. Highlights from the new D-3 zone include[2]:

  • 1.98 g/t Au over 33.5 m, including 3.93 g/t Au over 15.2 m, and 1.11 g/t Au over 30.5 m in LBP127.
  • 1.44 g/t Au over 96.0 m, including 1.95 g/t Au over 32.0 m and including 5.31 g/t Au over 1.5 m and 1.86 g/t Au over 29.0 m in LBP152.
  • 1.43 g/t Au over 9.1 m and 1.20 g/t Au over 67.1 m, including 2.57 g/t Au over 16.8 m and including 8.51 g/t Au over 3.0 m in LBP138.
  • 1.41 g/t Au over 22.9m, including 1.93 g/t Au over 13.7 m and 1.51 g/t Au over 56.4 m, including 2.36 g/t Au over 24.4 m and including 5.86 g/t Au over 3 m in LBP206.
  • 1.01 g/t Au over 62.5 m, including 1.94 g/t Au over 25.9 m in LBP189.
  • 1.50 g/t Au over 27.4 m and 0.62 g/t Au over 7.6 m in LBP203.
  • 0.98 g/t Au over 80.8 m, including 2.32 g/t Au over 18.3 m and 2.19 g/t Au over 7.6 m in LBP169.

Drilling in 2020 also targeted the southeast extension of D-1, in a 400 m-long, undrilled area between the historic B and Tallman pits.  This drilling successfully identified shallow oxide mineralization, exemplified by 3.04 g/t Au over 19.8 m, including 8.54 g/t Au over 4.6 m in LBP150.

Results from five large diameter core holes drilled to support phase 3 metallurgical column testing from the D-1, D-2 and D-3 zones include[3]:

  • 3.32 g/t Au over 47.4 m, including 12.5 g/t Au over 5.8 m in LBP214C.
  • 3.62 g/t Au over 8.1 m and 1.27 g/t Au over 54.2 m, including 2.51 g/t Au over 17.0 m in LBP222C.
  • 1.12 g/t Au over 13.4 m and 3.16 g/t Au over 32.0 m in LBP207C.
  • 1.44 g/t Au over 16.5 m and 1.36 g/t Au over 15.2 m and 1.23 g/t Au over 7.6 m in LBP197C.

Through stratigraphic, structural and mineralization modeling of historic and Liberty Gold drill data and surface data, we now recognize the D-1 zone to represent mineralization in the hangingwall of a moderately-northeast-dipping, northwest-striking listric fault system, with mineralization extending over 2 km along strike.  The D-2 zone lies in the flatter, down-dip portion of the hangingwall, and measures approximately 400 x 600 m. The D-3 zone lies in the hangingwall of a similar structure that is suspected to project from the C-D Pit area north to merge with the D-1 structure north of the B Pit, over a strike length of over 2 km.  Additional drilling is planned to target gaps in the mineralized trend. 

Phase 1 large diameter metallurgical column tests were carried out in 2019 with the following results[4]:

  • Six column leach tests produced a weighted average 78.9% gold extraction. With a range up to 92.8% gold extraction[5].
  • Gold extraction was rapid, with >80% of the leachable gold extracted within the first 10 days of column leaching. 

Phase 2 metallurgical column testing was carried out on large diameter PQ core holes designed to sample a wide range of grades and rock types, primarily within the D-1 zone, with one hole in the D-2 zone and one testing historical drilling in the Rangefront Target, highlights include[6]:

  • Twenty-nine column leach tests produced a weighted average 82.9% gold extraction13. With a range up to 94.5% gold extraction. 
  • Gold extraction was rapid, with >80% of the leachable gold extracted within the first 10 days of column leaching. 
  • Percent gold extraction is well-correlated with head grade, with the highest-grade composites returning the highest extraction numbers.

Gold extraction is relatively insensitive to particle size, with the exception of one sample from the southernmost “I” pit. All other composites can be projected to coarse particle sizes approximating run of mine conditions without significant loss of gold extraction. Results generated by this program are comparable to historical column test results generated by Noranda in 1988 from oxide material obtained prior to mining

An independent maiden resource estimate for Black Pine was announced in July 20211. The Mineral Resource has an effective date of June 20, 2021, is reported in a pit shell at a cut-off grade of 0.20 grams per tonne (“g/t”) gold (“Au”) and consists of:

  • An indicated mineral resource of 1,715,000 ounces of gold at an average grade of 0.51 g/t Au and totalling 105,075,000 tonnes; and
  • An inferred mineral resource of 370,000 ounces of gold at an average grade of 0.37 g/t Au and totalling 31,211,000 tonnes.
  • A high-grade subset of the Mineral Resource using a cut-off grade of 0.5 g/t Au consists of:
    • An indicated mineral resource of 1,020,000 ounces of gold at an average grade of 1.04 g/t Au and totalling 30,520,000 tonnes; and
    • An inferred mineral resource of 134,000 ounces of gold at an average grade of 0.94 g/t Au and totalling 4,440,000 tonnes.

Seventy-four percent of the resource ounces are located in the Discovery Zone, centered on the high-grade oxide gold D-1, D-2 and D-3 discoveries. In this area in particular, a higher-grade 0.5 g/t Au cut-off resource subset of approximately 1 g/t Au will be material to enhancing project economics for the upcoming PEA. In addition, Liberty Gold’s 2021 exploration program is focused on drilling this area to extend the current pit constrained resource outward in four directions, and upgrade Inferred resource to Indicated for use in future economic studies.

1 See the “Updated Technical Report and Resource Estimate for the Black Pine Gold Project, Cassia County, Idaho, USA” effective June 20, 2021, and signed August 18, 2021. The Technical Report was prepared in accordance with National Instrument 43-101 – Standards of Disclosure for Mineral Projects by Michael Gustin, P. Geo., of MDA, a division of RESPEC, based in Reno, Nevada; Gary L. Simmons of GL Simmons Consulting LLC of Larkspur, Colorado, both independent Qualified Persons under National Instrument 43-101; and Moira Smith of Liberty Gold Corp. The report is available under the Company’s profile at www.sedar.com and is also available on the Company’s website.

2021 is a transformative year at Black Pine. Key deliverables include:

  • Maiden resource estimate published on July 13, 2021
  • PEA
  • Phase 3 Metallurgy
  • Results from a minimum 44,000 m infill, step-out and exploratory drill program (ongoing).

Moira Smith, Ph.D., P.Geo., VP Exploration and Geoscience, Liberty Gold, is the Company's designated Qualified Person within the meaning of National Instrument 43-101 Standards of Disclosure for Mineral Projects ("NI 43-101") and has reviewed and validated that the information contained herein is accurate.

Further information on Black Pine is available in the technical report entitled “Updated Technical Report and Resource Estimate for the Black Pine Gold Project, Cassia County, Idaho, USA” effective June 20, 2021, and signed August 18, 2021, prepared by Michael M. Gustin, P. Geo., of MDA, a division of RESPEC, based in Reno, Nevada, Gary L. Simmons of GL Simmons Consulting LLC of Larkspur, Colorado, both Independent Qualified Persons under National Instrument 43-101 and Moira T. Smith, Ph.D., P.Geo., Vice President, Exploration and Geoscience, Liberty Gold.

 

[1] See press release dated January 7 and January 16, 2020, and press releases in 2019 dated May 29, June 19, July 15, July 31, September 12, October 1, October 15, and November 5, 2019 for drill results from the 2019 drill program.
[2] See press releases issued in 2020 dated June 16, June 23, July 14, July 18, September 10, September 29, November 10, and December 2.
[3] See press release dated January 12, 2021.
[4] See details in press release dated June 16, 2020.
[5] Weighted average gold extraction is obtained using the following equation: (composite head grade (grams/tonnes) multiplied by extraction (%) for all head grades)/sum of all head grades.  Using arithmetic averages tends to over-represent low grade composites and under-represent high grade composites.  The arithmetic average of the six column tests is 78.0%.
[6] See details in press release dated August 18, 2020.