Denison, Sudbury, Ontario

Project Snapshot

Status:

Advanced exploration/past production stage

Location:

28 km southwest of Sudbury

Commodity:

Nickel, copper, platinum-group metals (PGM)

Ownership:

16.5% shareholder of Lonmin Canada - 100% interest in Denison project

Current exploration activities:

None

Mineral resources:

NI 43-101 mineral resource estimate in Q4 2020 

  • Overview

    The Denison project covers 2.5 km2 and is located the southwest corner of the Sudbury Basin, approximately 28 kilometres west-southwest of the town of Sudbury, Ontario. Wallbridge has a 16.5% ownership interest in privately-held Lonmin Canada (a wholly-owned subsidiary of Lonmin Limited - a wholly-owned subsidiary of Sibanye-Stillwater) which has a 100% interest in the Denison nickel-copper-PGM project near Sudbury. Wallbridge is the operator of the project.

    The Denison project is also known as the past producing Crean Hill mine (closed in 2002). More than 16 Mt of ore grading 1.22% Ni, 1.11% Cu, 1.92 g/t total precious metals and 5.04 g/t Ag was produced from the underground and 1 Mt grading 0.73% Ni, 0.56% Cu and 0.025% Co was produced from the open pit. 

    The project hosts multiple, well-defined PGM-rich zones that were explored after the operations were suspended. Recent drilling highlights include 1.69% Ni, 2.28% Cu and 2.37 g/t Pt, Pd and Au over 8.23 m in the 99 Shaft zone and 1.87% Ni, 0.95% Cu and 3.14 g/t Pt, Pd and Au over 6.16 m in the 109 West zone.

    The next step is to combine the historical resources with the new drilling information into a NI 43-101 compliant resource estimate for the end of 2020 and advance the project forward by completing an economic study. 

  • Brief History

    The Denison project, previously known as the Crean Hill mine operated intermittently from 1905 until 2002. The mine produced ~16 Mt of ore grading 1.22% Ni, 1.11% Cu, 1.92 g/t total precious metals and 5.04 g/t Ag from underground and 1 Mt grading 0.73% Ni, 0.56% Cu and 0.025% Co from the open pit. 

    From 2003 to 2017, the Lonmin Canada/Vale joint venture worked on defining the strike and plunge extensions of the Crean Hill 9400 Zone, the 99 zone, the 101 Zone the 109 HW Zone and discovering 109 FW Zone. Highlight intersections from this drilling included 1.69% Ni, 2.28% Cu and 2.37 g/t Pt, Pd and Au (total precious metals, “TPM”) over 8.23 m in the 99 Shaft zone and 1.87% Ni, 0.95% Cu and 3.14 g/t TPM over 6.16 m in the 109 West zone. 

  • Geology and Mineralization

    The Denison project is located in the South Range of the Sudbury Basin, straddling the contact of the Sudbury Igneous Complex (“SIC”) with the footwall (FW) Elsie Mountain Formation. At surface, the contact dips approximately 80 degrees to the north, but undulates and is overturned at depth, dipping steeply to the south. The Elsie Mountain Formation is the basal unit of the Elliot Lake Group of the Huronian Supergroup, consisting mainly of metamorphosed basalt that is significantly chlorite altered with variable epidote and rare talc. The historical Crean Hill Mine (contact-style massive to semi-massive Ni-Cu-PGM) lies on the property. The Crean Hill mine is situated within a large trough structure at the base of the SIC that contains a number of ore deposits including Crean Hill Main Orebody, Crean Hill Intermediate Orebody, Crean Hill West Orebody, Ellen Mine and Lockerby Mine, each sitting in a terrace within the larger trough. The terraces acted as traps for the sublayer norite and contact mineralization. 

    The Denison 109 FW deposit rests in the immediate footwall of the historic Crean Hill mine, with little or no separation between the norite hosted semi-massive to massive mineralization and the much lower sulphide Pt-Pd-Au mineralization in the footwall, hosted primarily in metabasalt. The mineralization is often associated with partial-melt veinlets, thought to be a thermal effect from the emplacement of the SIC and occurs with veinlets of chalcopyrite-pyrrhotite and local pentlandite near the SIC contact. 

    The 9400 Zone is coincident to and continuous with the mineralization of the Crean Hill West Orebody, where contact-style Ni-Cu rich ores have, to a great extent, been mined out. The 9400 Zone mineral envelope, as currently defined, has a strike length of 250 metres, ranges from 3 to 39 metres in width and extends from 150 to 750 metres below surface. The Ni-Cu rich and PGM poor eastern part of the 9400 Zone is in contact with the SIC, trending obliquely away from the contact into the footwall to the west. Mineralization at the eastern part consists mostly of semi-massive to massive contact-style pyrrhotite, pentlandite, and chalcopyrite. Towards the west, into the footwall, the PGM grades increase whereas the Ni and Cu grades decrease. Here, the sulfide mineralization occurs as stringers, fracture controlled within quartz-carbonate veins, disseminations within the host rock and disseminations within quartz-amphibole veins-patches that are interpreted to be partial melts. 

  • Mineral Resources (historic)

    The historic resources are typical contact and footwall-type Ni-Cu-PGM mineralization showing potential economic grades. All resource reports were internal company resource estimates that were generated for different orebodies on the project and are not compliant with NI 43-101 requirements.

    Zone

    Source

    Year

    Completed by

    Method

    Cut-off

    Category

    Tonnes

    Cu 

    %

    NI

    Co

    PT 

    g/t

    PD 

    g/t

    Au 

    g/t

    TPM 

    g/t

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

    (000’s)

     

    %

    %

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

     

    109FW

    Historic1 2015 Lonmin Internal Non-NI-43-101 Resource Estimate

    2015

    Lonmin

    OK

    C$73 NSR2

    Indicated

    384

    0.32

    0.21

    0.007

    3.33

    1.71

    0.99

    6.03

     

     

     

     

     

     

    Inferred

    4.4

    0.42

    0.33

    0.014

    1.54

    0.84

    0.5

    2.88

     

     

     

     

     

     

    Exploration Target3

    700 - 2,100

     

     

     

     

     

     

    1.0-2.0

    9400

    Historic2 2016 Lonmin Internal Non-NI-43-101 Resource Estimate

    2017

    Lonmin

    OK

    2g/t Cut-off

    Indicated

    191

    1.08

    0.77

    0.02

    2.64

    3.29

    0.85

    6.78

     

     

     

     

     

     

    Inferred

    378

    0.61

    0.51

    0.02

    3.68

    4.53

    1.33

    9.54

    101 Zone

    Historic Vale 2012 Internal PFS Report and Block Model data

    2011

    Vale

    ID

    0-C$300/tonne

    Exploration Target3,4

    150-860

    0.6 -1.3

    0.8-1.7

    0.03 - 0.06

    0.3-0.5

    0.1-0.2

    0.1

    0.5-0.8

    Contact Remnants

    Vale 2012 Internal PFS Report and Block Model data

    2011

    Vale

    OK

    0-C$300/tonne

    Exploration Target3,4

    410-7700

    0.4-0.8

    0.6-2.0

    0.02 - 0.05

    0.2-0.5

    0.1-0.3

    0.1

    0.5-1.0

    109HW

    Vale 2012 Internal PFS Report and Block Model data

    2011

    Vale

    OK

    0-C$300/tonne

    Exploration Target3,4

    270-730

    1.0 -1.5

    0.9-1.4

    0.03 - 0.05

    0.8-1.1

    0.9-1.5

    0.5-0.7

    2.1-3.3

    109 West

    No Resource Estimate

     

     

     

     

    Exploration Target

     

     

     

     

     

     

     

     

    99 Shaft Zone

    No Resource Estimate

     

     

     

     

    Exploration Target

     

     

     

     

     

     

     

     

    Total

     

     

     

     

     

    Indicated

    575

    0.57

    0.4

    0.01

    3.1

    2.23

    0.94

    6.28

     

     

     

     

     

     

    Inferred

    382

    0.61

    0.51

    0.02

    3.66

    4.49

    1.32

    9.46

     

     

     

     

     

     

    Exploration Target

    1,530 -11,390

    0.6 - 0.9

    0.7-1.9

    0.03 - 0.05

    0.4-0.5

    0.4

    0.1-0.2

    1.0-1.2

    1. The resource estimates generated by Lonmin are internal company reports and do not follow the format required by NI-43-101. The resource estimate were carried out to the highest industry standards, however only focus on Pt-,Pd- and Au-rich mineralized domains and potentially ignore significant base metal rich mineralization. Therefore, the qualified person(s) is not confident that the historic estimate is relevant and additional modelling and interpretation is required to update the historical estimate as current. A qualified person has not done sufficient work to classify the historic estimate as current mineral resources or reserves; therefore, the quailed person(s) is not treating the historical estimate as a current mineral resource or reserve.
    2. Calculated using NSR Factor of $43.5 per g/t  Pt, $19.3 per g/t Pd, $28.9 per g/t Au, $54.5 per % Cu, $0 per % Ni and $51.9 % Co.
    3. There is insufficient information available for the qualified person(s) to validate these internal company estimates in light of NI-43-101 requirements. The potential quantity and grade is conceptual in nature as the qualified person(s) has not done sufficient work to define a mineral resource and that it is uncertain if further work will result in the target being delineated as a mineral resource. 
    4. The potential quantity and grade are based a block model generated by Vale for the different zones and provided to Wallbridge by Lonmin. The upper tonnage and lower grade range is the value with not cut-off of each respective zones. The lower tonnage and higher grade range reflects a C$300/tonne cut-off using C$8.37/lbs Ni, C$3.79/lbs Cu, C$43.87/lbs Co, C$1,108/Oz, C$1,233/Oz Pd and C$1,651 Au and assuming recoveries of 85% Ni, 90% Cu, 40% Co, 66% Pt, 74% Pd and 73% Au. 
  • Maps and Figures
    Wallbridge Sudbury Basin Properties
    Denison Property 3D Long Section
    Denison Property Plan

Sign Up for News