Thunder Bay North – Escape Lake Camp Aerial View
The Thunder Bay North (TBN) Project is located approximately 50km north-northeast of Thunder Bay in north-west Ontario, Canada. Rio Tinto Exploration Canada Inc. entered into the Thunder Bay North – Earn-In to Proceed option in January 2015 under which Rio Tinto is earning 70% in the project by spending up to C$20 million over five years.
Thunder Bay – Location Map
The TBN project is in the northern part of the Proterozoic Midcontinental Rift region, an important emerging Ni-Cu-PGM province. The geology of this region is analogous to that of the giant Norilsk – Talnakh Ni-Cu-PGM camp in Russia. Mineralisation has been known in the Midcontinental Rift for many years; however, until recently it appeared to be mostly of relatively low grade. The recent Eagle (3.6Mt at 3.5% Ni, 3.0% Cu & 1.6g/t Pt+Pd+Au) and Tamarack discoveries in the USA, as well as Magma’s TBN discovery, have demonstrated that higher grade mineralisation is also present and that the province has significant potential to become a major North American Ni-Cu-PGM camp.
Glacially transported ultramafic boulders containing abundant disseminated sulphides were located within the southern part of the TBN claim block in July 2001. Assays averaged 3.8g/t Pt+Pd+Au, 0.2% Ni & 0.4% Cu. The Pt:Pd ratio of the mineralisation is characteristically 1:1.
Another extensive occurrence of boulders was found on the east shore of Current Lake in 2006. These boulders appear to be in-situ, with some minor movement, possibly due to frost heave. Assay values averaged 2.3g/t Pt+Pd+Au, 0.2% Cu & 0.2% Ni.
An aeromagnetic survey of the TBN claim block was undertaken in July 2006 and identified a prominent linear anomaly beneath Current Lake. This was interpreted to reflect the source intrusion for the mineralised peridotite boulders. The survey also located “bulls-eye” magnetic anomaly southeast of Current Lake on the adjacent Beaver Lake claim.
Thunder Bay North: Plan view of resource area centred on Current Lake
Thunder Bay North: Plan view of exploration results within 6km radius of Current Lake
Drilling of the magnetic anomaly at Current Lake in December 2006, confirmed that it reflects a peridotite intrusion and is the source of the mineralised glacial boulders. The discovery drill-hole, TBND001, completed in December 2006 returned an intersection of 10.5m @ 2.8g/t Pt+Pd+Au, 0.5% Cu & 0.3% Ni.
Subsequent geophysical surveys and drilling have confirmed that the peridotite intersected in TBND001 is part of the Current Lake Intrusive Complex – an approximately 6km-long mafic-ultramafic magma conduit. In addition two further intrusive complexes have been identified to the west – the Steepledge Lake and Lone Island Lake Intrusive Complexes. The three complexes are connected by the EWC Complex which intrudes a major east-west fault structure. All these complexes are prospective for Pt-Pd-Cu-Ni deposits.
Approximately 145,000m of diamond drilling has been completed so far in the north-western part of the Current Lake Intrusive Complex. On a platinum equivalent (Pt-Eq) basis the resources are currently estimated to be:
- Indicated Mineral Resource: 9.83 million tonnes at 2.34g/t Pt-Eq for 741,000 Pt-Eq ounces
- Inferred Mineral Resource: 0.53 million tonnes at 2.87g/t Pt-Eq for 49,000 Pt-Eq ounces.
The mineralisation remains open to the east in a section of the Current Lake Intrusive Complex known as the South East Anomaly. Recent drilling immediately east of the mineral resource has extended the mineralisation a further 550m to the east. It is anticipated that infill drilling in this area will enable the estimation of additional mineral resources.
A positive scoping study (Preliminary Economic Assessment) was completed by AMEC Americas Ltd, based on a diluted open pit resource of 10Mt @1.9g/t Pt-Eq for 0.6Moz Pt-Eq. The results of this were announced on 7 February, 2011.
In addition to growing the mineral resources, engineering studies are in progress to review the underground resources with the aim of including these in the mine plan. Also, a number of alternative mineral processing routes are being studied with the aim of reducing the projects estimated capital and operating costs as well as the technical risks. The strategy is to apply potentially reduced capital and operating costs to a significantly enlarged resource base to enhance the project’s economics.
Environmental Permitting and Sustainability
The Company has been conducting Environmental Baseline Studies in the vicinity of the Thunder Bay North mineral deposit to determine current environmental conditions and monitor levels prior to any potential disturbance from advanced exploration or possible mining operations. The baseline studies will also reveal any possible effects on the environment to date resulting from other non-exploration related activity by others operating in the area. The purpose of the baseline work completed so far has been to:
- Understand fish and fish habitat conditions of lakes and streams as well as assess fish species distribution;
- Determine the background concentrations of nutrients and metals in surface waters and sediments;
- Assess and characterize the discharge characteristics of water in the project drainage area;
- Characterize soils and vegetation in the project area;
- Conduct wildlife surveys;
- Obtain a basic understanding of the socio-economics of the area around the project and the likely effects of development; and,
- Conduct an archaeological assessment of the project footprint area.
As the project advances, additional work related to the environmental assessment and permitting of the project will be carried out in accordance with Provincial and Federal approvals processes.
Thunder Bay North – Drill Pad