Figures

Project No.: 253821
February 2023		TOC 6

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Project No.: 253821
February 2023		TOC 7

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Trilogy Metals Inc. (Trilogy Metals) retained Wood Canada Limited (Wood) to have their Qualified Persons (QP) review and prepare an updated mineral resource statement for the Bornite property (Project) and include it in a technical report summary of an initial assessment (Report) under the mining property disclosure rules of Subpart 229.1300-Disclosure by Registrants Engaged in Mining Operations under Regulation S-K (S-K 1300).

The Bornite property is part of the Upper Kobuk Mineral Projects (UKMP) mineral tenure package, which includes the Bornite deposit, as well as numerous additional mineral showings/deposits. The property is located in the Ambler Mining District of the southern Brooks Range, in the Northwest Arctic Borough (NWAB) of Alaska. The property is located 248 km east of the town of Kotzebue, 19 km north of the village of Kobuk, and 275 km west of the Dalton Highway, an all-weather state-maintained highway. Figure 1-1 shows the location of the property.

All units of measure in this Report are metric, unless otherwise stated.

All amounts are in US dollars unless otherwise stated.

In October 2011, Trilogy Metals entered into an exploration agreement with NANA Regional Corporation, Inc. (NANA), the owner of the property, for the development of the parties’ collective resource interests in the Ambler Mining District. The agreement consolidated certain land holdings of the parties into a land package that currently totals approximately 181,387 ha of which the property contributes 97,483 ha (Bornite Property).

On February 11, 2020, Trilogy Metals transferred the UKMP to a 50/50 joint venture named Ambler Metals LLC (Ambler Metals). With NANA’s approval, Trilogy Metals also contributed, along with the UKMP, its rights under the NANA Agreement to Ambler Metals while its joint venture partner, South32 Limited (South32), contributed $145 million dedicated to advancing the development of the properties.

Project No.: 253821		Executive Summary
February 2023		Page 1-8

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

(Source: Trilogy Metals, 2013)

Mineralization in the UKMP area is characterized by two mineralized belts: the Devonian Ambler Schist Belt and the Devonian Bornite carbonate sequence. The Ambler Schist Belt is host to a series of volcanogenic massive sulphide (VMS) deposits related to metamorphosed volcanic and sedimentary rocks. Bornite Property mineralization is hosted in deformed Devonian clastic and carbonate sedimentary rocks lying immediately south of the Ambler Schist Belt across the Ambler Lowlands. Widespread hydrothermal dolomitization is characteristic of the belt and locally hosts the associated copper and cobalt mineralization.

Copper mineralization at Bornite is comprised of chalcopyrite, bornite, and chalcocite as stringers, veinlets, and breccia fillings distributed in stacked, stratabound zones exploiting favourable stratigraphy.

Cobalt mineralization at Bornite is comprised of cobaltiferous pyrite within and enveloping the copper mineralized zones and carrollite and cobaltite directly associated with copper bearing minerals.

Project No.: 253821		Executive Summary
February 2023		Page 1-9

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

The Bornite Property has been explored using integrated programs, including geologic mapping; soil, stream, and rock chip geochemistry; geophysics; underground shaft sinking and drifting; and diamond and reverse circulation drilling. Trilogy Metals geologists continue to use these integrated approaches to explore for other Bornite-style mineral systems on the Bornite Property.

There are 106,406 m of diamond drilling in 273 surface (222) and underground (51) holes completed between 1957 and 2019. Drill campaigns before 2011 were completed by Kennecott or its exploration subsidiary, Bear Creek Mining Company (BCMC), and drill campaigns since 2011 were completed by the predecessor companies to Trilogy Metals being NOVAGOLD RESOURCES INC., (NOVAGOLD), NovaCopper Inc. (NovaCopper), or Trilogy Metals.

The assay interval table contains 39,740 copper assays of which 14% are original historical values. Sampling and assaying since 2011 is supported by quality control (QC) sample result monitoring following standard industry practice. There is limited documentation available describing the sample preparation, security, analysis, and QC of drill core samples collected by Kennecott. Re-assaying of a significant amount of historical drill core which was generally confirmatory of the original assays, but did indicate a risk of a 12% high bias in zones of historical high copper grade. Only a few historical samples within the high-grade Lower Reef zone and no samples within the Upper Reef zone were re-assayed. The risk associated with the observed high bias for historical copper assays that remain in the database used for resource estimation, and the absence of any re-assaying within the Upper and Lower Reef zones is taken into consideration during mineral resource classification. Issues identified during data verification process are considered manageable by the restriction of the mineral resource to the Inferred category.

This issue discussed above only impacts the data within the Upper and Lower Reef and does not impact the South Reef.

A site visit was performed by a Wood QP.

Project No.: 253821		Executive Summary
February 2023		Page 1-10

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Metallurgical testwork to date indicates that the Bornite mineralization can be treated using standard grinding and flotation methods to produce clean copper concentrates with good results being obtained. Copper recoveries range from 87 to 90% resulting in copper concentrate grades in the range of 26 to 28% Cu.

Cobalt occurs at grades that are of potential interest but are not included in the mineral resource. A portion of the cobalt reports to the copper concentrate tails with cobalt occurring as cobaltiferous pyrite, carrollite and cobaltite.

Wood reviewed and performed validation checks on the mineral resource model and based on the results prepared a revised mineral resource statement on a 100% basis that is summarized in Table 1-1. The mineral resource estimates are based on a combination of open pit and underground mining methods and a copper price of $4.05/lb. The assumed copper price is based on Wood’s assessment of industry consensus of a long-term forecast price for mineral resource estimates. This provides a reasonable basis for establishing the prospects of economic extraction for mineral resources. The copper price used is fixed over an assumed 20-year timeframe that would be required under reasonable assumptions to mine the mineral resources. Mineral resources amenable to open pit methods are constrained within a pit shell above a marginal cut-off grade of 0.5% Cu and those amenable by underground methods are constrained within a grade shell defined by a break-even cut-off grade of 1.79% Cu. A portion of the in-pit mineral resource is well above the 1.79% Cu cut-off and would be amenable to underground mining methods providing flexibility on how to develop the deposit (Table 1-2). In the initial assessment Wood has addressed all the relevant technical and economic factors likely to influence the prospect of economic extraction to establish economic potential.

Trilogy Metals’ interest in the Bornite Property is through its 50% ownership in the Ambler Metals joint venture.

Project No.: 253821		Executive Summary
February 2023		Page 1-11

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Multiple permits are required during the exploration phase of the Bornite Property. After the formation of the joint venture, Ambler Metals has renewed the necessary permits for exploration and related camp operations.

The level of understanding of the geologic controls that influence the distribution of copper mineralization at the Bornite deposit is relatively good. The drilling, sampling and validation practices used by Trilogy Metals during the various campaigns follow accepted industry standards. Although a substantial re-assay program was conducted on the historical drill core, a high bias observed for high-grade historical copper results and the absence of direct quality control support or indirect support through re-assaying for almost all sampling within the high grade Upper and Lower Reef zones is a risk that should be resolved through re-assaying and new drilling.

Project No.: 253821		Executive Summary
February 2023		Page 1-12

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Metallurgical testwork supports that potentially marketable copper concentrates can be produced using standard grinding and flotation methods. There has been limited metallurgical testwork that evaluates the extraction of cobalt. This testwork is recommended to properly assess the potential of economic cobalt extraction and recovery that could then be used to support the inclusion of cobalt in a mineral resource.

All of the current mineral resource occurs in the Inferred category and represents an early-stage evaluation of the potential of this Bornite Property. There is an opportunity for any future mine evaluation to focus on a high-grade portion of the mineral resource (South Reef) that could be mined by underground methods only.

Based on the mineral resource estimates and existing metallurgical testwork presented in this Report, the QPs recommend Trilogy Metals continue to improve their understanding of the Bornite Property’s structural geology and their confidence in the database with additional re-sampling, drilling and database reviews, scoping study as well as conduct additional metallurgical testwork, hydrogeological and geotechnical assessments, and environmental studies totalling between $16.8 and $19.9 million.

Project No.: 253821		Executive Summary
February 2023		Page 1-13

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Trilogy Metals, a company involved in the exploration and development of projects in the UKMP in Alaska’s Ambler Mining District, retained Wood to review and prepare an updated mineral resource statement for the Bornite Property and prepare a technical report summary of an initial assessment which supports the mineral resources.

Trilogy Metals is traded on the TSX and NYSE American stock exchanges. Trilogy Metals must file a Report to support mineral resources on the Bornite Property and it must file a technical report summary with the United States Securities and Exchange Commission under S-K 1300. Wood QPs have assessed the supporting information and resource classification. The contents of this Report follow the standards and definitions of S-K 1300. This Report supports the mineral resource estimate being current as of November 30, 2022.

Wood had appropriate geology, mineral resource and mineral process QPs prepare the content of this Report.

Wood engaged its mining experts for the development of a constraining pit shell, mining underground shapes and mining costs.

Wood’s geology and resource QP visited the Bornite Property site between August 29 and September 8, 2022 in preparation for this Report. The following work was completed:

Wood’s process QP for mineral processing and metallurgical testing did not visit the Bornite Property because it is a greenfield property with no mineral process facilities to be observed.

Project No.: 253821		Introduction
February 2023		Page 2-1

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Reports and documents listed in Chapter 24 were used as sources as information to support data contained in Report. Information provided by Trilogy Metals is identified in Chapter 25.

Project No.: 253821		Introduction
February 2023		Page 2-2

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

The Bornite Property is part of the UKMP mineral tenure package, which includes the Bornite deposit as well as numerous additional mineral showings/deposits (Figure 3-1 and Figure 3-2). The Bornite Property is located in the Ambler Mining District of the southern Brooks Range in the NWAB of the State of Alaska, USA. The Bornite Property is located in Ambler River A-2 quadrangle, Kateel River Meridian T 19N, R 9E, sections 4, 5, 8 and 9.

The Bornite Property is located 248 km east of the town of Kotzebue, 19 km north of the village of Kobuk, 275 km west of the Dalton Highway (an all-weather state maintained public road) with geographic coordinates of N67.07° latitude and W156.94° longitude which is the equivalent of Universal Transverse Mercator (UTM) North American Datum (NAD) 83, Zone 4W coordinates 7440449N, 589811E.

(Source: Trilogy Metals, 2022)

Note: Ambler State Mining Claims are not part of the Bornite Property.

Project No.: 253821		Property Description
February 2023		Page 3-1

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

(Source: Trilogy Metals, 2023)

The Bornite Property consists of NANA-owned patented lands and NANA-selected ANCSA lands. A breakdown of these lands is provided in Table 3-1.

Project No.: 253821		Property Description
February 2023		Page 3-2

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

On March 22, 2004, Alaska Gold Company (Alaska Gold), a wholly owned subsidiary of NOVAGOLD, completed an Exploration and Option to Earn an Interest Agreement with Kennecott Exploration Company and Kennecott Arctic Company (collectively, Kennecott) on the Ambler land holdings.

On December 18, 2009, a Purchase and Termination Agreement was entered into between Alaska Gold and Kennecott whereby NOVAGOLD agreed to pay Kennecott a total purchase price of $29 million for a 100% interest in the Ambler land holdings, which included the Arctic deposit, to be paid as: $5 million by issuing 931,098 NOVAGOLD shares, and two installments of $12 million each, due 12 months and 24 months from the closing date of January 7, 2010.

The NOVAGOLD shares were issued in January 2010, the first $12 million payment was made on January 7, 2011, and the second $12 million payment was made in advance on August 5, 2011; this terminated the March 22, 2004 exploration agreement between NOVAGOLD and Kennecott. Under the Purchase and Termination Agreement, the seller retained a 1% net smelter return (NSR) royalty that is purchasable at any time by the landowner for a one-time payment of $10 million.

In 2011, NOVAGOLD incorporated the Trilogy Metals entities and transferred its Ambler land holdings, including the Arctic deposit, from Alaska Gold to Trilogy Metals. In April 2012, NOVAGOLD completed a spin-out of NovaCopper, with the Ambler lands, to the NOVAGOLD shareholders and made NovaCopper an independent publicly listed company, listed on the TSX and NYSE American exchanges. NovaCopper subsequently underwent a name change to Trilogy Metals Inc. in 2016.

Project No.: 253821		Property Description
February 2023		Page 3-3

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

On February 11, 2020, Trilogy Metals transferred the UKMP to a 50/50 joint venture named Ambler Metals. With NANA’s approval, Trilogy Metals also contributed, along with the UKMP, its rights under the NANA Agreement to Ambler Metals while its joint venture partner, South32, contributed $145 million dedicated to advancing the projects.

In 1971, the US Congress passed the Alaska Native Claims Settlement Act (ANCSA) which settled land and financial claims made by the Alaska Natives and provided for the establishment of 13 regional corporations to administer those claims. These 13 corporations are known as the Alaska Native Regional Corporations (ANCSA Corporations). One of these 13 regional corporations is NANA Regional Corporation, Inc. ANCSA Lands controlled by NANA bounds the southern border of the Bornite Property claim block. National Park lands are within 25 km of the northern Bornite Property border. The Bornite deposit is located entirely on lands owned by NANA.

On October 19, 2011, Trilogy Metals and NANA Regional Corporation, Inc. entered into the NANA Agreement for the cooperative development of their respective resource interests in the Ambler Mining District. The NANA Agreement consolidates Trilogy Metals’ and NANA’s land holdings into an approximately 142,831 ha land package and provides a framework for the exploration and development of the area. The NANA Agreement provides that NANA will grant Trilogy Metals the nonexclusive right to enter onto, and the exclusive right to explore, the Bornite Lands and the ANCSA Lands (each as defined in the NANA Agreement) and in connection therewith, to construct and utilize temporary access roads, camps, airstrips, and other incidental works. The NANA Agreement has a term of 20 years, with an option in favour of Trilogy Metals to extend the term for an additional 10 years. The NANA Agreement may be terminated by mutual agreement of the parties or NANA if Trilogy Metals does not meet requirements of aggregate expenditures over two consecutive calendar years are not at least $600,000 on NANA’s lands. Trilogy Metals has confirmed they met this expenditure requirement to date.

On February 11, 2020, Trilogy Metals transferred the UKMP to Ambler Metals. With NANA’s approval, Trilogy Metals also contributed, along with the UKMP, its rights under the NANA Agreement to Ambler Metals while its joint venture partner, South32 Limited contributed $145 million dedicated to advancing the projects.

Project No.: 253821		Property Description
February 2023		Page 3-4

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

The NANA Agreement outlines a partnership agreement for the development the UKMP. If, following receipt of a feasibility study and the release for public comment of a related draft environmental impact statement, Ambler Metals decides to proceed with construction of a mine on the lands subject to the NANA Agreement, Ambler Metals will notify NANA in writing and NANA will have 120 days to elect to either (a) exercise a non-transferrable back-in-right to acquire between 16% and 25% (as specified by NANA) of that specific project; or (b) not exercise its back-in-right, and instead receive a net proceeds royalty equal to 15% of the net proceeds realized by Ambler Metals from such project. The cost to exercise such back-in-right is equal to the percentage interest in the property multiplied by the difference between (i) all costs incurred by Ambler Metals or its affiliates on the property, including historical costs incurred prior to the date of the NANA Agreement together with interest on the historical costs; and (ii) $40 million (subject to exceptions). This amount will be payable by NANA to Ambler Metals in cash at the time the parties enter into a joint venture agreement and in no event will the amount be less than zero.

In the event that NANA elects to exercise its back-in-right, the parties will, as soon as reasonably practicable, form a joint venture with NANA electing to participate between 16% to 25%, and Ambler Metals will own the balance of interest in the joint venture. Upon formation of the joint venture, the joint venture will assume all obligations of Ambler Metals and be entitled to all the benefits of Ambler Metals under the NANA Agreement in connection with the mine to be developed and the related lands. A party’s failure to pay its proportionate share of costs in connection with the joint venture will result in dilution of its interest. Each party will have a right of first refusal over any proposed transfer of the other party’s interest in the joint venture other than to an affiliate or for the purposes of granting security. A transfer by either party of a NSR royalty on the property or any net proceeds royalty interest in the property other than for financing purposes will also be subject to a first right of refusal.

In connection with possible development on the Bornite Lands or ANCSA Lands, Ambler Metals and NANA will execute a mining lease to allow Ambler Metals or the joint venture to construct and operate a mine on the Bornite Lands or ANCSA Lands. These leases will provide NANA a 2% NSR royalty as to production from the Bornite Lands and a 2.5% NSR royalty as to production from the ANCSA Lands.

If Ambler Metals decides to proceed with construction of a mine on its own lands subject to the NANA Agreement, NANA will enter into a surface-use agreement with Ambler Metals which will afford Ambler Metals access to the project along routes approved by NANA (the Surface Use Agreement). In consideration for the grant of such surface use rights, Ambler Metals will grant NANA a 1% NSR royalty on production and an annual payment of $755 per acre (as adjusted for inflation each year beginning with the second anniversary of the effective date of the NANA Agreement and for each of the first 400 acres (and $100 for each additional acre) of the lands owned by NANA and used for access which are disturbed and not reclaimed.

Project No.: 253821		Property Description
February 2023		Page 3-5

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Under the NANA Agreement, NANA is required to complete a baseline environmental report following the cleanup of the former mining camp on the Bornite Lands; this work must be completed to Alaska Department of Environmental Conservation standards. Cleanup includes the removal and disposal, as required by law, of all hazardous substances present on the Bornite Lands. NANA has indemnified and will hold Trilogy Metals harmless for any loss, cost, expense, or damage suffered or incurred attributable to the environmental condition of the Bornite Lands at the date of the baseline report which relate to any activities prior to the date of the agreement.

In addition, there are no indications of any known environmental impairment or enforcement actions associated with Trilogy Metals’ activities to date. There have been environmental disturbances associated with the airstrip, shaft, trenches, camp, roads, and exploration drilling. Trilogy Metals has indicated it has not incurred outstanding environmental liabilities in conjunction with its entry into the NANA Agreement.

Reclamation of mineral exploration activities at the Bornite Property is completed under the guidelines presented by the State of Alaska in the Multi-Year Hardrock Exploration Permit #2183 issued by the Department of Natural Resources Division of Mining, Land, and Water.

Multiple permits are required during the exploration phase of the Bornite Property. Permits are issued from Federal, State, and Regional agencies, including: the Environmental Protection Agency (EPA), US Army Corps of Engineers (USACE), Alaska Department of Environmental Conservation (ADEC), Alaska Department of Fish and Game (ADF&G), Alaska Department of Natural Resources (ADNR), and NWAB. The State of Alaska permit for exploration on the Bornite Property, known as the Annual Hardrock Exploration Activity (AHEA) Permit, is obtained and renewed every five years through the ADNR – Division of Mining, Land and Water. Trilogy Metals held an AHEA exploration permit in good standing with the ADNR and has done so each year since 2004 under Alaska Gold. The Bornite Property is within the NWAB therefore requiring a Title 9 Miscellaneous Land Use permit for mineral exploration, fuel storage, gravel extraction, and the operation of a landfill. The Bornite Camp, Bornite Landfill, and Dahl Creek Camp are permitted by the ADEC. After the formation of the joint venture, Ambler Metals has renewed the necessary permits for exploration and related camp operations.

Project No.: 253821		Property Description
February 2023		Page 3-6

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

As the Bornite Project progresses, additional permits for environmental baseline and engineering studies will be necessary at Federal, State, and Regional levels.

There have been no significant violations or fines on the Bornite Property.

The QP is not aware of any significant factors and risks that may affect access, title, or the right or ability to perform work on the Bornite Property other than what is described in the Report.

Project No.: 253821		Property Description
February 2023		Page 3-7

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Primary access to the Bornite Property is by air, using both fixed-wing aircraft and helicopters.

There are four well maintained, approximately 1,500 m long gravel airstrips located near the Bornite Property, capable of accommodating charter, fixed-wing aircraft. These airstrips are located 40 km west at Ambler, 23 km southwest at Shungnak, 19 km south at Kobuk, and 15 km south at Dahl Creek. There is daily commercial air service from Kotzebue to the village of Kobuk, the closest community to the Bornite Property. During the summer months, the Dahl Creek airstrip is suitable for larger aircraft, such as C-130 and DC-6.

There is also a 700 m airstrip located at the Bornite Camp. The airstrip at Bornite is suited to smaller aircraft, which support the Bornite Camp with personnel and supplies.

There is no direct water access to the Property. During spring runoff, river access is possible by barge from Kotzebue Sound to Ambler, Shungnak, and Kobuk via the Kobuk River.

A two-lane, two-wheel drive gravel road links the Bornite Camp to the 1,525 m Dahl Creek airstrip and village of Kobuk.

The climate in the region is typical of a sub-arctic environment. Exploration is generally conducted from late May until late September. Weather conditions at the Bornite Property can vary significantly from year to year and can change suddenly. During the summer exploration season, average maximum temperatures range from 10°C to 20°C, while average lows range from -2°C to 7°C (Alaska Climate Summaries: Kobuk 1971 to 2000). By early October, unpredictable weather limits safe helicopter travel to the Bornite Property. During winter months, the Bornite Property can be accessed by snow machine, track vehicle, or fixed-wing aircraft. Winter temperatures are routinely below -25°C and can exceed -50°C. Annual precipitation in the region averages at 500 mm for elevations lower than 600 m above sea level (masl) with the most rainfall occurring from June through September, and the most snowfall occurring from November through January. Any future mine operations should be able to operate year-round with proper equipment.

Project No.: 253821		Accessibility, Climate, Local Resources, Infrastructure and Physiography
February 2023		Page 4-8

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

The Bornite Property is approximately 248 km east of the town of Kotzebue (on the edge of Kotzebue Sound), 19 km north of the village of Kobuk, 275 km west of the Dalton Highway, and 485 km northwest of Fairbanks. Kobuk (population 191; 2020 US Census) is a potential workforce source for the Bornite Property and is the location of one of the airstrips near the Bornite Property. Several other villages are also near the Bornite Property, including Shungnak located 23 km to the southwest (population of 272; 2020 US Census) and Ambler, 40 km to the west (population 274; 2020 US Census). Kotzebue (population of 3,102; 2020 US Census) is the largest population centre in the Northwest Arctic Borough. Kotzebue is a potential source of limited mining-related supplies and labourers and is the nearest centre serviced by regularly scheduled, large, commercial aircraft (via Nome or Anchorage). In addition, there are seven other villages in the region that will be potential sources of some of the workforce for the Bornite Property. Fairbanks (population 32,515; 2020 US Census) has a long mining history and can provide most mining related supplies and support that cannot be sourced closer to the Bornite Property.

Drilling and mapping programs are seasonal and have been supported out of the main Bornite Camp. The main Bornite Camp facilities are located on Ruby Creek on the northern edge of the Cosmos Hills. The camp provides office space and accommodations for the geologists, drillers, pilots, and support staff. There were four, two-person cabins installed by NANA prior to Trilogy Metals’ tenure.

The 85-person capacity Bornite Camp consists of 35 structures most of which are metal-framed, insulated tents that house multi-occupancy sleeping accommodations, kitchen facilities, dining facilities, medical services, showers, washrooms, laundry, administrative offices, and a recreation tent. Early 1960s-era legacy structures constructed by Kennecott to support Bornite shaft sinking are used for equipment maintenance, storage, and sleeping cabins.

Core is logged in two, metal-clad buildings: one from the early 1970s and one 30  m x 9  m structure that was built in 2011.

Electricity is generated at site by one 275 kW primary and one 300 kW backup diesel-powered generator.

Project No.: 253821		Accessibility, Climate, Local Resources, Infrastructure and Physiography
February 2023		Page 4-9

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Potable water is sourced from a permitted well. Solid waste disposal is accomplished by a combination of diesel-fired incineration and permitted landfill placement. The Bornite Camp’s domestic wastewater is treated in a packaged bioreactor-style treatment plant before it is discharged. Wastewater from a small portion of the camp is treated in a conventional septic system.

Currently, the Bornite Property does not have access to Alaska grid power or road access (see below). and transportation infrastructure. Power to support mine operations would have to be generated on site.

On July 23, 2020, the United States Bureau of Land Management (BLM) and the National Park Service issued the Joint Record of Decision (JROD) for the Ambler Access Project that authorizes a right-of-way across federally managed lands to the Alaska Industrial Development and Export Authority (AIDEA). The northern or “A” route, which is under consideration for a 211-mile long (340 km) controlled industrial access road in the southern Brooks Range foothills to the Ambler Mining District, was selected as part of the decision. Along with the JROD, a Section 404 Permit, which is governed by the Clean Water Act (CWA), was issued by the USACE to AIDEA. Lawsuits were filed shortly thereafter by a coalition of national and Alaska environmental non-government organizations in response to the BLM's issuance of the JROD for the Ambler Access Project.

On January 6, 2021, AIDEA signed agreements for Right-of-Ways for the Ambler Access Project with the United States Bureau of Land Management and the National Park Service. The agreements grant a 50-year right-of-way on federally owned and managed land by the federal agencies for the future development of the Ambler Access Project. During the second quarter of 2021, AIDEA signed a land access agreement with Doyon Limited to conduct feasibility and permitting activities to advance the Ambler Access Project and in September 2021 AIDEA signed a land access agreement with NANA to conduct similar activities.

In February 2021 Ambler Metals, the joint venture operating company equally owned by Trilogy Metals and South32, entered into an Ambler Access Development Agreement with AIDEA.

The Ambler Access Development Agreement defines how AIDEA and Ambler Metals will work cooperatively together on the pre-development work for the Ambler Access Project to address funding and oversight of the project’s feasibility and permitting activities until the parties reach a decision on the construction of the project. The cost of the pre-development work and activities will be paid 50% by AIDEA and 50% by Ambler Metals based on an annually agreed upon program and budget.

Project No.: 253821		Accessibility, Climate, Local Resources, Infrastructure and Physiography
February 2023		Page 4-10

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Under the Ambler Access Development Agreement, Ambler Metals and AIDEA agree to contribute up to $35 million each for pre-development costs of the Ambler Access Project through December 31, 2024. This proposed Development Agreement follows up on and is consistent with both the Interim Funding Agreement agreed to by AIDEA and Ambler Metals for pre-development work done on the project in 2020 and with the Memorandum of Understanding (MOU) between the parties signed on July 3, 2020.

On February 22, 2022, the United States Department of the Interior (DOI) filed a motion to remand the final Environmental Impact Statement (EIS) and suspend the right-of-way permits issued to AIDEA for the Ambler Access Project and in mid-March, the BLM and DOI suspended the right-of-way grant and the right-of-way permit over federal lands.

On September 20, 2022, the BLM published in the Federal Register a Notice of Intent that it will prepare a Supplemental Environmental Impact Statement (SEIS) for the proposed Ambler Mining District Industrial Access Road. The BLM anticipates publishing a draft SEIS during the second quarter of 2023 and a final SEIS within the fourth quarter of 2023.

The lawsuits have been temporarily suspended pending the additional work to be performed by the BLM on the EIS.

The Bornite Property is located on Ruby Creek on the northern edge of the Cosmos Hills. The Cosmos Hills are part of the southern flank of the Brooks Range in Northwest Alaska. Topography in the area is moderately rugged. Maximum relief in the Cosmos Hills is approximately 1,000 masl with an average of 600 masl. Talus covers much of the upper portions of the hills; glacial and fluvial sediments occupy valleys.

The Kobuk Valley is located at the transition between boreal forest and Arctic tundra. Spruce, birch, and poplar are found in portions of the valley, with a ground cover of lichens (reindeer moss). Willow and alder thickets and isolated cottonwoods follow drainages, and alpine tundra is found at higher elevations. Tussock tundra and low, heath-type vegetation covers most of the valley floor. Patches of permafrost exist on the Bornite Property.

Permafrost is a layer of soil at variable depths beneath the surface where the temperature has been below freezing continuously from a few to several thousand years (Climate of Alaska, 2007). Permafrost exists where summer heating fails to penetrate to the base of the layer of frozen ground and occurs in most of the northern third of Alaska as well as in discontinuous or isolated patches in the central portion of the state.

Project No.: 253821		Accessibility, Climate, Local Resources, Infrastructure and Physiography
February 2023		Page 4-11

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Wildlife in the Bornite Property area is typical of Arctic and Subarctic fauna (Kobuk Valley National Park, 2007). Larger animals include caribou, moose, Dall sheep, bears (grizzly and black), wolves, wolverines, coyotes, and foxes. Fish species include salmon, sheefish, arctic char, and arctic grayling. The Kobuk River, which briefly enters the UKMP on its southwest corner, is a significant salmon spawning river. The caribou on the Bornite Property belong to the Western Arctic herd that migrates twice a year: south in August from their summer range north of the Brooks Range, and north in March from their winter range along the Buckland River.

Trilogy Metals has sufficient surface rights for its planned future mining operations, including sufficient land to construct various facilities, such as tailings storage areas and potential waste disposal areas, stockpile areas and processing plants.

Project No.: 253821		Accessibility, Climate, Local Resources, Infrastructure and Physiography
February 2023		Page 4-12

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Prospectors in search of gold, travelling up the Kobuk River in 1898 to 1899 (Grinnell, 1901) found several small gold placer deposits in the southern Cosmos Hills that were worked intermittently over the ensuing decades. Around this time, copper mineralization at Ruby Creek and Pardner Hill was explored using small shafts and adits (Smith, 1913). At Ruby Creek, Smith describes bornite and chalcopyrite and lesser amounts of galena and pyrite filling open spaces in brecciated zones in limestone and in places replacing dolomite breccia.

In 1947, Rhinehart “Rhiny” Berg staked claims over the Ruby Creek prospects, carried out extensive trenching and the first diamond drilling, and constructed an airstrip for access (alaskamininghalloffame.org 2012). In 1957, BCMC, Kennecott's exploration subsidiary, optioned the property from Berg. Refer to Section 3.3.1 for further details regarding the changes of ownership of the Bornite Property.

Exploration drilling in 1961 and 1962 culminated in the discovery of the “No.1 Ore Body” where drill hole RC-34 cut 20 m of 24% Cu (the “No. 1 Ore Body” is a historical term used by BCMC that does not connote economic viability in the present context; it is convenient to continue to use the term to describe exploration work in a specific area that was previously referred to as the Ruby Creek zone and is now referred to as simply the Ruby Zone). The discovery of the “No. 1 Ore Body” led to the development of an exploration shaft in 1965 through 1966, the development of an exploration drift and the completion of underground drilling in 1967 (Section 5.1.3).

The discovery of the Arctic Project in 1965 prompted a hiatus in exploration at Bornite, and only limited drilling occurred up until 1997.

In the late 1990s, Kennecott resumed its evaluation of the Bornite deposit and the mineralization in the Cosmos Hills with an intensive soil, stream, and rock chip geochemical sampling program using a 32-element inductively coupled plasma (ICP) analyses. Grid soil sampling yielded 765 samples. Ridge and spur sampling resulted in an additional 850 soil samples in the following year. Skeletonized core samples (85 samples) from key historical drill holes were also analyzed using 32-element ICP analytical methods. Geochemical sampling identified multiple areas of elevated copper and zinc in the Bornite region (Kennecott Annual Ambler Project Reports, 1995-1997).

Project No.: 253821		History
February 2023		Page 5-1

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Kennecott completed numerous geophysical surveys as an integral part of exploration throughout its tenure on the Bornite Property. Various reports, notes, figures, and data files stored in Kennecott’s Salt Lake City exploration office indicated that geophysical work included, but was not limited to, the following:

Trilogy Metals has minimal information or documentation associated with these geophysical surveys conducted prior to the 1990s. Where data are available in these earlier surveys, the lack of details in data acquisition, coordinate systems, and data reduction procedures limit their usefulness. The only complete geophysical report that is available concerns down-hole IP/resistivity results (Merkel, 1967).

Most notable is the 1996 Bouguer gravity survey from the Bornite deposit into the Ambler Lowlands. Figure 5-1 shows the terrain-corrected Bouguer residual gravity survey anomalies. The Bornite deposit itself is seen as a significant 3 milligal anomaly. Numerous 2 milligal to >6 milligal anomalies occur under cover in the Ambler Lowlands and near the Aurora Mountain and Pardner Hill occurrences.

The wide range of geophysical techniques used in and around the deposit over a span of 40 years indicates the level of difficulty experienced by Kennecott while trying to detect mineralization. When applying EM and IP/resistivity methods, the problem appears to be that deeper mineralization is often masked by the response of near-surface conductive rocks.

In addition to the geophysical surveys conducted by Kennecott, the Alaska Department of Natural Resources and Geometries completed an aeromagnetic survey of portions of the Ambler Mining District from 1974 to 1975 (Gilbert et al., 1977). Part of this survey is reproduced in Figure 7-3.

Project No.: 253821		History
February 2023		Page 5-2

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

(Source: Trilogy Metals, 2011)

In October 1965, Kennecott began a shaft to further investigate the Ruby Zone Upper Reef “No. 1 Ore Body” mineralization. In 1966, the shaft reached the 297 m level. At this level, a 91 m crosscut was driven due north to the mineralized zone. The shaft was continued to 328 m deep to prepare a sump and loading pocket. On October 27, 1966, a small blast to excavate a bay at the bottom of the shaft opened a watercourse. The in-flow of water quickly exceeded the pump capacity and within 12 hours the 328 m shaft was flooded to within 13 m from the surface (Hawke, 1966). Prior to the shaft flooding, exploration drilling was completed from the 700-level shaft station and the 975-level shaft station and crosscut. In 1967, the shaft bottom was partially sealed and then pumped out, and additional exploration drilling completed from the 700 level and the 975 level shaft stations (see Figure 5-2 and Figure 5-3).

Project No.: 253821		History
February 2023		Page 5-3

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

(Source: Trilogy Metals, 2017)

(Source: Trilogy Metals, 2017)

Project No.: 253821		History
February 2023		Page 5-4

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Several studies have been conducted to review the geology and geochemistry of the Bornite deposit. Most notable is Murray Hitzman’s PhD dissertation at Stanford University (Hitzman, 1983) and Don Runnel’s PhD dissertation at Harvard University (Runnels, 1963). Bernstein and Cox reported on mineralization of the “No. 1 Ore Body” in a 1986 paper in Economic Geology (Bernstein et al., 1986).

In addition to the historical work, Ty Conner at the Colorado School of Mines completed a Master’s thesis which reported on the timing of alteration and mineralization at the Bornite deposit (Conner, 2015), and Zachary Mahaffey at University of Alaska Fairbanks completed a Master’s thesis on the mineralogical associations and distribution of cobalt at the Bornite deposit (Mahaffey, 2021).

Kennecott conducted two technical reviews of the groundwater conditions (Vance, 1962) and a summary of the findings related to the flooding of the exploration shaft (Erskine, 1970).

In 1961, Kennecott collected 32 coarse reject samples from five drill holes to support preliminary metallurgical testwork at Bornite. Samples targeted high-grade (>10%) copper mineralization from the Upper Reef at the Ruby Zone (Lutz, 1961). Further discussion of the historical and current metallurgical studies is presented in Chapter 10.

Project No.: 253821		History
February 2023		Page 5-5

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

The Bornite Property is located within the Arctic Alaska Terrane, a sequence of mostly Paleozoic continental margin rocks that make up the Brooks Range and North Slope of Alaska (Moore, 1992). It is within the Phyllite Belt geologic subdivision, which together with the higher metamorphic grade Schist Belt, stretches almost the entire length of the southern Brooks Range and is considered to represent the hinterland of the Jura-Cretaceous Brookian orogeny. The southern margin of the Phyllite Belt is marked by mélange and low-angle faults associated with the Kobuk River fault zone, while the northern boundary is thought to be gradational with the higher-grade metamorphic rocks of the Schist Belt (Till et al., 2008).

The tectonic setting of the project area during deposition of the host rocks (early Devonian) has been masked by subsequent Brookian deformation and remains difficult to reconstruct. Dillon et al. (1980) interpreted the existence of Devonian granites throughout the Brooks Range as supporting a volcanic arc environment, while Hitzman et al. (1986) pointed to bimodal volcanic rocks and abrupt lateral sedimentary facies transitions as supporting an extensional tectonic setting. Based on igneous geochemistry, Ratterman et al. (2006) suggest that the Ambler sequence volcanic rocks were emplaced in an extensional back-arc spreading environment; however, the original pre-deformation spatial relationship between the Bornite project area and the Ambler sequence remains poorly understood.

The project area underwent regional deformation and metamorphism during the Middle Jurassic to Early Cretaceous Brookian orogeny. The collision of the Koyukuk Arc Terrane from present-day south caused north-directed imbrication and partial subduction of the Arctic Alaska passive margin sedimentary succession. Rocks in the Schist Belt were metamorphosed to blueschist facies. The Schist Belt and the Phyllite Belt were exhumed from greenschist facies conditions during an episode of rapid extension and erosion in the Late Cretaceous beginning around 103 Ma (Moore et al., 1994; Vogl, 2003). Mapping conducted in 2021 found kinematic indicators in the Cosmos Hills that suggest these rocks have experienced top-south deformation.

In the project area, the low-angle Kobuk fault zone juxtaposes the Cosmos Hills stratigraphy (Schist Belt and Phyllite Belt) against the overlying Angayucham Terrane, and another low-angle fault likely juxtaposes the Cosmos Hills against the Ambler sequence to the north (Figure 6-1).

Project No.: 253821		Geological Setting, Mineralization and Deposit
February 2023		Page 6-1

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Bornite sequence carbonate rocks are also in low-angle fault contact with the structurally underlying Anirak schist and the overlying Beaver Creek phyllite.

(Source: Modified from Till et al., 2008 and Hitzman, 1986)

The tectonostratigraphy of the district is characterized by pelitic, carbonate and local volcanic rocks metamorphosed to lower greenschist to epidote-amphibolite facies as shown in Figure 6-1 and summarized in Table 6-1. Figure 6-2 shows a general stratigraphic column of the lithologic units in the Ruby Zone and South Reef areas.

Project No.: 253821		Geological Setting, Mineralization and Deposit
February 2023		Page 6-2

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

(Source: Modified from Hitzman et al., 1986. *Ages from Till et al., 2008)

Project No.: 253821		Geological Setting, Mineralization and Deposit
February 2023		Page 6-3

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

(Source: Trilogy Metals, 2016)

Project No.: 253821		Geological Setting, Mineralization and Deposit
February 2023		Page 6-4

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

The intersection of the Cosmos Arch and the Kogoluktuk River drainage 14 km southeast of Bornite exposes a cataclastic orthogneiss of granitic composition that intrudes the Kogoluktuk Schist and has a uranium-lead (U-Pb) zircon age of 386 ± 3 Ma (Till et al., 2008, citing W.C. McClelland).

Higher in the tectono-stratigraphic section, the Kogoluktuk Schist is intruded by sub-horizontal sill-like bodies of metagabbro of unknown age. Other metamafic greenstones are interpreted to have originated as basaltic lava flows and/or tuffaceous volcaniclastic sedimentary rocks (Hitzman, 1986).

Although none occur in the Bornite resource area, discontinuous stratabound greenstone bodies occur in the Anirak schist and at the base of the Bornite carbonate succession, particularly west and southwest of Bornite, including at Aurora Mountain and near the base of the Beaver Creek phyllite west of Bornite (Hitzman et al., 1982). A gabbroic outcrop approximately 200 m wide is exposed 2 km east of Bornite that has been interpreted to be Cretaceous to Tertiary in age.

The most significant igneous rocks in the district are the bimodal volcanic rocks of the Ambler sequence that hosts volcanic massive sulphide (VMS) deposits and outcrop 20 km north of Bornite but are not observed in the Cosmos Hills (Table 6-1). These include sub-alkaline basaltic flows and sills with an un-depleted mantle geochemical signature. Sub-alkaline rhyolitic to andesitic tuffs and flows have geochemistry consistent with derivation from a source that includes melting continental crust. Geochemical data imply an origin in an extensional, back-arc basin setting (Ratterman et al., 2006). U-Pb zircon dating from Ambler sequence metarhyolites yields ages of 387–376 Ma (McClelland et al., 2006), which are syn- to early post-mineralization with respect to the Bornite (Ruby Zone) deposit.

Sulphides (chalcopyrite, pyrite, and bornite) from Bornite (Ruby Zone) were dated by rhenium–osmium (Re-Os) techniques, yielding an age of 384 ± 4.2 Ma for main stage copper mineralization (Selby et al., 2009).

More recent work (Conner, 2015) suggests a post Jura-Cretaceous (i.e., Post-Brookian) age for mineralization based on 1) albite alteration associated with the mineralizing event cross-cuts the pronounced Jura-Cretaceous penetrative fabric at Bornite, and 2) the common presence of cymrite, a barium-rich blueschist-stable metamorphic mineral related to the Jura-Cretaceous deformation common within all the various mineralized assemblages. The Re-Os ages appear to be contradictory to the Conner (2015) geologic observations, and it seems unlikely for Re-Os to retain a syn-sedimentary age in a metamorphosed and orogenically modified terrane. The question of whether sulphides at Bornite are deformed by, cross-cut, or lie in the plane of Brookian deformation still needs to be further investigated.

Project No.: 253821		Geological Setting, Mineralization and Deposit
February 2023		Page 6-5

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

The syngenetic VMS deposits in the Ambler sequence are constrained by dating of related felsic volcanic rocks. Early post-mineral metarhyolite at the Arctic deposit yielded a mean U-Pb zircon age of 378 ± 2 Ma. Uranium-lead zircon ages for metarhyolite at the Tom-Tom prospect, 11 km east of Arctic, and the Sun prospect, 60 km east of Arctic, are 381 ± 2 Ma and 386 ± 2 Ma, respectively (McClelland et al., 2006) suggesting that felsic magmatism migrated west over time.

The geology of the Bornite resource area is composed of alternating intervals of carbonate rocks (limestone and dolostone) and calcareous phyllite. Limestone transitions laterally into dolostone near zones of mineralization and is considered hydrothermally altered. Spatial relationships and petrographic work suggest that dolomitization is genetically related to early stages of the copper mineralizing system (Hitzman, 1986); however, recent re-logging has questioned this view.

Trilogy Metals geologists have been unable to identify any meta-igneous rocks in the resource area; all lithologies described are interpreted as meta-sedimentary in origin.

The current logging system for lithology derives from early Kennecott core logs (1960). Original unit descriptions have not been found; however, the units were re-described during re-logging by NOVAGOLD geologists in the summer of 2010. The scheme encompasses not only primary lithology, but also alteration, and compositional and textural variations. Resource-scale geologic interpretation and modelling is based on the hierarchical generalization shown in Table 6-2.

Figure 6-3 shows typical dolomitized sedimentary breccias of the Bornite carbonate sequence, which are the principal host of mineralization at Bornite. Figure 6-4 shows typical phyllites of the Bornite carbonate sequence.

In 2015, Trilogy Metals tried to improve the understanding of the distribution and nature of the various lithologic units and their context within a sedimentary depositional model. A new interpretation, based on lithogeochemical signatures of the various units along with their historical visual logging, concluded that stacked debris flows composed of basal non- argillaceous channelized breccias were overlain by upward fining increasingly argillaceous breccias and capped by high calcium (Ca) phyllites occupying channels cut into either massive or thin-bedded carbonates.

Project No.: 253821		Geological Setting, Mineralization and Deposit
February 2023		Page 6-6

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Two mineralized stacked debrite successions were named the Lower and Upper Reefs. The Upper Reef grades upward into argillaceous limestones instead of discrete high Ca phyllites indicating a waning of debris supply. Based on this interpretation, a series of individual debrites were identified, and these units form the basis of the mineral resource model presented in Chapter 11.

In contrast to the locally derived high-Ca phyllites of the debrite-dominated Bornite carbonate sequence, low calcium (Ca) phyllites are abundant in the allochthonous Anirak schist (quartz phyllite) and the Beaver Creek phyllite that underlie and overlie the Bornite carbonate sequence, respectively.

Project No.: 253821		Geological Setting, Mineralization and Deposit
February 2023		Page 6-7

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

(Source: Trilogy Metals, 2017)

Project No.: 253821		Geological Setting, Mineralization and Deposit
February 2023		Page 6-8

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Figure 6-4: Typical Phyllites of the Bornite Carbonate Sequence

(Source: Trilogy Metals, 2017)

Project No.: 253821		Geological Setting, Mineralization and Deposit
February 2023		Page 6-9

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

In addition to depositional lithostratigraphy, a cross-cutting mineralized breccia called the P-Breccia has been identified in and around the South Reef deposit. Though poorly defined due to lack of drilling in the area, the P-Breccia zone—which contains excellent copper grade—lies at the apex of the Iron Mountain discontinuity. Although clearly post-deformational, it remains unclear whether the P-Breccia is a post-depositional structural, hydrothermal or solution-collapse breccia.

A short lithostratigraphic project carried out during the 2021 field season updated the interpretation of the depositional environment of the Bornite succession; this resulted in significant differences when compared to the previously summarized interpretations. The Bornite succession is now understood to be a carbonate slope deposit characterized by (a) lime mudstone, exported to the slope from a contemporaneous shallow-marine carbonate factory, variably mixed with and interlayered with (b) background argillaceous sediment that is locally carbonaceous. Superimposed on these calcite-dominated normal slope strata are locally impressive thicknesses of dolomudstone-clast conglomerate (formerly breccia). Slope limestone and siltstone-mudstone were originally centimetrically to decimetrically bedded, but are commonly ductilely deformed, producing the variably limey phyllites that exhibit sub-mm scale foliation. In contrast, the dolostone-clast conglomerates and individual dolomudstone clasts responded brittlely to Brookian stress and show no significant shearing or plastic deformation. Instead, plastic deformation is largely restricted to the various phyllitic layers around the peripheries of the dolostone bodies.

The current lithostratigraphic understanding does not support the historical Kennecott interpretation of a talus-dominated fore-reef environment for the development of the high-energy carbonate breccias. The results of the 2021 lithostratigraphy project indicate that no reef is present in the area. Although there are minor debrites of slope-derived lime mudstone and calcareous siltstone casts, the dolomudstone-clast conglomerates are not the product of the active, normal carbonate system that produced lime mud that accumulated on the slope. Instead, the dolomudstone clasts are interpreted to have been derived from anomalous faulted sea-floor scarps that exposed older, unrelated dolostone bedrock to gravitational failure, resulting in deposition of dolostone-clast conglomerates by rockfall at and near scarp bases, and their further resedimentation downslope, mixed into the calcareous slope sediment as debrites (Figure 6-5). The syn-sedimentary faults that shed the conglomerates were probably the result of extension during accumulation of the Bornite succession. They also possibly acted as later conduits for mineralizing fluids. Dolostone-clast conglomerates are the main hosts of copper mineralization at Bornite, which is concentrated where the Bornite strata are most doloclast-conglomerate-rich.

Project No.: 253821		Geological Setting, Mineralization and Deposit
February 2023		Page 6-10

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

(Source: Turner, 2021)

Structural fabrics observed on the Bornite Property include rare bedding and two distinct metamorphic foliations. Bedding (S0) can be measured only rarely where phyllite and carbonate are interbedded, and it is unclear to what extent it is transposed. The pervasive foliation (S1) is often mylonitic and exhibits both an imprinted stretching lineation and preferred top direction. It is easily measured in phyllites and is commonly reflected by colour banding and/or stylolamination (flaggy habit in outcrop) of the carbonates. Some limestone outcrops, in particular the TBLS on Aurora Mountain and the marbles at the base of Coral Hill, also exhibit a stretching lineation. Core-logging shows that S1 is folded gently on a 10 m scale and locally tightly folded at the decimetre scale forming a common S2 axial planar cleavage. S2 is folded gently on a 10 m scale forming an upright mesoscale S3 foliation. S1 and S3 foliations are thought to be Jura-Cretaceous in age.

Structural mapping in 2021 recognized a well-developed stretching lineation (i.e., L-tectonite) in the carbonate-phyllite rocks, typically oriented shallowly towards the north-northeast or south-southwest. Top directions indicate movement to the south or south-southwest along the vector of the stretching lineation. Moreover, new mapping indicates that stiff Bornite rocks, in particular metric to hectametric dolostone bodies, have been boudinaged into 3D ellipsoids. Slip is accommodated by phyllites. Interpretation of this mapping should be performed to determine whether such a tectonic style plays a role in the distribution of copper mineralization.

Project No.: 253821		Geological Setting, Mineralization and Deposit
February 2023		Page 6-11

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Owing to their greater rigidity, dolostone bodies of secondary dolostone manifest strain differently: tan hydrothermal dolostone tends to be broken into centimetre- to decimetre-scale blocks, whereas grey (diagenetic?) dolostone may exhibit unusual, contorted forms, some resembling human fingers or swan necks, as evident in outcrop. Dolostone is rarely cut by plastically deformed zones and instead forms metric to hectametric lenses (augens) encased in plastically deformed calc-mylonite and calc-phyllite. This deformation, presumably a product of the Jura-Cretaceous Brookian orogeny, complicates sedimentological interpretations.

Possibly the earliest and most prominent structural feature in the resource area is the northeast-trending Iron Mountain fault or discontinuity, which is still problematic in its interpretation because it is a cross structure that strikes northeast at a high angle to the overall Brookian structural trend, as well as that of the South Reef deposit. Numerous drill holes in the South Reef area intersect a thin zone of apparent basal quartz phyllite tectonostratigraphy overlying mineralized carbonate stratigraphy, a relationship that was also documented in a trench dug between Pardner Hill and Aurora Mountain in 2021.

Numerous explanations for the Iron Mountain discontinuity have been suggested, none of which completely accounts for all the logged observations. Inadequate drilling through the feature into lower stratigraphy and the assumption that the basal quartz phyllite is in fact the bottom has limited its resolution. Interpretations offered over time, include: 1) a normal growth fault (that would date to the Devonian); 2) a thrust fault; 3) a kink or fault-propagation fold; 4) a quartz phyllite lens intercalated within the basal part of the carbonate sequence; 5) a basement-involved drag fold formed during displacement of the Bornite sequence; and 6) a depositional unconformity. Interpretations 2 to 5 would all date to the Brookian orogeny.

Importantly, the recognition of the P-Breccia at or near the apex of the Iron Mountain discontinuity, and its interpretation as a post-depositional structural, hydrothermal, or solution-collapse breccia, suggests a post-lithification origin. Some data also suggest that the P-Breccia is a syn-depositional slump related to the Iron Mountain discontinuity and the eastern terminus of the thin QP wedge, suggesting that the Iron Mountain structure was already present during the Devonian. Although the spatial distribution of mineralization adjacent to the Iron Mountain feature is unequivocal, a direct link between the discontinuity and mineralization has yet to be demonstrated.

To the north, the Bornite carbonate sequence is in low-angle normal fault contact with the Beaver Creek phyllite along the north-dipping Beaver Creek fault. The fault, a thick, brittle structure of potentially regional significance, defines the approximately bedding-parallel contact of the structurally higher Beaver Creek phyllite with the structurally lower Bornite carbonate sequence in the immediate Bornite area. However, the fault is absent further west, where these units lie in apparent stratigraphic contact.

Project No.: 253821		Geological Setting, Mineralization and Deposit
February 2023		Page 6-12

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Both the Beaver Creek fault and the Bornite carbonate sequence were in the past thought to be cut by a series of north-trending high-angle brittle faults of apparent small displacement as shown in Figure 6-1 (Hitzman et al., 1982). These structures have not been identified in outcrop or in drilling at Bornite and are no longer thought to exist. However, recent mapping on Aurora Mountain has identified two high-angle brittle normal faults that strike northwest and west-northwest that have some 50 m to 100 m of throw across them. This set of normal faults may wind up being present in other parts of the Cosmos Hills.

Mineralization at Bornite forms tabular mineralized zones that coalesce into crudely stratabound bodies hosted in dolostone conglomerate/breccia. Two significant dolomitic horizons that host mineralization have been identified by drilling and include: 1) the Lower Reef, a substantial 100 m to 300 m thick dolomitized zone lying immediately above the basal quartz phyllite unit of the Anirak schist and 2) the Upper Reef, a 100 m to 150 m thick dolomite horizon that sits roughly 300 m higher in the section. The Lower Reef is separated from the Upper Reef by a zone of ductilely sheared phyllites up to 60 m thick.

The Lower Reef dolostone outcrops along the southern margin of the Ruby Zone and is spatially extensive throughout the deposit area. It hosts a significant portion of the shallow mineral resources in the Ruby Zone as well as higher grade mineral resources down-dip and to the northeast in the South Reef area. The Upper Reef hosts relatively high-grade mineral resources to the north in the Ruby Zone. The Upper Reef zone appears to lie at an important northeast-trending facies transition to the northwest of the main drilled area and appears to be at least partially thrust over the Lower Reef stratigraphy to the southeast.

Drill results from 2013 show dolomitization and copper mineralization in the Upper and Lower Reefs coalescing into a single unit along the northern limits of current exploration. The northeast--trending Ruby Zone and South Reef areas also coalesce into a roughly 1,000 m wide zone of >200 m thick dolomite containing significant copper mineralization dipping north at roughly 5 to 10°. The 2017 drill results show that the mineralized dolomite interval continues for at least another 700 m down-dip to the northeast from mineralization in the Upper and Lower Reefs.

Figure 6-6 shows the grade thickness (Cu% x thickness in metres) distribution of copper mineralization for the Bornite deposit.

Project No.: 253821		Geological Setting, Mineralization and Deposit
February 2023		Page 6-13

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

(Source: Trilogy Metals, 2019)

Copper mineralization at Bornite comprises chalcopyrite, bornite, and chalcocite distributed in stacked, stratabound zones exploiting favourable lithologies (conglomerate/breccia) within the Bornite sequence. Mineralization occurs, in order of increasing grade, as disseminations, irregular and discontinuous stringer-style veining, breccia matrix replacement, and stratabound massive sulphides. Figure 6-7 shows typical mineralization of the Bornite deposit characterized by chalcocite, bornite, chalcopyrite and pyrite.

Project No.: 253821		Geological Setting, Mineralization and Deposit
February 2023		Page 6-14

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

(Source: Trilogy Metals, 2017)

Note: (a) Typical high-grade chalcocite-bornite-chalcopyrite mineralization; commonly forms stringers, veinlets, disseminations, and breccia fillings; (b) Chalcocite (Cu₂S) appears dark grey to black, occurs in massive sulphide zones and typically replaces bornite. Note the boudinage of the carbonate beds in which the boudin necking zone is filled with white calcite; (c) Massive sulphide mineralization, chalcocite-bornite-chalcopyrite of the historically termed “No. 1 Ore Body” Ruby Zone Upper Reef; (d) Typical disseminated 1% and 2% pyrite in ductilely deformed Quartz Phyllite – Rock unit defines the base of the Bornite carbonate sequence, equivalent to the Anirak schist; attenuated foliation parallel white quartz stringers indicate significant ductile deformation has occurred in this unit; (e) Coarse-grained carrollite (Co₂CuS₄) appears shiny and highly reflective resembling aluminum foil and is often found associated with high-grade copper zones; (f) back-scattered electron image showing cobaltite (white rounded grains) growing on chalcopyrite (dark gray).

The distribution of copper minerals is zoned around the bottom-centre of each zone of mineralization, with bornite-chalcocite-chalcopyrite at the core progressing outward to a fringe of chalcopyrite-pyrite. Additional volumetrically minor copper minerals include carrollite, digenite, tennantite-tetrahedrite, and covellite (Bernstein and Cox, 1986). Stringer pyrite and locally significant sphalerite occur above and around the copper zones and locally massive pyrite and sparse pyrrhotite are associated with siderite alteration below copper mineralization in the Lower Reef.

Project No.: 253821		Geological Setting, Mineralization and Deposit
February 2023		Page 6-15

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Significant cobalt mineralization is found accompanying bornite-chalcocite mineralization (Chapter 7, Section 7.7). Cobalt often occurs with high-grade copper as carrollite (Co₂CuS₄) and as cobaltiferous rims on recrystallized pyrite grains (Bernstein and Cox, 1986). Preliminary geometallurgical work by Trilogy Metals showed that cobalt occurs primarily as cobaltiferous pyrite (approximately 80% of the contained cobalt) and within other cobalt minerals, such as carrollite and cobaltite (CoAsS).

In 2021, as part of his master’s thesis, Mahaffey collected detailed handheld XRF analyses on 15 drill holes. Together with reflected light petrography, electron microprobe-based compositional maps, and electron microprobe analyses (EPMA), Mahaffey identified various carrollite and cobaltite compositions, textures and associations with copper sulphides as well as their spatial distribution in the Bornite deposit (Mahaffey, 2021).

Some appreciable silver values are also found at Bornite, particularly in association with bornite-rich mineralization in the South Reef area and the Ruby Zone.

A long-held view regarding alteration at Bornite assumes that dolomite is the predominant product of hydrothermal alteration. Dolomite is particularly pronounced in 1) certain massive carbonate units; 2) the Lower and Upper Reef debris flow breccias; and 3) the P-Breccia and in some outcrops in the district, especially in the Pardner Hill area. Similar to the trend in copper grade, more intense and complete dolomitization is expressed at the base of both the Lower and Upper Reefs.

Importantly, copper grade generally has a positive correlation with the intensity of dolomite alteration expressed as Ca/Mg ratios of 0.4 to 0.67. Fe-compositions of the carbonates show a significant negative correlation with copper grade. High iron carbonate species, such as siderite and iron-rich ferroan dolomite, exhibit almost no grade, whereas low iron dolomites show strong copper mineralization.

The spatial distribution of the iron-rich dolomites is zoned with high iron siderite and ankerite localized down the plunge of the lowermost debrites in the Lower Reef. Low-iron dolomites, zoned around this basal core of high-iron dolomites, are well mineralized and form an annulus or horseshoe around the core of unmineralized iron-rich carbonates between the Ruby Zone and the South Reef area.

The overall dolomite alteration pattern suggests sourcing of a mineralizing fluid from the south and transport to the north down the principal axes of coarse-grained debris flows. Of critical importance is the limit of iron-dolomites and the strongly open down-dip extension of low-iron dolomites. This supports the possible continuation of significant grade down-dip on the combined Lower Reef/South Reef extension and could constitute a very effective targeting tool elsewhere in the district.

Project No.: 253821		Geological Setting, Mineralization and Deposit
February 2023		Page 6-16

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Alteration within the high calcium (Ca) phyllites capping successive debrites is expressed as albitization of pre-existing K-feldspar and the development of magnesium-phengite at the expense of early detrital muscovite, biotite, and chlorite. Increased albite and Mg-phengites are characteristically seen as bleaching of the high calcium (Ca) phyllites with highest intensities of alteration immediately below strong copper mineralization in the debrite breccias.

Work in 2021 suggests that dolostone (dolomite) may occur primarily or only as clasts within conglomerate (breccia) and pre-dates mineralization. Additional work is needed to resolve this important discrepancy.

Figure 6-8 in the following page shows a southwest-northeast-trending schematic cross-section across the South Reef, showing an interpretation of the geology, mineralization, and alteration from the drilling results.

The Bornite carbonate sequence, host to the mineralization at Bornite, is exposed over approximately 16 km along the north slope of the Cosmos Hills and to a lesser extent on the southern margin of the Cosmos Hills arch (Figure 6-1). Numerous areas of hydrothermal dolomitization and copper mineralization occur across the entire width of outcropping carbonates and are the focus of ongoing regional exploration by Ambler Metals. Most notable of the known prospects are the Pardner Hill and Aurora Mountain areas, where outcropping mineralization was discovered and drill-tested during the Kennecott era.

The Pardner Hill prospect is located 5 km west of Bornite (Figure 6-1) and consists of a 3 km copper (± zinc) soil and rock geochemical anomaly in rubble cropping dolostone. Kennecott drilled 16 holes in the area and defined a stratabound copper mineralized zone approximately 150 m by 400 m and varying from 5 m to 35 m thick at the southern end of the geochemical anomaly. Mineralization is cut off by a low-angle fault but remains open down-dip to the north and to the south.

Dolomitization and anomalous copper and zinc geochemistry also characterize the Aurora Mountain prospect located 6 km west of Bornite (Figure 6-1). Anomalies are distributed along a 2 km mineralized horizon about a third of which has been tested by four Kennecott-era drill holes.

Project No.: 253821		Geological Setting, Mineralization and Deposit
February 2023		Page 6-17

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Importantly, the evolving understanding of the spatial distribution of the debrite breccias and their control on fluid flow along with the alteration vectoring pattern from high- iron dolomites through progressively iron-depleted dolomites provide an important opportunity to target additional mineralization both down-dip along the Upper and Lower Reefs and in the Pardner Hill and Aurora Mountain areas.

(Source: Trilogy Metals, 2016)

Project No.: 253821		Geological Setting, Mineralization and Deposit
February 2023		Page 6-18

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Recent development of a coherent sedimentary model for the Bornite deposit suggests a carbonate slope environment with a series of debrites characterized by extremely coarse-grained conglomerates (breccias). The lateral and vertical controls on the distribution of dolostone-clast conglomerate remain poorly understood but are likely a function of underlying structural controls, such as syn-sedimentary growth faults.

The overall distribution of dolomite alteration suggests sourcing of a mineralizing fluid from the south and transport to the north. The debrites may have provided important permeability and dolomitization would have been associated with volume reduction and permeability enhancement. Texturally, mineralization occupies breccia interstices and overprints dolostone wallrock via irregular fracture patterns.

From a genetic standpoint, the geochemical trends apparent in the alteration and mineralization along the south-to-north fluid path show initial or proximal high iron, magnesium, and potassium with overall low sulphur to distal high calcium, sodium and sulphur as the system evolved. Copper is broadly zoned around the high-iron core enclosed by low-iron dolomites. Importantly, the reduced (ferrous) iron present in the early assemblage of chlorite, siderite, and pyrrhotite does not support the model that the principal metal transport mechanism was an oxidized metalliferous brine with sulphide precipitation as a result of encountering reductants such as carbonaceous and pyritic phyllites or the surrounding halo of anthraxolite and other organic-C compounds.

Copper-cobalt-silver-zinc mineralization at Bornite forms disseminations, veins, and massive sulphides in stacked, semi-stratabound bodies closely associated with secondary hydrothermal dolomitization. The cross-cutting nature of the mineralization along with the presence of early pyrite and sphalerite in sedimentary breccia clasts suggest an epigenetic origin that was temporally very close after the deposition of host strata. Re-Os dating supports this interpretation (Selby et al., 2009).

Data are limited regarding the sources and nature of the copper-rich fluids that formed the Bornite deposit, but they suggest that mineralizing fluids may have formed from the interaction of saline basin fluids with mafic volcanic rocks in the area.

Project No.: 253821		Geological Setting, Mineralization and Deposit
February 2023		Page 6-19

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Given these constraints, Bornite has characteristics similar to other districts and deposits including: the Mount Isa and McArthur River districts in Australia, the Tynagh deposit in Ireland, the Kipushi deposit in the Congo, and the Tsumeb deposit in Namibia. All of these deposits show early epigenetic characteristics, emplacement in carbonate stratigraphy, and early pyrite-dolomite alteration followed by sulphide mineralization.

These comparable deposits occur in intra-continental to continental margin settings undergoing extensional tectonics and bimodal volcanism similar to Bornite. Basin-margin faults seem to have been important in localizing mineralization (Hitzman, 1983) although basin margin structures at Bornite have not been directly identified.

An early epigenetic carbonate-hosted Cu-Co model is applicable for exploration targeting in the project area.

Project No.: 253821		Geological Setting, Mineralization and Deposit
February 2023		Page 6-20

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Exploration work completed by Kennecott (1957 through 1998) is summarized in Chapter 5. In addition to extensive drilling, Kennecott completed widespread surface geochemical sampling, regional- and property-scale mapping, and numerous geophysical surveys. Most of the data was acquired by NOVAGOLD and has formed the basis for further exploration, targeting Bornite-style mineralization in the Bornite carbonate sequence. The following sections summarizes the QP’s interpretation of the exploration information.

In 2006, NOVAGOLD contracted Fugro Airborne Surveys (Fugro) to complete a detailed helicopter DIGHEM (frequency-domain EM), magnetic and radiometric survey of the Cosmos Hills. The survey covered a rectangular block approximately 18 km by 49 km which totalled 2,852-line km. The survey was flown at 300 m line spacing with a line direction of N20E. The DIGHEM helicopter survey system produced detailed profile data of magnetics, EM responses and radiometrics (total count, uranium, thorium, and potassium) and was processed into maps of magnetics, discrete EM anomalies, EM apparent resistivity, and radiometric responses.

A report and Fugro-processed maps and grids are available (Fugro, 2007). Figure 7-1 shows total field magnetics from the survey.

In 2010, in anticipation of completing the NANA Agreement, NANA granted NOVAGOLD permission to begin low level exploration at Bornite. This consisted of re-logging and re-analyzing select drill holes using a Niton™ portable XRF. A drill section across the Bornite deposit was made using Kennecott surface diamond drill holes: RC-27, -29, -32, -35, -53, -58, -62, and -102, and underground drill hole RU-16 that were re-logged and re-analyzed in the Bornite camp in July and August 2010 (Figure 7-2).

In general, the re-logging and re-interpretation compared moderately well with the 1996 Kennecott interpretation. General relationships apparent in Figure 7-2 include: a thick area of dolomitization centred approximately at drill hole RC-60 corresponding with mineralization and surrounding and overlying the Ruby Zone Upper Reef; iron-rich dolomite, forming an inner alteration zone; and a strong stratigraphic control with mineralization occurring in dolomitized limestones immediately overlying a graphitic phyllite.

Project No.: 253821		Exploration
February 2023		Page 7-21

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Figure 7-1:     Total Field Magnetics

(Source: Fugro, 2007)

Project No.: 253821		Exploration
February 2023		Page 7-22

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Figure 7-2:       Northwest-Southeast Re-interpreted Profile Across the Bornite Deposit

(Source: NOVAGOLD, 2010)

Project No.: 253821		Exploration
February 2023		Page 7-23

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

One notable difference from the Kennecott interpretation was the recognition of a significant stratigraphic and structural discontinuity between the southeastern and northwestern parts of the section. A sharp, apparent truncation or offset of mineralization, dolomitization, and stratigraphic units across this boundary is apparent in the re-logging effort. Interpretation of the discontinuity remains unclear at this time, but it could represent either a post-mineral offset or a major facies transition or both. Interpretation of this discontinuity between the Upper and Lower Reef dolomites continues to be problematic in developing a coherent structural and stratigraphic model for the deposit.

In addition to the 2010 re-logging effort, NOVAGOLD contracted a consulting geophysicist to compile an interpreted unified airborne magnetic map for the Ambler Mining District from Kennecott, Alaska DNR, and NOVAGOLD airborne geophysical surveys (Figure 7-3).

In 2011, NOVAGOLD contracted Zonge International Inc. (Zonge) to conduct both dipole-dipole complex resistivity induced polarization (CRIP) and natural source audio-magnetotelluric (NSAMT) surveys over the northern end of Bornite to develop tools for additional exploration targeting under cover to the north.

NSAMT data were acquired along two lines totalling 5.15 line-km; one line is oriented generally north-south through the centre of the survey area and the other line is the southernmost east-west line in the survey area. CRIP data were acquired on five lines: four east-west lines and one north-south line, for a total coverage of 14.1 line-km and 79 collected CRIP stations. The initial objective of the survey was to investigate geological structures and the distribution of sulphides possibly associated with copper mineralization.

Results from the paired surveys show that wide-spaced dipole-dipole resistivity is the most effective technique to directly target the mineralization package. Broad, low-resistivity anomalies reflecting pyrite haloes and mineralization appear to define the limits of the fluid package. Well-defined and often very strong chargeability anomalies are also present but appear in part to be masked by phyllitic units which also have strong chargeability signatures. NSAMT shows similar resistivity features as the IP, but these are less well resolved.

Project No.: 253821		Exploration
February 2023		Page 7-24

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Figure 7-3:     District Airborne Magnetics Compiled from Kennecott, AK DNR and NOVAGOLD Surveys

(Source: O’Connor, 2011)

Project No.: 253821		Exploration
February 2023		Page 7-25

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Considering the success of the 2011 geophysical program, Trilogy Metals contracted Zonge to conduct a major district-wide dipole/dipole IP survey, a down-hole IP radial array survey in the South Reef area, and an extensive physical property characterization study of the various lithologies to better interpret the existing historical geophysical data.

Zonge completed 48 line-km of 200 m dipole/dipole IP during 2012, infilling and expanding on the 2011 survey, and stretching across the most prospective part of the outcropping permissive Bornite carbonate sequence. Figure 7-4 and Figure 7-5 show isometric views and an interpretation of the combined 2011 and 2012 surveys for resistivity and IP, respectively. The results show a well-defined low resistivity area associated with mineralization and variable IP signatures attributed both to mineralization and the overlying Beaver Creek phyllite. Numerous target areas occur in the immediate Bornite area with lesser targets occurring in the Aurora Mountain and Pardner Hill areas and in the far east of the survey area. During the 2012 drill program at South Reef, a single drill hole was targeted on a low resistivity area approximately 500 m to 600 m southeast of the South Reef mineralization trend. Although the drill hole intersected some dolomite alteration in the appropriate stratigraphy, no significant sulphides were encountered.

In addition to the extensive ground IP survey, Zonge also completed 9 km of down-hole radial IP using an electrode placed in drill hole RC12-0197 to further delineate the trend and potential in and around the South Reef.

Extensive physical property data, including resistivity, chargeability, specific gravity, and magnetic susceptibility were captured for use in modelling the existing ground IP and gravity surveys, and the airborne EM and magnetic surveys. In general, some broad comments can be made concerning geophysical domains in and around mineralization at Bornite. Mineralization is characterized by low resistivity <20 ohms, ambiguous but elevated, often irregular chargeability highs (>35 milliradians) marginal to the mineralization, and 3-5 milligal gravity anomalies. Mineralization appears to lie along the flanks of 20-150 nT long wave magnetic anomalies which might reflect deep-seated mafic greenstones deeper in the stratigraphy.

In addition to geophysical-focused exploration, a district-wide geologic map was compiled integrating Kennecott’s 1970s mapping of the Cosmos Hills with selective Trilogy Metals mapping in 2012.

Project No.: 253821		Exploration
February 2023		Page 7-26

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Figure 7-4:     Isometric View of 2011 and 2012 Resistivity Profiles

(Source: NovaCopper, 2012)

Figure 7-5: Isometric View of 2011 and 2012 Chargeability Profiles

(Source: NovaCopper, 2012)

Project No.: 253821		Exploration
February 2023		Page 7-27

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

The emphasis of the 2013 program was to further validate and refine the 2012 geologic map of the Cosmos Hills. A deep penetrating soil and vegetation geochemical orientation survey was completed over the South Reef deposit, using various partial leaches and pH methods. The initial, approximately 1 km test lines suggest a good response for several of the partial leaches of the soils but little response in the vegetative samples. Follow-up sampling was warranted to the north of the deposit into the Ambler Lowlands.

During 2014, exploration work was limited to a re-logging and re-sampling program of historical Kennecott drill core. Work was conducted out of the Fairbanks warehouse and is described in Section 7.16.1.2.

As a follow-up to the 2013 field program, a deep penetrating soil and vegetation geochemical survey was extended north of the deposit into the Ambler Lowlands. Trilogy Metals geologists completed a litho-geochemical desktop study and a comprehensive update to the 3D lithology model.

The 2017 field program extended the 2013 and 2015 deep penetrating geochemical (DPG) soil survey another 500 m to the northeast. The 2013 soil line was extended 1,500 m to the east to test over the covered projection of the Two Grey Hills carbonate section. The 3D lithology model was updated to incorporate the 2017 drill program results.

Trilogy Metals also completed a ground gravity survey over a 2 km by 4 km grid with 100 m station spacing over the resource area and extending northeast over the 2017 drill target area. The complete Bouguer anomaly (CBA) residual plot (removes a strong decreasing to the northeast regional gradient) shows good correlation with the Lower Reef mineralization that outcrops on surface with the gravity high gradually decreasing down-dip to the northeast.

As part of the overall gravity program, Mira Geosciences (Mira) created a petrophysical model for the Bornite deposit that synthesized the expected gravity response on surface (forward model) for the 2017 gravity stations. This forward model matches very closely with the actual survey data over the deposit area but diverges on the south end where the expected response of gravity low is actually a strong gravity high that may reflect shallow mineralization up-dip along the South Reef trend. Mira also completed a geologically constrained 3D inversion using the 2017 gravity data. Two areas of anomalously high densities (>2.9 g/cc) were identified. The first area extends up to 750 m to the east-northeast of RC17-0239, which was one of the more successful holes in 2017 and is coincident with the Iron Mountain structure. The second anomaly is located just above the Anirak contact (Lower Reef) to the west of the 2017 target area and 700 m to the north of the closest drill hole (RC-53), which is weakly mineralized along that horizon. This area falls along the northwest-southeast high-grade thickness trend.

Project No.: 253821		Exploration
February 2023		Page 7-28

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

During the 2018 field season, Trilogy Metals carried out additional DPG and a 2D seismic survey at Bornite. In addition, geophysical and geochemical data from Bornite were studied using existing datasets.

Soil sampling was completed on the westerly extension of the DPG lines on the northwestern portion of the Bornite deposit. DPG was used to assist with outlining the edges of the deposit as well as to corroborate gravity anomalies defined during the 2017 field season.

A 2D seismic survey was completed by HiSeis (3D seismic imaging) in June 2018. This 2D acquisition program was designed to test whether seismic reflection was suitable for the Bornite deposit and to understand the logistics of any future 3D seismic survey over the project area. Two 6 km 2D seismic lines, a dip line and a strike line, were acquired with a total of 792 unique source locations to attempt to image hanging wall and footwall shears; other faults and shears; folding of stratigraphy; internal (within Bornite sequence) phyllite units; facies changes within the dolostones; and direct detection of massive sulphide mineralization; and any alteration associated with mineralization. Acquisition of this 2D dataset used 500 g seismic charges as a means of producing seismic energy. All seismic vibrations were measured on a fully active line of 1,189 geophone receivers which provided up to 6 km of offset on either side of the source using the Aries I seismic acquisition system. Supporting rock property data were acquired from drill core stored in Fairbanks, Alaska.

HiSeis interpreted a zone of weak seismic reflectance (strong bleached zone) within the Bornite carbonate sequence, proximal to the Anirak schist contact. Vertical features (fault array?) extending >3 km deep were identified below this bleached zone. It was hypothesized that the bleached zone represents a zone of alteration within the carbonate sequence near vertical faults that could have acted as fluid-migration pathways. Therefore, this area was identified as prospective for hosting high-grade mineralization. Hole RC18-0254 was designed to target this area up-dip of hole RC18-0224, as the centre of this altered zone had not been adequately tested by previous drilling. The results of this test hole were positive and are discussed in the drilling results below. In conclusion, the results of the 2D survey demonstrate the ability of seismic to image stratigraphy, structure and alteration at Bornite, including zones of low reflectivity related to alteration and possibly indicative of pathways for mineralizing fluids.

Project No.: 253821		Exploration
February 2023		Page 7-29

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Mira Geosciences completed a 3D inversion model of the 100 m spaced ground gravity data that were collected over the Bornite deposit during the 2017 exploration season. Using geology to constrain the model, three areas of anomalously higher gravity were defined. Unfortunately, none of these intervals were properly tested in 2017 with two holes, those at Anomaly “B” and “C”, ending above the gravity anomalies. Two of the three identified anomalies from the 2017 inversion modelling changed in size and relative orientation with the updated geologic model. Anomaly B, which stretches to the northwest from hole RC17-0238 decreased in extent, likely the result of a thicker-than-previously-modelled Upper Reef carbonate section in RC17-0238. Anomaly C is much broader and less defined, indicating that it may be the result of underestimating the SG in the lithology model. This anomaly remains untested with the failures of drill holes RC17-0242 and RC18-0245 and should be redrilled in the future. Anomaly A is relatively unchanged and remains coincident with the Iron Mountain structure. Holes RC18-0246, RC18-0249, and RC18-0250 tested the southwest edge of the anomaly where it joins the South Reef trend. Hole RC18-0250 suggests that mineralization wanes to the east, though this hole may have just missed mineralization controlled by the Iron Mountain structure. The northeast extent of this anomaly is still considered a viable exploration target.

South32 completed a QAQC review, lithogeochemical-alteration assessment, and a vectoring/targeting exercise on downhole geochemical data on the Bornite deposit. The purpose of this exercise was to use downhole analyses to assess the geology, alteration, and mineralogy of the deposit to vector towards mineralization. The Bornite sequence can be classified into three geochemical groups including: 1) very low immobiles; 2) low immobiles; and 3) higher immobiles. The latter was then subdivided into five groups based on Al, Cr, and V concentrations. The very low and low immobile groups are predominately limestones and dolomites (including breccias), whereas increasing Al in higher immobiles represent the increasingly argillaceous/micaceous units (phyllites). High Al samples in the lower Bornite sequence can be discriminated from those in the upper sequence based on high Ni:Cu ratios. In the South Reef area, lithogeochemistry, supported Trilogy Metals’ geologic model, identified the lower, central and upper Bornite sequence units and distinguished many of the logged phyllites from breccias. The results support Trilogy Metals’ interpretation that the Ruby Zone in the Lower Reef is hosted in units corresponding to the South Reef central sequence. Interestingly, the Beaver Creek phyllite could not be distinguished geochemically from the Anirak schists.

Project No.: 253821		Exploration
February 2023		Page 7-30

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Lastly, research on stable isotopes of oxygen (δ¹⁸O) and carbon (δ¹³C), based on Conner’s 2015 Master’s thesis, continued in 2018. Conner (2015) showed that δ¹⁸O becomes depleted with alteration and mineralization in Hole RC12-0202. He concluded that a significant gradient in δ¹⁸O from unaltered marble to dolostone to carbonates is associated with the presence of sulphide mineralization and that ¹⁸O equilibrated at the highest temperature experienced by the fluid that interacted with the carbonates. To test this idea, approximately 200 samples were collected from eight drill holes to examine other parts of the Bornite deposit and from Pardner Hill (Hole PH-179). The results show a general pattern of ¹⁸O depletion with increasing depth in the upper portions of the reefs that reverses and becomes heavier toward the bottom of the reef. Nevertheless, the result of this work suggests that a reasonable correlation between mineralization and depleted δ¹⁸O exists. Also, Conner (2015) observed that there is a small population of the tan phyllite suite with the lightest δ¹³C and among the lightest δ¹⁸O. Basal tan phyllites in or near the Anirak contact show this signature at Bornite and Pardner Hill, as do some tan phyllites higher in the section. However, other tan phyllites with values close to the middle of the trends are interpreted to have possible alteration overprints or have formed from a different protolith.

In 2019, Trilogy Metals contracted Geotech Ltd. (Geotech) of Aurora, Ontario to complete VTEM Plus (versatile time domain electromagnetic) and ZTEM (z-axis tipper electromagnetic) airborne helicopter geophysical surveys over the Cosmos Hills and the Ambler VMS belt. These survey methods were a significant upgrade over the previous DIGHEM survey flown by Kennecott in 1998 over the VMS belt and the DIGHEM survey flown by NOVAGOLD over Bornite in 2006 due to greater resolution and deeper penetration ability. Magnetics were measured using a cesium vapour sensor, while radiometrics was not collected due to snow cover.

Resource Potentials PTY Ltd. (Resource Potentials), a geophysical consulting company in Perth, Australia designed the program with input from the Trilogy Metals technical team, managed the request for proposal process, supervised the survey program, and performed QAQC analysis of the data collected by Geotech. Resource Potentials also reprocessed the raw signal data from Geotech and modelled the data.

The VTEM survey was flown along 200 m spaced lines, oriented northwest-southeast over the entire Bornite carbonate sequence north of the Cosmos Arch (which hosts the Bornite deposit), with additional lines at 100 m spacing directly above the Bornite resource. A second set of perpendicular lines (southwest-northeast) were flown at 200 m spacing over just the general Bornite area. Tie lines at ~4,000 m spacing were flown perpendicular to the EM flight lines to provide control for the magnetic survey.

The VTEM results from the Bornite sequence are complex and appear to be mostly reflecting bedrock lithologies (the graphitic phyllites). The conductive plates that were modelled are generally coincident with the interpreted phyllite units, as are the apparent anomalies tested by holes RC19-0263 and RC19-0266.

Project No.: 253821		Exploration
February 2023		Page 7-31

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Trilogy Metals and South32 decided not to proceed with the 2020 exploration program due to the coronavirus pandemic. The Bornite geologic model was updated using the 2019 drill program results. The Irish Centre for Research in Applied Geosciences initiated a machine-learning geochemical modelling project to help define the controls on high-grade copper mineralization.

During the 2021 field season, the understanding of the Bornite deposit and the potential for additional deposits was advanced with a new interpretation of the carbonate sequence at Bornite and an improved structural understanding of the Cosmos Hills.

A specialist in carbonate geology from Laurentian University re-logged two fences/sections of drill holes, east-west and north-south, through the Bornite deposit, to identify, distinguish and correlate lithofacies within the Bornite sequence and to identify and distinguish different types/ages of dolomitization, including, if possible, their relation to mineralization.

Turner describes the Bornite sequence as a tectonized normal carbonate slope deposit that consists of calcitic material (lime mud) derived from a nearby shallow-marine source area, interlayered with variable amounts of background terrigenous mud (argillaceous proportion increases with distance downslope). The observed sequence includes massive lime mudstone, thin-bedded argillaceous lime mudstone, lime mudstone centimetrically interbedded with terrigenous mudstone, calcareous siltstone, and limestone-clast slope conglomerates. Brookian deformation strained these argillaceous limestone slope deposits to varying degrees producing phyllites and recrystallized, strained limestones/marbles.

Importantly, superimposed on the active limestone slope system is the local presence of dolostone-clast conglomerate. Dolostone clasts are equant and irregular; predominantly dolomudstone (locally with fossil fragments) and are likely derived from subaqueous horst blocks of pre-existing older dolostone and shed into the slope limestone system. The fault scarp(s) that shed dolostone clasts were probably part of a seafloor paleotopographic system that developed during regional extension and associated fault-mediated syn-depositional subsidence.

Project No.: 253821		Exploration
February 2023		Page 7-32

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

The Bornite succession contains sedimentary evidence of proximal-distal relationships with respect to both the bedrock doloclast source and the active carbonate slope. Proximal-distal relationships may help locate structures that delivered mineralizing fluids because dolostone conglomerates dominate the stratigraphy in the mineralized areas of the Bornite deposit. Massive sulphide distribution and characteristics suggest that syn-sedimentary faults associated with dolostone-clast conglomerates may have later served as conduits for mineralizing fluids. Turner notes that massive sulphide mineralization seems to preferentially replace matrix of dolostone-clast conglomerates, especially where the dolostone-clast conglomerates dominate the stratigraphy and that sulphides in gangue-filled hydrothermal breccia interstices and veins are also localized to dolostone-clast conglomerates (Turner, 2021).

A better understanding of the configuration of the sedimentary system is recommended as its characteristics could assist in future exploration looking for other Bornite-style deposits. This could be facilitated by developing lithostratigraphic methods to pick out sedimentological characteristics indicating proximity to ancient sea-floor fault(s), lithofacies mapping of all local and regional carbonate exposures that may be affiliated with the Bornite sequence to establish their paleogeographic implications relative to the depositional model and geophysical methods to pick out possible evidence of stratigraphic offsets in the subsurface.

Also initiated in 2021 was structural mapping around Pardner Hill and Aurora Mountain. Initial results indicate: (1) Large carbonate bodies, such as Pardner Hill, Shield Mountain, and probably also Aurora Mountain, are fault klippen in allochthonous contact with the structurally subjacent Anirak schist; (2) Dolostone bodies are typically boudinaged forming metric to hectametric 3D ellipsoids encased in ductilely deformed phyllites and, in some places, calc-mylonites (limestone protolith); (3) Top-South (to SSW) deformation at a number of outcrops in the Cosmos Hills suggest that this entire structural block may have been juxtaposed southward from the position of the Ambler Lowlands or, potentially, from off the top of the Ambler Highlands (Arctic area) during exhumation that was part of the Brookian orogeny; (4) the fault contact with the overlying Beaver Creek phyllite is likely a low-angle normal fault that cuts out of the Bornite deposit to the southeast where Beaver Creek is in structural contact with Anirak schist.

Two diamond drill holes targeting the Bornite copper-hosting carbonate sequence in the Cosmos Hills and Ambler Lowlands were completed during the 2021 field season. Hole ALL21-001 targeted the northeast projection of the Bornite carbonate sequence under cover in the Ambler Lowlands about 7 km east-northeast of Bornite. The second hole, hole RC21-0267 was located at West Bornite, along the Coxcomb Ridge - Pardner Hill saddle, 3.5 km west of the Bornite deposit.

Project No.: 253821		Exploration
February 2023		Page 7-33

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Hole ALL21-001 intercepted alternating units of limestone clastic breccia, dolostone clastic breccia, limestone and dolostone with textures similar to the Beaver Creek carbonates; alternating intervals of argillaceous phyllite, argillaceous limey phyllite, argillaceous phyllitic limestone, and argillaceous limestone clastic breccias. The phyllitic units host trace pyrite mineralization and have geochemical signatures that are similar to Beaver Creek phyllites. Unfortunately, the hole was lost at 335 m without drilling through the carbonate stratigraphy.

Hole RC21-0267 tested the down-dip projection of weakly mineralized dolomitic breccia mapped in the saddle between Coxcomb Ridge and Pardner Hill. The hole intersected argillaceous phyllite (probable Beaver Creek) followed by Bornite sequence: alternating tan phyllitic limestone, tan limey phyllite, argillaceous/carbonaceous phyllitic limestone, limestone clastic breccia, limestone, and argillaceous limestone clastic breccias and dolostone clastic breccia. Trace to locally 1% chalcopyrite, with lesser amounts of sphalerite, and tennantite/tetrahedrite occur through-out a 180 m thickness of dolostone clastic breccia, mostly as disseminations within the breccia matrix and in this carbonate veins. Within this zone a 54.9 m thick interval averages 0.165% Cu starting from 196.5 m. RC21-0267 ended in a quartz phyllite fault zone at 435 m.

During the 2022 field season, structural mapping around Pardner Hill and Aurora Mountain carried out in 2021 was extended to the south to Cosmos Mountain and to the east to Inerevuk Mountain. In addition, two holes were drilled, hole RC22-0268 at Bornite West to follow up the mineralized interval encountered during the 2021 drilling, and the other at Pardner Hill, hole PH22-0180 to test the down-dip potential of the historical Pardner Hill resource to the south. The results of these two holes are being compiled and interpreted.

Outcropping exposures of the mineralization-hosting carbonate stratigraphy along with large areas of dolomite alteration occur over approximately 18 km of strike along the northern flank of the Cosmos Hills. Historical exploration drilling focused solely on outcropping mineralization and subsurface extensions at the Bornite, Aurora Mountain, and Pardner Hill areas. Much of the carbonate belt has still yet to be evaluated. In addition, airborne geophysics completed in 2006 show the Bornite carbonate sequence and the bounding stratigraphy dip to the north under the Ambler Lowlands toward the Ambler Schist Belt. This opens a large area to explore for deposits beneath the till and recent sediments that occupy the lowlands.

Project No.: 253821		Exploration
February 2023		Page 7-14

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Exploration by Kennecott and Trilogy Metals has used a variety of methodologies. In 1996, Kennecott completed an initial gravity survey of the Ambler Lowlands showing significant gravimetric anomalies that may indicate structural dislocations and potential alteration and mineralization (Figure 5-1). In 2011, Trilogy Metals investigated both deep IP and NSAMT geophysical techniques. Results from the 2011 program led to a 2012 district-wide, 200 m dipole-dipole, deep-penetrating IP survey. Along with extensive physical property data captured for all lithologies, airborne EM and magnetic data, the IP data was used to develop a comprehensive geophysical model of the district to support future exploration targeting. In 2017, Trilogy Metals conducted a more detailed gravity survey that delineated significant north-northeast to northeast oriented structures which appear in part to control local basin morphology and mineralization.

Geochemical methods include conventional and DPG and lithogeochemical vectoring. Test lines using DPG methods with various selective partial leaches of metals proved effective in recognizing margins of South Reef mineralization at significant depths under cover. A recent analysis of the extensive ICP trace element data set at Bornite demonstrates some significant alteration vectors including iron content of various hydrothermal dolomites. Simple XRF analysis of dolomites in the field might prove effective in vectoring toward Fe-poor mineralized dolomite sections.

A better understanding of the basin development and its structural framework is critical to the exploration of Bornite-style systems. Dating of mineralization in the Ambler Mining District suggests that the Ambler schist belt that hosts the Arctic deposit and the Bornite carbonate-hosted mineralization are close to contemporaneous. However, some textural and metamorphic observations suggest a possible Jura-Cretaceous or younger age for Bornite and as such, mineralization at Bornite is suspected to slightly post-date host stratigraphy. This early and extensive syngenetic/early epigenetic signature, along with the overall fluid chemistry of the system investigated by early workers, such as Hitzman (1983 and 1986), point to large saline basin-generated fluid transport as the mechanism controlling the metallogeny of the Ambler Mining District. Importantly, similar metallogenies related to saline, basin-generated fluids and their associated deposits form some of the largest copper districts in the world.

From 1957 to 2019, a total of 273 holes targeted the Bornite deposit during 24 different campaigns; 222 surface core holes and 51 underground core holes were drilled, totalling 106,406 m. All drill campaigns prior to 2011 were completed by Kennecott or its exploration subsidiary, BCMC, and the drill campaigns since 2011 were completed by NOVAGOLD (2011), NovaCopper (2012 and 2013) or Trilogy Metals. The drill campaigns are summarized in Table 7-1. The distribution of drilling by year is shown in Figure 7-6.

Split core from all drill holes, except for Kennecott-era drill holes resampled from 2012 to 2014 by NovaCopper/Trilogy and RC13-230 and RC13-232, has been retained in a storage facility at site for future reference or to provide material for metallurgical studies.

Project No.: 253821		Exploration
February 2023		Page 7-15

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Year		Surface Drill Holes				Underground Drill Holes				Metres				Operator		Core Size		Drill Contractor
1957			8				-				1,749			BCMC		AX		Sprague and Henwood
1958			10				-				2,150			Kennecott/BCMC		AX		Sprague and Henwood
1959			15				-				4,932			Kennecott/BCMC		AX & BX		Sprague and Henwood
1960			14				-				4,482			Kennecott/BCMC		AX & BX		Sprague and Henwood
1961			33				-				13,590			Kennecott/BCMC		AX, BX, & NX		Sprague and Henwood
1962			24				-				8,450			Kennecott/BCMC		AX, BX, & NX		Sprague and Henwood
1963			1				-				396			Kennecott/BCMC		BX		Sprague and Henwood
1966			0				26				1,384			Kennecott/BCMC		EX & AX		Sprague and Henwood
1967			0				21				1,862			Kennecott/BCMC		EX & AX		Sprague and Henwood
1968			8				4				3,210			Kennecott/BCMC		BX & AX		Sprague and Henwood
1969			2				-				781			Kennecott/BCMC		BX		Sprague and Henwood
1970			2				-				733			Kennecott/BCMC		BX		Sprague and Henwood
1971			2				-				829			Kennecott/BCMC		BX?		Sprague and Henwood
1972			1				-				466			Kennecott/BCMC		BX?		Sprague and Henwood
1974			2				-				702			Kennecott/BCMC		NX & BX		Sprague and Henwood
1975			1				-				316			Kennecott/BCMC		NX & BX		Sprague and Henwood
1976			6				-				2,170			Kennecott/BCMC		NXWL & BXWL		Sprague and Henwood
1997			3				-				928			Kennecott/BCMC		NX & HQ		Tonto
2011			14				-				5,819			NOVAGOLD		NQ & HQ		Boart Longyear
2012			23				-				16,046			NovaCopper		NQ & HQ		Boart Longyear
2013			17				-				8,140			NovaCopper		NQ & HQ		Boart Longyear
2017			11				-				9,302			Trilogy Metals		NQ & HQ		Tuuq & Major Drilling
2018			15				-				10,363			Trilogy Metals		NQ & HQ		Tuuq & Major Drilling
2019			10				-				7,610			Trilogy Metals		NQ & HQ		Major Drilling
Total			222				51				106,406

 

Project No.: 253821		Exploration
February 2023		Page 7-16

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

(Source: SIM et al., 2022)

In the summer of 2017, Trilogy Metals initiated eleven holes, but four were abandoned due to drilling problems. The seven remaining drill holes stepped-out to the north for distances between 250 m to 400 m from the previous drill holes; these were distances considered too far to support the estimation of mineral resources at that time.

In the summer of 2018, Trilogy Metals conducted a drilling program that included the completion of 12 holes that infilled gaps in previous drilling in the northern, down-dip part of the deposit as well as in the central area between the Ruby Zone and South Reef area. Three additional holes were collared but were abandoned due to drilling problems.

In the summer of 2019, Trilogy Metals completed another drilling program comprising eight holes that tested the continuity of the mineralization within the Bornite deposit and two holes that tested exploration targets located about 1 km south and southeast of the deposit.

Project No.: 253821		Exploration
February 2023		Page 7-17

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Between 2012 and 2014, Trilogy Metals geologists re-logged and re-sampled legacy drill holes in the Ruby Zone and South Reef area which were previously drilled and only selectively sampled by Kennecott. Table 7-2 summarizes the target areas and drill holes by year. These assays were used in the estimation of the current mineral resource, except where duplicates of Kennecott samples were collected. In the case of duplicates, the original assay information was given priority in the mineral resource database.

In the initial years of drilling at Bornite, Kennecott relied on AX diameter core (30.2 mm diameter), but, as drilling migrated towards deeper targets, a change to BX diameter core (41.3 mm diameter) was implemented to help limit deviation.

From 1966 to 1967, drilling activity at Bornite moved underground, and EX diameter core (21.5 mm diameter) was implemented to define the Ruby Zone Upper Reef “No. 1 Ore Body”. In 1968, drilling activity moved back to the surface and from 1968 to 1972, BX diameter core was most commonly drilled.

In later years, core size increased to NX (54.0 mm diameter) and finally, in 2011, core size increased to NQ (47.6 mm diameter) and HQ (63.5 mm diameter). Over the years, progressively larger diameter drill rods have been used in an effort to minimize drill hole deviations.

The Kennecott/BCMC and Trilogy Metals drilling was conducted with drill equipment that used imperial measurement units. For the purposes of data management, all imperial units were converted to metric units in the Trilogy Metals database. Trilogy Metals works exclusively in metric units.

Project No.: 253821		Exploration
February 2023		Page 7-18

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

There is limited information with respect to the specific drill core handling procedures used by BCMC/Kennecott. All drill data collected during 1957 to 1997 were logged on paper drill logs, with copies stored in the Kennecott office in Salt Lake City, Utah. Electronic, scanned copies of the paper logs are held by Trilogy Metals and stored in the Fairbanks field office.

Drill core was sawed or split in half with a splitter; half was submitted to various assay laboratories and the remainder was stored in the Kennecott/BCMC core storage facility at the Bornite deposit. In 1995, Kennecott converted the drill assay data, geologic core logs, and down-hole collar survey data into an electronic format. In 2009, NOVAGOLD geologists verified the geologic data from the original paper logs against the Kennecott electronic format and then merged the data into a Microsoft™ SQL database.

Sampling of drill core by Kennecott/BCMC focused primarily on the moderate- to -high grade mineralized zones. Intervals of visible sulphide mineralization containing roughly >0.5% to 1% Cu were selected for analysis by Union Assay Office Inc. of Salt Lake City, Utah. This approach left numerous intervals, containing weak to moderate copper mineralization, un-sampled in the historical drill core. During the 2012 exploration program, Trilogy Metals began sampling a portion of this remaining drill core in select holes in the South Reef area. Trilogy Metals extended this sampling program to the Ruby Zone in 2013 and 2014.

The following core handling procedures have been implemented (including programs conducted by NOVAGOLD and NovaCopper). Core is slung by helicopter or transported by truck or all-terrain vehicle from the drill rig to the core-logging facility. Upon delivery, geologists and geo-technicians open and inspect the core boxes for any irregularities. They first mark the location of each drilling block on the core box, and then convert footages on the blocks into metric equivalents. Geo-technicians or geologists measure the intervals (or from/to) for each box of core and include this information, together with the drill hole ID and box number, on a metal tag stapled to the end of each box.

Geo-technicians then measure the core to calculate percent recovery and rock quality designation (RQD). RQD is the sum of the total length of all pieces of core in a run over 12 cm. The total length of core in each run is measured and compared to the corresponding run length to determine percent recovery.

Project No.: 253821		Exploration
February 2023		Page 7-19

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Core is then logged with lithology and visual alteration features captured on observed interval breaks. Mineralization data, including total sulphide species (recorded as percent), sulphide type (recorded as a relative amount), and gangue and vein mineralogy are collected for each sample interval with an average interval of approximately 2 m. Structural data is collected as point data.

Geologists then mark sample intervals to indicate each lithology or other geologically appropriate intervals. Sample intervals of core are typically between 1 m and 3 m long but are not to exceed 3 m long. Occasionally, if warranted by the need for better resolution of geology or mineralization, smaller sample intervals have been used. Geologists staple sample tags on the core boxes at the start of each sample interval and mark the core itself with a wax pencil to designate sample intervals. This sampling approach is considered sound and appropriate for this style of mineralization and alteration.

Drill core is digitally photographed prior to sampling.

Drill core is cut in half using diamond core saws. Specific attention to core orientation is maintained during core sawing to ensure that representative samples are obtained. One-half of the core is retained in the core box for storage on site or at Trilogy Metals' Fairbanks warehouse, and the other half is bagged and labelled for analysis. Samples are selected for specific gravity measurements as discussed in Chapter 8.

In 2013 and 2014, 33 historical drill holes and 37 historical drill holes, respectively, in the Ruby Zone area were re-logged, re-sampled, and re-assayed because these holes had only been selectively sampled by Kennecott. Entire holes were re-logged using Trilogy Metals protocols discussed above. Samples were submitted either as half-core where previously sampled or whole core where un-sampled (to ensure that a sufficient volume of material was provided for analysis). Sample intervals were matched to legacy intervals whenever possible or selected to reflect Trilogy Metals sampling procedures described above.

The objectives of the re-assay/re-logging program were threefold: to implement a QAQC program on intervals previously sampled by Kennecott to confirm the validity of its results; to identify additional lower grade (0.2% to 0.5% Cu), which was not previously sampled; and to provide additional multi-element ICP data to assist in the geologic interpretation of the deposit. A further discussion of the program and its results are incorporated into Chapters 8 and 11.

The 2011 through to 2014 and 2017 NOVAGOLD/Trilogy Metals diamond drilling and re-logging/re-sampling programs used a commercial, computer-based core-logging system for data capture (GeoSpark Logger^© developed by GeoSpark Consulting Inc. (Geospark)). During each drill program, all logging data was captured on individual laptops in a Microsoft™ SQL database and then validated and merged into the Bornite camp server. In 2012, the system was modified to allow each laptop to sync daily to the Data Logger database residing on the Bornite camp server. The server was periodically backed up, and the database was sent to Vancouver, British Columbia for integration into the master database. The camp server was stored in the Fairbanks field office at the end of each field season. Hardcopies of the 2011 through 2013 drill core logs are stored in the Fairbanks office.

Project No.: 253821		Exploration
February 2023		Page 7-20

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary

Generally, core recovery has been very good throughout all drilling programs conducted at Bornite. Overall recoveries average 88%, with recoveries in the early programs, conducted in the 1950s through 1970s averaging >86%, and recoveries in drilling since 2011 averaging 90%. There is minimal difference in core recovery by rock type, with phyllites averaging 87% recovery and dolomites averaging 89% recovery. There is no apparent relationship between recovery and grade in the database. There were no adjustments or omissions to the mineral resource database in response to drill core recoveries.

Kennecott provided NOVAGOLD with collar coordinates for all legacy holes in UTM coordinates using the NAD27 datum. During the 2011 field season, the collar locations of 63 legacy surface holes were re-surveyed in UTM NAD83 zone 4N datum. The results of this re-survey were compared to the original Kennecott collar survey data as follows:

Project No.: 253821		Exploration
February 2023		Page 7-21

	Bornite Project
	Northwest Alaska, USA
	S-K 1300 Technical Report Summary