VANCOUVER — The geology of eastern Canada largely owes itself to a series of events that began 480 million years ago, when the Iapetus Ocean (analogous to today’s Atlantic Ocean) closed and ancestral North America collided with the North African craton to make the supercontinent Pangaea.
The collision marked the birth of the Appalachian Mountains — a belt of folded and thrusted sedimentary rocks, comingled with slivers of an ancient ocean floor and injected with plutons — analogous, and equally as complex, to the present-day Himalayas.
The now-levelled mountain chain stretches as far south as northern Alabama in the U.S., to Newfoundland, Nova Scotia, Prince Edward Island, New Brunswick and southern Quebec.
Within its accreted terranes lay a plethora of base and precious metal deposits, such as epithermal and orogenic gold mineralization along the many structural corridors, and polymetallic volcanogenic massive sulphides (VMS) that once peppered the seafloor of Iapetus.
The Appalachian Orogen relative to the other geological regions of Canada. Credit: The Canadian Encyclopedia.
Geological domains of the Appalachian Orogen. Blue represents ancestral North America, purple and yellow represent remnants of the Iapetus ocean and green are fragments of the North Africa Craton. Credit: after Hibbard et al. 2006.
Newfoundland
The island of Newfoundland forms the northeastern extension of North America’s Appalachian mountain range, retaining fragments of North Africa in the east, the Canadian Shield in the west and slabs of oceanic rocks in-between.
The most significant base metal district is the Buchans VMS camp in west-central Newfoundland. The cluster of world-class deposits saw 16.2 million tonnes produced of 14.5% zinc, 7.6% lead, 1.3% copper, 1.4 grams gold per tonne and 126 grams silver per tonne between 1927 and 1983.
A drill rig at El Nino Ventures and Votorantim Metals’ Murray Brook joint-venture polymetallic project in Nova Scotia. Credit: El Nino Ventures.
Next to Buchans is a northeast-trending belt of similar volcanic rocks that define the Victoria Lake VMS camp, where Teck Resources (TSX: TCK.B; NYSE: TCK) operated its Duck Pond copper-zinc underground mine before exhausting reserves and closing its doors last year.
When production began in 2007, measured and indicated resources at Duck Pond stood at 3.5 million tonnes of 4% copper, 7.1% zinc and 1.01 grams gold. Inferred resources added 1.1 million tonnes of 3% copper, 7.1% zinc and 0.81 gram gold.
Another VMS camp surrounds the northcentral town of Baie Verte, where Rambler Metals and Mining (TSXV: RAB) is mining its Ming copper-gold deposit. The underground mine has total proven and probable reserves (diluted and recovered) of 8.7 million tonnes at 1.8% copper and 0.52 gram gold for a total of 348.1 million lb. copper and 145,300 oz. gold.
The geology of Newfoundland and location of companies mentioned. Credit: Newfoundland Department of Mines and Energy, Geological Survey of Newfoundland and Labrador.
Baie Verte is also known for its gold occurrences. Although the yellow metal is largely mined as a by-product in VMS operations in eastern Canada, Anaconda Mining (TSX: ANX; US-OTC: ANXGF) is proving to be the exception at its Point Rousse project, 6 km northeast of Baie Verte.
The junior has been mining and exploring the structurally controlled and disseminated orogenic gold deposit since 2011. The deposit has 1.6 million indicated tonnes of 1.67 grams gold for 83,690 oz. gold and 208,700 inferred tonnes of 1.57 grams gold for 10,570 oz. gold, assuming a 0.7 gram gold cut-off.
Rambler Metals and Mining’s Ming copper-gold in north-central Newfoundland. Credit: Rambler Metals and Mining.
On another crustal-scale structure, 60 km south of the Buchans camp, Marathon Gold (TSX: MOZ) has outlined four near-surface gold deposits at its Valentine Lake project, with total measured and indicated resources of 15 million tonnes at 2.2 grams gold for 1.1 million oz. gold. Inferred resources add 2.2 million tonnes of 2.85 grams gold for 200,000 oz. gold.
Another 100 km southwest of Valentine Lake, First Mining Finance (TSXV: FF) is working to renew the historic Hope Brook underground gold mine on the south coast of Newfoundland. The deposit has indicated resources of 5.5 million tonnes at 4.77 grams gold for 844,000 oz. gold, and inferred resources of 840,000 tonnes at 4.11 grams gold for 110,000 oz. gold, using a 3 gram gold cut-off.
Other exploration projects across the island include Altius Minerals’ (TSX: ALS) Moosehead gold project, Benton Resources (TSXV: BEX) and Metals Creek Resources’ (TSXV: MEK) Staghorn gold project, Puddle Pond Resources’ Heritage gold-silver project and Minco PLC’s Lucky Strike copper-lead-zinc project.
Labrador
The geology of Labrador is much older than Newfoundland, with rocks dating back to 4 billion years — some of the oldest on earth. Labrador is part of the much larger Canadian Shield that extends into Quebec, Ontario, the Northwest Territories and Nunavut.
Exploration in Labrador has mostly focused on three areas: the Labrador Trough in western Labrador, the Central Mineral Belt near the region’s midline on the eastern coast and around Vale’s (NYSE: VALE) world-class Voisey’s Bay nickel-copper-cobalt deposit in the north.
The Labrador Trough is a 1,100 km long Proterozoic-aged sedimentary basin, toting more than 80 billion tonnes of iron ore resources. Due to deteriorating iron ore prices in recent years, many projects in the region have been placed on hold. The producers that remain include Iron Ore Co. of Canada at its Carol Lake operation, and Tata Minerals Canada at its direct-shipping ore project.
The Central Mineral Belt hosts much of the uranium mineralization in Labrador, and is also known for copper, molybdenum and rare earth metals. The most notable deposit is Aurora Energy Resources’ Michelin deposit, which hosts 15.6 million tonnes of 0.1% uranium oxide (U3O8) for 50 million lb. U3O8 as measured and indicated, and another 8.8 million tonnes of 0.1% U3O8 for 22.9 million lb. U3O8 as inferred.
The area around the Voisey’s Bay mine, 35 km southwest of Nain, serves as a hot spot for magmatic nickel-copper and platinum group metals exploration. Since entering production in 2005, Voisey’s Bay produced 382,800 tonnes copper and 548,000 tonnes nickel. As of December last year, the deposit has proven and probable reserves of 36.1 million tonnes at 1.1% copper and 2.2% nickel.
A few explorers in Voisey’s Bay camp include Commander Resources (TSXV: CMD), Fjordland Exploration (TSXV: FEX) and Equitas Resources (TSXV: EQT).
Simplified geology and metal districts of Labrador. Credit: The Geological Survey of Newfoundland and Labrador.
Nova Scotia
The same rock belt that makes up much of Newfoundland’s eastern and central zones also extends into northern Nova Scotia, and forms what’s known as the Avalon terrane. Vestiges of potentially VMS-rich oceanic crust in Newfoundland also occur across Cape Breton Island, but the area remains largely underexplored.
The only genuine example of VMS is the Stirling deposit in southeast Cape Breton Island. Also known as the Mindamar mine, the deposit produced 1.2 million tonnes of 6.4% zinc, 1.5% lead, 0.7% copper, 62.3 grams silver and 0.85 gram gold from intermittent operations between 1905 and 1956.
Cape Breton is home to carbonate-hosted, lead-zinc deposits — mineralization from the chemical reaction between hydrocarbons and metal-rich, subsurface brines. One example includes Merrex Gold’s (TSXV: MXI) Jubilee lead-zinc-barite deposit, which hosts an inferred resource of 3.1 million tonnes grading 4.7% zinc.
Bedrock terrane map of Nova Scotia and location of companies mentioned. Credit: Keppie (2000).
Similar lead-zinc deposits extend into the Gays River area of central Nova Scotia, where ScoZinc Mining (TSXV: SZM) is working to restart operations at its Scotia mine. The deposit, formerly known as Gays River, was mined intermittently since 1979, but was forced closed in 2009 when zinc and lead prices collapsed. Scotia hosts measured and indicated resources of 7.9 million tonnes at 3.3% zinc and 1.7% lead, and an inferred resource of 3.7 million tonnes at 2.4% zinc and 1.5% lead.
Sometime during the Appalachian orogeny, the Avalon terrane sutured against the Meguma terrane, a unique package of deformed sedimentary rocks plugged with intrusives.
Meguma is endowed with orogenic, vein and disseminated gold mineralization in two predominant camps: Western Meguma in the south, and Eastern Meguma along the region’s midline on its eastern coast.
Nova Scotia doesn’t have any active gold mines, but it has 10 advanced gold properties, nine of which have National Instrument 43-101 compliant resources. The gold inventory in the province, from existing resource estimates, totals 1.8 million oz. gold as measured and indicated, and 2.5 million oz. gold as inferred.
Projects include the former producing Dufferin gold mine, which poured its first gold bar in July 2014, but was placed on care and maintenance the following October due to equipment problems. As a result, the operating company, Ressources Appalaches, went into receivership.
Atlantic Gold’s (TSX: SVU) fully permitted Touquoy gold project, 110 km from Halifax, is showing promise as the next up-and-coming gold mine in the region. The low-grade, bulk-tonnage deposit has measured and indicated resources of 10.1 million tonnes at 1.5 grams gold for 480,000 oz. gold, using a 0.5 gram gold cut-off. Inferred resources add 1.6 million tonnes of 1.5 grams gold for 77,000 oz. gold.
The company also holds the Beaver Dam gold project, 37 km from Touquoy, which has measured and indicated resources of 9.3 million tonnes at 1.43 grams gold for 426,600 oz. gold, and inferred resources of 1.8 million tonnes at 1.37 grams gold for 81,300 oz. gold. Beaver Dam is being developed as a satellite deposit to the planned Touquoy operation, and permitting is underway.
Other advanced gold projects in the region include NSGold’s (TSXV: NSX) Mooseland and Orex Exploration’s (TSXV: OX) Goldboro.
New Brunswick
The world-class Bathurst VMS camp in northeast New Brunswick is the province’s flagship metal and mining district, having generated over $27.5 billion from zinc production for over half a century. The camp hosts 45 VMS deposits, similar in genesis and style to those seen elsewhere across eastern Canada.
Most historical production came from Glencore’s (LSE: GLEN) Brunswick No. 12 mine, one of the world’s largest underground zinc deposits, which produced 136.6 million tonnes of 8.7% zinc, 3.4% lead, 0.4% copper and 102 grams silver between 1964 and 2013.
The only active mine left is Trevali Mining’s (TSX: TV; US-OTC: TREVF) Caribou polymetallic mine and mill complex, 25 km northwest of Brunswick No. 12. The company declared commercial production in July and expects to deliver up to 41 million lb. zinc and 15 million lb. lead in payable metals by year-end.
Measured and indicated resources for the project stand at 7.2 million tonnes of 6.99% zinc, 2.9% lead, 0.4% copper, 84.4 grams silver and 0.89 gram gold. Inferred resources add 3.7 million tonnes of 6.95% zinc, 2.8% lead, 0.3% copper, 78.3 grams silver and 1.23 grams gold.
Geology and metallogenic map of New Brunswick. Credit: New Brunswick Department of Natural Resources, Minerals and Energy division.
Explorers with advanced-stage, base metal projects elsewhere in the district include Stratabound Minerals (TSXV: SB) at its Taylor Brook, Commander and Captain properties, and El Nino Ventures (TSXV: ELN; US-OTC: ELNOF) and Votorantim Metals at their Murray Brook joint-venture project.
The complexity of volcanic arc and continental plate interactions during the Appalachian orogeny generated a variety of structurally controlled, intrusion-related depositional environments in New Brunswick.
Early exploration targeted tungsten-molybdenum and tin-indium-zinc mineralization in the province’s southwest. The region is known for the Fire Tower molybdenum-tungsten deposit at Adex Mining’s (TSXV: ADE) Mount Pleasant property, which produced 2,000 tonnes of 70% tungsten concentrate between 1983 and 1985. Resources at the deposit stand at 13.5 million indicated tonnes of 0.3% tungsten, 0.2% molybdenum and 841,700 inferred tonnes of 0.3% tungsten and 0.2% molybdenum.
Similar tungsten-molybdenum mineralization styles also occur in west-central New Brunswick at Northcliff Resources’ (TSE: NCF) Sisson Brook deposit, which hosts proven and probable reserves of 334.4 million tonnes of 0.1% tungsten and 0.02% molybdenum. The company is seeking federal environmental approvals to develop the deposit into an open-pit operation with a 27-year mine life.
Many of the gold occurrences in New Brunswick are either directly or indirectly related to magmatism that occurred during the Appalachian orogeny. The intrusives assimilated metal-rich crust during their ascent and redirected the fluids along a number of structural corridors, such as the Annidale gold belt in southern New Brunswick.
The belt is a 70 km long, northeast-trending suture zone that hosts 26 known gold and base metal showings, including Wolfden Resources’ (TSXV: WLF) Clarence Stream deposit, which has 822,000 indicated tonnes of 6.9 grams gold for 182,000 oz. gold, and 1.2 million inferred tonnes of 6.34 grams gold for 250,000 oz. gold, assuming a 3 gram gold cut-off.
An outstanding geological summary, well done! Thank you.