Adeline Geology
Deposit Type
Stratiform sediment-hosted copper (SSC) deposits worldwide rank second only to porphyry copper deposits in copper production. SSC deposits are associated with evolving regional/ basin-scale fluid-flow systems and are typically hosted within intracontinental rift-related sedimentary sequences. Generally, the basin-derived fluids circulate through an oxidised (red-bed), aeolian to evaporitic assemblage, overlain by a reduced shallow marine transgression, accumulation of shales, carbonates or evaporites. The connate oxidised fluids circulating during basin evolution leach out the copper from, in the Seal Lake group, most likely source is the basalt flows of the Salmon Lake Formation, and precipitate in the more reduced grey bed facies. The ore deposits generally are zoned, usually to a district scale and characterised by barren/hematite – native copper – chalcocite – bornite – chalcopyrite – Pb/Zn/Co sulfides – pyrite. Zonation within the Adeline project is present on a local scale at various showings.
The formation of major SSC deposits (White Pine in Michigan, Kupferschiefer in Central Europe, Central African Copper Belt) coincides with periods of supercontinent amalgamation such as Rodinia in the Neoproterozoic and Pangea in the Permian-Triassic (Laurence Robb, Introduction to ore-forming processes, 2005).
Both the geological setting and the style of copper mineralisation suggest a favourable environment for hosting significant sediment-hosted stratiform copper deposits.
Adeline Project Geology
The Adeline project is located in Central Labrador at the triple junction of the Churchill, Grenville and Nain Province, within the Central Mineral Belt (CMB). The CMB is 260 km long belt hosting hundreds of copper, uranium, silver, REE and molybdenum showings. The western part of the CMB is dominated by copper showings, whereas the eastern part demonstrates globally significant uranium occurrences.
The Adeline project covers the youngest middle Mesoproterozoic volcano-sedimentary sequences, known as the Seal Lake Group, comprising the Central Mineral Belt. The Seal Lake Group consists of supracrustal argillaceous and arenaceous sedimentary rocks, intercalated with basalt flows and intruded by gabbro sills. The volcano-sedimentary rocks formed as a result of extensive continental sedimentation from the transition from subaerial to shallow-marine during a rift-related cycle of uplift and erosions.
Structurally, the group is a thrust contact with the Paleoproterozoic granitoids of the Trans-Labrador batholith. Immense structural deformation resulted in stratigraphic repetition of the sequences and complexly folded the group into an east-trending, doubly plunging syncline that is 120 km long and 45 km wide. The southern limb of the syncline has been overturned and thrust northward during Grenvillian deformation (ca. 1.0 Ga). The western side of the syncline exhibits more intense deformation with tighter folds than the eastern side (Altius, Seal Lake Copper Project Technical Report, 2015; T.S. van Nostrand, Geology of the Seal Lake area, 2010).
The rocks comprising the Seal Lake Group have been subdivided into six stratigraphic formations, from oldest to youngest: Bessie Lake – Majoqua Lake formations, Wuchusk Lake, Whiskey Lake, Salmon Lake, Adeline Island and the Upper Red Quartzite formations.
Mineralisation
Documented copper mineralisation occurs, mostly in the Salmon Lake and Adeline Island Formation. Host rocks to the mineralisation include shale, slate, basalt and gabbro of the Salmon Lake Formation, and slate, shale, phyllite, sandstone and gabbro of the Adeline Island Formation.
Copper mineralisation is epigenetic and likely attributed to deformation associated with the Grenville Orogeny. Mineralisation is mostly related to local shear zones, along foliation and/or within quartz +/- carbonate veins and is greatly influenced by the oxidation state of the various rock types (oxidised vs reduced)(Altius, Seal Lake Copper Project Technical Report, 2015). The mineralisation occurs in two distinctive styles:
- As fine-grained bedding, foliation and cleavage parallel dissemination nucleates into stratiform lenses in the grey, green to black shales. As well as chalcocite ± bornite ± chalcopyrite stringers and quartz-carbonate veins in diabase, basalt, in the grey, green to black shales, arenite and phyllite (reduced “grey beds”). Mainly present in the Adeline Island Formation. The grey bed hosted mineralisation is the primary target of our exploration.
- Native copper-bearing quartz-carbonate veins within the red slate and/or strongly hematized basalt units of the Salmon Lake, Whiskey Lake and Wuschusk Lake formations
Copper mineralisation styles identified through our 2021 Field program
Grey Bed Hosted
- Disseminated
Strongly foliated grey shales/slates with mineralisation either transposed into fabric or emplaced parallel to fabric and then modified. The mineralisation consists predominantly of malachite ±azurite after disseminated bornite ±disseminated chalcocite and minor chalcopyrite. (Ex: S. Adeline Mountain –South (left) Whiskey Lake 64 (right))
- Within veins
Strongly foliated grey shales/slates with mineralisation hosted within or along boundaries of quartz veins that can be boudinaged within regional foliation. The mineralisation consists predominantly of malachite ±azurite after being disseminated to locally massive bornite ±disseminated chalcocite. (Ex: Adeline Island and South Adeline Mountain)
Mafic Vulcanic Hosted
Mineralisation is predominantly in quartz-carbonate veins in foliated basalts and controlled site by jointing and/or foliation. Copper is present as native copper and locally in malachite and bornite minerals.
(EX: Whisky Lake 150 and Salmon Lake Main)
Grey Quartzite Hosted
Host rocks are weakly foliated grey quartzites in close proximity to contact with grey shales/slates. Mineralisation is associated with foliated zones near-contact of quartzite or disseminated within the host quartzite matrix with no direct foliation control. (Ex: Ellis Main and Adeline Island)
Target Areas
Priority Target areas visited during the 2021 Field program:
13 Major targets Identified:
Ellis Prospect
The Ellis Main prospect is exposed in a series of 11 trenches along a steep cliff face south of the western end of Seal Lake. Chalcocite-bornite occurs in association with quartz-carbonate veining within grey phyllite-slate of the Adeline Island Formation. The strongest mineralization occurs across a width of approximately 3-4 m (Altius, Seal Lake Copper Project Technical Report, 2015).
Individual historic grab samples:
- 4.88% Cu and 192 g/t Ag (Altius 2015)
- 4.02% Cu and 90.7 g/t Ag (Altius 2015)
- 3.92% Cu and 166 g/t Ag (Altius 2015)
- 3.54% Cu and 87.1 g/t Ag
Historic Drill intersections:
- From 90.6m intercept: 7.9m @ 1.76% Cu and 56.2 g/t Ag (Playfair hole SL-11-10)
- From 57.6m intercept: 4.3m @ 1.69% Cu & 51.8 g/t Ag and from 66.5m intercept 2.1m @ 1.66% Cu & 45.6 g/t Ag (Kennco hole K-10)
- From 92.4m intercept: 0.9m @ 1.08% Cu & 19.2 g/t Ag (Kennco hole K-12)
As part of our 2021 Field Program 21 rock chip samples were taken along 5 different lines, approximately totaling a sample length of 24 meters.
Adeline Island Prospect
Individual historic grab samples:
- 5.33% Cu and 55.6 g/t Ag (Altius 2015)
- 2.63% Cu and 24.2 g/t Ag (Altius 2015)
- 1.87% Cu and 22.6 g/t Ag (Altius 2015)
Historic trench samples:
- 1m @ 1.11% Cu and 12.1 g/t Ag (Altius 2015)
- 0.5m @ 5.22% Cu and 64.8 g/t Ag (Altius 2015)
- 1m @ 1.38% Cu and 32.5 g/t Ag (Altius 2015)
Historic Drill intersections:
- From 14.8m, intercept: 3.5m @ 1.85% Cu and 8.2 g/t Ag and from 25.9m intercept of 0.5m @ 1.23% Cu & 9.3 g/t Ag (Kennco K-3)
- From 2.7m intercept: 2.4m @ 2.45% Cu & 11.0 g/t Ag and from 16.5m intercept: 2.6m @ 1.09% Cu & 5.5 g/t Ag (Kennco K-1)
- From 18.6m intercept: 1.0m @ 1.32% Cu & 1.20g/t Ag and from 26.6m intercept 1.6m @ 4.70% Cu & 42.2 g/t Ag and 38.25-39.01m 0.8m @ 1.61%Cu and 17.1 g/t Ag (Kennco K-6)
- From 30.1m intercept: 0.3m @ 0.64% Cu & 7.74 g/t Ag and from 34.1m intercept: 0.5m @ 3.07% Cu & 26.5 g/t Ag (Playfair SL-11-02)
- From 18.0m intercept: 0.5m @ 2.40% Cu & 24.9 g/t Ag and from 26.9m intercept: 7.75m @ 0.52% Cu & 6.64 g/t Ag and from 38.3m intercept 0.70m @ 1.22% Cu & 6.51 g/t Ag (Playfair SL-11-08)
As part of our 2021 Field Program 27 rock chip samples were taken along 8 different lines, approximately totaling a sample length of 53 meters.
South Adeline Mountain Prospect
The occurrence is located on a north facing cliff on the south side of a small lake. The top of the ridge is fine grained, massive, homogeneous gabbro sill. Sitting stratigraphically below the gabbro and exposed along the steep cliff face are a sequence of grey shale that is at least 5 m thick. At the contact between the shale and gabbro there is a 20-30 cm wide hornfelsed zone with quartz-carbonate veins and blebby to locally 2-3 cm wide veins of bornite and chalcocite. The mineralized zone can be traced along strike for approximately 30 m. The vein appears brecciated in places with sulphide mineralization forming the matrix to the breccia (Altius, Seal Lake Copper Project Technical Report, 2015).
Individual historic grab samples:
- 13.55% Cu and 199 g/t Ag (Altius 2015)
- 9.28% Cu and 122 g/t Ag (Altius 2015)
- 9.09% Cu and 122 g/t Ag (Altius 2015)
Historic Drill intersections:
- From 0.6m, intercept: 6.1m @ 0.14% Cu and 3.1 g/t Ag (Kennco K-13)
- From 45.7m, intercept: 1.2m @ 0.19% Cu and 0.7 g/t Ag (Kennco K-15)
As part of our 2021 Field Program 11 rock chip samples were taken along 2 different lines, approximately totaling a sample length of 15 meters.