The Nickel Mountain E&L deposit is in the headwaters of Snippaker Creek, 27 kilometres east-southeast (116 degrees) of the Bronson Creek airstrip and 300 kilometres northwest of Smithers.
The host rock gabbro and its related nickel-copper deposit were emplaced mid-Jurassic to mid-Cretaceous time and are therefore unrelated to the main Lower Jurassic and mid-Tertiary plutonic suites of the region. This suggests that the extensive Jurassic Bowser basin stratigraphy to the east is prospective terrain for similar deposits.
The deposit consists of pyrrhotite, pentlandite and chalcopyrite hosted in an olivine gabbro stock that intrudes Lower Jurassic sediments and volcanics. Exploration has identified 2.9 million tonnes grading 0.80 per cent nickel and 0.62 per cent copper with anomalous values in gold, silver, and platinum group elements (Quartermain, R.A., 1987; Sharp, W.M., 1968). Fieldwork by the Geological Survey Branch was completed in 1988 and 1989 as part of an ongoing regional mapping project in the Iskut-Sulphurets area.
The Nickel Mountain stock crops out at 1850 metres elevation along the crest of a steep ridge sloping south toward Snippaker Creek and continues northward as a series of razorback ridges around glaciers and snowfields. Regionally, strata trend northeast with gentle to moderate northwest dips. The Nickel Mountain gabbro intrudes a thick sedimentary and volcanic sequence of the Lower Jurassic Hazelton Group. A large monzodiorite pluton intrudes the volcano-sedimentary package 3 kilometres northwest of the deposit. Regional deformation postdates the pluton. Late post-deformation mafic dikes crosscut all rocks in the area.
Sedimentary strata hosting the mineralized gabbro stock are black laminated shales of the Lower to Middle Jurassic Salmon River Formation. The basal calcareous grit and fossiliferous limestone member of the Salmon River formation type section has not been identified in the Nickel Mountain area. A thick sequence of felsic to intermediate volcanics and thin interbedded sediments underlies the Salmon River Formation. The package consists primarily of dacitic ash tuffs and lapilli tuffs, commonly plagioclase porphyritic. Thin sedimentary units are distributed randomly throughout the volcanics. This volcanic sequence can be correlated with the Lower Jurassic Betty Creek Formation (Hancock, 1990).
The Nickel Mountain gabbro is a unique lithology in the Stewart-Iskut district. The gabbro intrusions consist of four small plugs less than 100 metres wide at surface, one large stock approximately 800 metres across and a dike swarm approximately 250 metres wide, all occurring along a 3 kilometre northeast trend. The large stock and dike swarm may be connected as they are separated by a large ice-filled cirque. The stratigraphic and structural evidence suggests the intrusion of the gabbro postdates the Lower to Middle Jurassic sediments and predates the mid-Cretaceous deformation. This brackets the age of intrusion at 185 to 110 Ma.
A large pluton of porphyritic quartz-monzodiorite, the Jurassic Lehto porphyry, truncates sedimentary strata of the Salmon River Formation north and northwest of Nickel Mountain. The rock is typically medium to coarse grained with white plagioclase, pink potassium feldspar, grey quartz, black hornblende and lesser biotite. Medium-grained diorite dikes crosscut all other units in the area and are most probably Tertiary in age. They are typically rusty weathering, dark grey diorites 1 to 10 metres wide.
Regional deformation has been dated at approximately 110 Ma in the Stewart area (Alldrick, D.J. et al, 1987). At Nickel Mountain there is a general northeast-southwest shortening. Sediments have taken up most of the stress in open, cylindrical folds. Stereonet plots indicate one phase of folding with a fold axis of 15/305 and an axial plane of 126/80SW. Weak penetrative axial planar cleavage is present in the fine-grained sediments. Volcanic units are block faulted with individual blocks generally undeformed. Interbedded sediments show small scale folding. Tertiary northwest-southeast extension controlled intrusion of the diorite dikes.
Nickel and copper sulphide mineralization occurs exclusively within the central gabbro body. At surface there are three major mineralized zones. The Northwest and Southeast zones are the most significant; both are roughly triangular with dimensions of 60 by 45 by 45 metres. The East zone is considerably smaller and less continuously mineralized than the other two. Surface and underground drilling indicate an irregular pipe-like form, possibly interconnected to the three zones at depth (Jeffery, W.G., 1966). Structural data collected by Sumitomo Metal Mining Corporation indicate a steep southwest plunge to the mineralized pipes (Hirata, Y., 1972). Vertical extent of the mineralization has been proved to a depth of 210 metres and the zones remain open laterally and to depth.
Mineralization is localized along the margins of the intrusion as irregular pipelike zones of veins, disseminations and massive lenses. The mineral textures and spatial relationship of the sulphides to the gabbro indicate that the mineralization is magmatic. Pyrrhotite, pentlandite and chalcopyrite are the dominant sulphides with minor amounts of pyrite, magnetite and "siegenite". Nickel occurs predominantly in pentlandite, but it is also present in a secondary nickel sulphide with a composition between siegenite (Co,Ni)3S4, and violarite (Ni,Fe)3S4. Chalcopyrite shows minor supergene alteration where covellite locally forms rims around the chalcopyrite and occasionally completely replaces it. Trace amounts of cobalt, noted in assay results, probably occurs in both the pentlandite, replacing iron, and the siegenite (Cabri, L.J., 1966). Gabbro within and around mineralized zones shows extensive alteration; olivine grains are partially or totally altered to serpentine, most plagioclase is altered and abundant chlorite, amphibole, biotite, carbonate, epidote and prehnite occur throughout the matrix (Hirata, Y., 1972).
Alteration of the host sediments is limited to an aureole less than 20 metres wide, of intense bleaching to a light green colour and partial loss of textures. Previous mapping identified these thermally altered sediments as either chert, siliceous tuffs or metadiorite.
Work on the E & L claims has identified three zones of nickel-copper mineralization exposed at surface and three additional zones underground. Published reserves are presented in the following table:
___________________________________________________ Indicated and Inferred Reserves Category Tonnes Ni Cu Au Ag (000's) % % g/t g/t Trench and Drill Indicated 1734 0.80 0.62 0.34 6.8 Inferred 1194 0.80 0.62 0.34 6.8 (Exploration Summary, 1976; Quartermain, R.A., 1987; Sharp, W.M., 1968). ____________________________________________________ |
Platinum group element values ranging from less than 50 to 400 parts per billion platinum and from less than 5 to 415 parts per billion palladium were obtained from grab samples collected in trenches by Consolidated Silver Standard Mines Limited in 1986 (Quartermain, R.A., 1987) and Ministry geologists in 1988.
Initial shallow drilling in the Central zone in 2018, intersected visually strong nickel sulphide mineralization over significant widths to depths of 75 meters - deeper holes are planned. Three massive sulphide showings (Crevasse, Gully and Cliff) were identified in the Central zone, exposed by the retreating icefield, featuring a classic pyrrhotite-pentlandite-chalcopyrite mineral assemblage. By early December, 2018, multiple new massive sulphide showings, particularly in the Central Zone where mineralization is trending to the north beneath the 1.6 kilometre-long, 1-kilometre wide E&L ice sheet. Drilling and extensive surface work at the Nickel Mountain (E&L) deposit identified three relatively shallow zones (Discovery, Central, Northwest) including a newly identified sulphide body 30 meters above the Discovery Zone at a depth of just 80 meters. Each of the zones remains open in all directions and features top tier massive sulphide grades of an unusually pure composition. These new zone are adjacent to the immediate east and southeast of the historic E&L prospect, over a distance of about 275 metres.
2017 drilling at "Anomaly A" intersected the mafic gabbroic host rock with magmatic sulfide mineralization that are disseminated and massive (75 to 100 per cent sulfides). The disseminated sulfides are comprised of blebby to interstitial pyrrhotite, pentlandite and chalcopyrite predominantly contained within the taxitic textured olivine gabbronorite and olivine melagabbronorite of the E&L Intrusive Complex (Assessment Report 37934). 2018 drilling determined that gabbroic rocks of the E&L intrusion are typically melanocratic taxitic to orbicular-texted olivine gabbros. The E&L intrusion is a classic example of a differentiated gabbroic complex which has had successive pulses of silicate and sulfide magmas emplaced through a very efficient magma highway from the mantle demonstrated by the quality of massive sulphide mineralization, specifically well-developed granular pentlandite and minimal nickel in pyrrhotite (Assessment Report 38839).
WORK HISTORY
The E & L Nos. 1 & 2 claims were located on the showing in 1958 for the Bik Syndicate; the syndicate was financed by Silver Standard Mines Limited, Mclntyre-Porcupine Mines, Limited, and Kerr Addison Mines Limited. Geological mapping, geochemical sampling, hand trenching and packsack drilling were carried out. No further work was reported until the 1965 field season when the E & L Nos. 3 to 28 claims were located to protect the original two that cover the showings. On the upper part of the showings 122 metres of trenching was done and 7 x-ray holes were diamond-drilled totalling 107.28 metres.
The E & L claim Nos. 29 to 40 inclusive were located in 1966; the property then consisted of a single, approximately rectangular block of 50 claims. Work during the year included geochemical and magnetic surveys, trenching, and 380.37 metres of diamond drilling in 5 holes. Work to that date indicated a potential of 2476 tonnes per vertical foot averaging 0.80 per cent nickel and 0.62 per cent copper (Northern Miner December 4, 1969). Measured and Indicated reserves to a depth of 213.35 metres were estimated at 1,733,000 tonnes grading 0.80 per cent nickel and 0.62 per cent copper. The Bik Syndicate partners in February 1967 incorporated a new operating company Nickel Mountain Mines Ltd. Silver Standard Mines Limited held a 69 per cent interest, the remainder being held by Kerr Addison Mines Limited and McIntyre Porcupine Mines Limited.
Sumitomo Metal Mining Canada Ltd optioned the property in 1970. An exploration adit was driven some 380 metres vertically below the surface outcrop and 260 metres below the lowest intersection obtained in previous drilling. During 1970 and 1971 the adit was driven to a length of 450 metres. Underground diamond drilling totalling 2260 metres in 11 holes failed to intersect ore grade mineralization. A magnetic survey was carried out over 7 line-miles. Sumitomo relinquished its option in 1971.
Nickel Mountain Mines Ltd was dissolved in January 1976 and the property was transferred to a syndicate in which Silver Standard held a 93.5 per cent interest; the latter company name was changed in 1984 to Consolidated Silver Standard Mines Limited. In 1986 the property was re-examined in terms of its platinum potential; selected grab samples were analyzed. In 1987, ground magnetometer and airborne magnetic/VLF electromagnetic surveys were conducted by Western Geophysical Aero Data Ltd. to outline mineralization beneath the cirque to the northeast. In 1990, Lexington Resources Inc. optioned the property.
In 1990, a work program was carried out on the Nickel Mountain Property (E&L claims) by Lexington Resources Ltd. who held the claims under option from Silver Standard Resources Inc. The program consisted of 1 BQ diamond-drill hole totaling 135.3 metres and an airborne program consisting of 140 kilometres of magnetic and electromagnetic surveying.
The claims containing the E&L were still held by Silver Standard Resources Inc. in 2012 though no exploration activity is documented since 1990.
In 2016, Garibaldi Resources Corp collected channel and grab samples from in the Northwest, Central and Southeast zones near the top of Nickel Mountain. Grab sample yielded values as high as 4.6 per cent nickel and 2.0 per cent copper with average grades of 2.7 per cent nickel and 1.7 per cent copper (Garibaldi Resources, Press Release, October 14, 2016). Highlights from continuous channel sampling across the widest part of a 12-metre mineralized zone at E&L include: 12 metres at 1.6 per cent nickel and 1.57 per cent copper, including eight metres at 2.3 per cent nickel and 2.2 per cent copper (Garibaldi Resources Corp., Press Release, November 10, 2016).
In late 2016, Garibaldi Resources Corp reported that recent regional sampling of several sulphide and precious metal occurrences yielded exceptionally high zinc values and highly anomalous gold and copper at the new Brass Hill target (formerly called Colagh, (104B 352)) within Garibaldi Resources Corp.'s expanded E&L project. Brass Hill is 2.7 kilometres northeast of the E&L deposit. Garibaldi is now referring to Brass Hill as E&L East.
In 2017, Garibaldi Resources announced that a recently completed helicopter-borne versatile time-domain electromagnetic (VTEM) and magnetics survey over an area of 47km2 on the E&L property revealed multiple conductive anomalies with scale and signatures highly prospective for the discovery of new areas of nickel-copper-rich massive sulphide mineralization over a six kilometre strike length. The four most prominent anomalies were named A, B, C and D. The D anomaly coincides with the sulfide mineralization within the E&L Gabbro at Nickel Mountain and was the sole focus of the 2017 diamond drilling campaign (Garibaldi Resources Corp., Press Release, May 25, 2017; Assessment Report 37934).
Garibaldi further reported that fieldwork in 2017 at the company's E&L Project resulted in a new surface discovery following up on the first of four major VTEM conductor targets. Widespread pyrrhotite-chalcopyrite mineralization has been identified on surface in gabbroic rocks that outcrop over a broad area at previously unexplored "Anomaly A", approximately 6 kilometres north-northeast of the historic E&L nickel-copper-rich mineralized zones mineralization (Garibaldi Resources Corp., Press Release, July 27, 2017). Garibaldi further reported on July 27th that drilling was to commence shortly at the E&L project (Anomaly D) along with much more mapping and sampling at ‘Anomaly A’. Diamond drilling intersected a sequence of mafic and ultramafic rocks. Highlight results included 8.3 per cent nickel and 4.2 per cent copper over 16.75 metres (Exploration and Mining in BC 2018, pages 130, 138). There were many significant zones of disseminated sulfides encountered in thirteen of the fourteen drill holes - totalling 540.2m of intervals that composited greater than 1.0 per cent combined Ni-Cu values (Assessment Report 37934).
An airborne ‘versatile time-domain electromagnetic’ (VTEM) survey was flown over the E&L and PSP (Palm Springs) properties in early 2018 by Geotech Ltd. to expand upon previous survey results and provide detailed coverage over newly-identified prospective areas. In 2018, Garibaldi Resources Corp. carried out a 32 hole 11,573 metres diamond drilling program. Highlight results for 10 holes include 30.5 metres of 3.10 per cent nickel, 1.86 per cent copper, 0.081 per cent cobalt, 0.863 gram per tonne platinum, 1.776 grams per tonne palladium, 0.739 gram per tonne gold, 7.3 grams per tonne silver and 5.6 metres of 7.60 per cent nickel, 3.36 per cent copper, 0.198 per cent cobalt, 0.668 gram per tonne platinum, 0.814 gram per tonne palladium, 0.466 gram per tonne gold, 9.0 grams per tonne silver (Exploration and Mining in BC 2018, page 132 (Assessment Report 38839). To date, drilling and extensive surface work at the Nickel Mountain deposit has identified three relatively shallow zones (Discovery, Central, Northwest) including a newly identified sulphide body 30 metres above the Discovery Zone at a depth of just 80 metres (Press Release Garibaldi Resources, December 6, 2018).
In 2019, Garibaldi Resources continued drilling on the Lower and Upper Discovery zones. By September 2019, drillhole EL 19-53 had intersected the longest section of continuous mineralization (86.5 metres) east of the historic E&L deposit since Garibaldi discovered the high-grade Lower and Upper Discovery Zones in its first-ever drill program at Nickel Mountain in 2017. Results from 2019 drilling included expansion and thickening of the eastern section of the Lower Discovery Zone (LDZ) to the north as demonstrated by drill hole EL-19-82 which cut 9.83 metres of massive sulphides grading 7.2 per cent nickel, 3.6 per cent copper and 4.8 grams per tonne 3PM (precious metals palladium, platinum and gold combined) within 32.75 metres of 2.7 per cent Ni and 1.6 per cent Cu (135.25 to 168 metres). This hole also cut 5.97 metres of 4.3 per cent Ni, 2.3 per cent Cu and 1.5 grams per tonne 3PM in the Upper Discovery Zone (UDZ) (Press Release Garibaldi Resources, February 21, 2020).
The 2020 initial drill program tested a large conductor on the eastern side of the Lower Discovery Zone (LDZ), while the remainder of 2020 exploration focused along a highly prospective 2 kilomtre east-southeast trending corridor interpreted to be a significant magmatic pathway for the E&L Intrusion (Press Release Garibaldi Resources, June 26, 2020) In 2020 drill hole EL-20-96 produced an 18.5 metre interval including the lower section of the orbicular gabbro and top portion of the LDZ significantly enriched in palladium and platinum, grading 3.75 grams per tonne Pd, 1.86 gram per tonne Pt, and 1.58 grams per tonne Au. Notably, this hole intercepted a newly discovered semi-massive sulphide zone 450 metres east of the lower discovery zone (LDZ) at a depth of 645 metres. Expanded 2020 regional prospecting resulted in new surface discoveries, including outcropping mineralized gabbro at Mount Shirley 14 kilometres to the north-northeast of E&L. (Press Release Garibaldi Resources December 31, 2020).
