The Fireweed occurrence is located on the south side of Babine Lake, approximately 5 kilometres southeast of Smithers Landing, 54 kilometres northeast of Smithers.
In the occurrence area, Upper Triassic to Lower Jurassic Takla Group volcanic rocks, predominantly augite feldspar flows, outcrop along the west shore of Babine Lake south of the west arm. Maroon to green tuffs, sandstones, siltstones and shales of the Lower to Middle Jurassic Hazelton Group are exposed north, east and west of Babine Lake. Middle Jurassic to Upper Cretaceous marine to nonmarine clastic sediments, the Bowser Lake and Skeena groups (Kitsuns Creek Formation), are found adjacent to the Hazelton Group on the north shore and east and west of Babine Lake. Eocene Babine Intrusive plugs outcrop northwest and southeast of the property (Geological Survey of Canada Open File 2322).
An extensive blanket of glaciolacustrine-lacustrine clay, as thick as 40 metres, covers 95 per cent of the Fireweed property area. The oldest rocks known on the property are Hazelton Group volcanics. The volcanics are commonly fine grained, maroon to green andesitic to dacitic tuffs and lapilli tuffs. Interbedded mudstones, siltstones and sandstones of a thick deltaic sequence appears to underlie much of the area and are thought to belong to the Kitsuns Creek Formation of the Lower Cretaceous Skeena Group. The sediments commonly strike 070 to 080 degrees and dip subvertically. Locally, the strike varies to 020-030 degrees at the discovery outcrop, the MN showing. Several diamond-drill holes have intersected sills of strongly altered feldspar porphyritic latite.
Skeena Group sediments are dominantly encountered in diamond drilling. The sediments are dark and medium to light grey and vary from mudstone and siltstone to fine and coarse-grained sandstone. Bedding can be massive, of variable thickness, changing gradually or abruptly to finely laminated. Bedding features such as rip-up clasts, load casts and crossbedding are common. The beds are cut by numerous faults, many of them strongly graphitic. Drilling indicates Skeena Group sediments are in fault contact with Hazelton Group volcanic rocks. Strongly sericitized and carbonatized latite dikes cut the sediments.
Mineralization generally occurs in one of three forms: 1) breccia zones are fractured or brecciated sediments infilled with fine to coarse grained, massive pyrite-pyrrhotite and lesser amounts of sphalerite, chalcopyrite and galena; 2) disseminated sulphides occur as fine to very fine grains which are lithologically controlled within coarser grained sandstones, and comprise pyrite, marcasite, sphalerite, galena and minor tetrahedrite which are usually found interstitial to the sand grains; and, 3) massive sulphides, which are fine grained, commonly banded, containing rounded quartz-eyes and fine sedimentary fragments that occur as distinct bands within fine-grained sediments. The massive sulphides generally contain alternating bands of pyrite/pyrrhotite and sphalerite/galena. They are associated with the breccia zones and are commonly sandwiched between altered quartz latite dikes.
Alteration in the sediments occurs in the groundmass and appears associated with the porous, coarse sandstones. Common secondary minerals are quartz, ankerite, sericite, chlorite and kaolinite.
Three main zones have been identified by geophysics (magnetics, induced polarization) and are named the West, East and South zones. Three other zones identified are the 1600, 3200 and Jan zones.
The West zone is defined by an east trending, horseshoe-shaped induced polarization conductor. The original outcrop discoveries, the MN and the Sphalerite showings, lie at the westerly end of each of the prongs of the horseshoe. Drilling has defined a mineralized area 300 metres long which is open along strike and depth. Mineralization has been found in Skeena Group sediments to 200 metres depth. The bulk of the mineralization is hosted by coarse sandstone, in two parallel southwest plunging shoots, which are 30 to 60 metres wide combined.
Canadian United Minerals acquired the Fireweed claims in 1987 and began aggressive development over the next two years. This work included preliminary geological mapping, soil geochemistry, magnetometer and EM surveys and over 14,000 metres of NQ diamond drilling. The surface showing of the pyritic sandstone in the West zone assayed 344.0 grams per tonne silver over 9 metres (Property File Placer Dome - Callahan, 1988) and one drillhole sample assayed 2098.4 grams per tonne silver, 8.9 per cent lead and 2.8 per cent zinc (Property File Placer Dome - Callahan, 1989). Indicated reserves for the West zone are 584,500 tonnes grading 341.77 grams per tonne silver, 2.22 per cent zinc and 1.34 per cent lead or, at a higher cut-off, 399,124 tonnes grading 456.2 grams per tonne silver, 1.62 per cent lead and 2.7 per cent zinc (George Cross News Letter No.66, 1989). Minnova Inc. optioned the property in 1990 and a year later conducted induced polarization and resistivity surveys.
A flat lying, funnel-shaped feeder zone near the eastern limits of the West zone covers an area 90 by 90 metres and extends to a depth of 75 metres, but does not outcrop. Sandstone and mudstone interfinger throughout this area. Pyrrhotite, pyrite, sphalerite and chalcopyrite occur as massive sulphide mineralization associated with breccia and veins which cement mudstone and sandstone fragments that are millimetres to several metres in size. These zones of mineralization grade into unbrecciated or weakly veined areas. The sulphide content is variable and there are two distinct generations of veining. One contains massive sphalerite, the other massive pyrite and pyrrhotite. The breccia veins cut sericitized latite dikes. The feeder zone also contains minor gold and copper values. A selected assay grades 124.1 grams per tonne silver, 7.25 per cent zinc, 3.32 per cent lead, 0.13 per cent copper and 0.8 gram per tonne gold across 6.2 metres (Exploration in British Columbia 1988, page B130).
The MN showing is hosted in fine to medium-grained sandstone with heavy manganese coating lying in the massive beds which dip subvertically with a local strike of 030 degrees. The sandstone is quartz-carbonate-sericite cemented. Minor pyrite, sphalerite and galena are associated with increased manganese content. Diamond-drill hole intersections returned assays of up to 68.6 grams per tonne silver, 3.5 per cent zinc, 0.6 per cent copper, 2 per cent lead and anomalous gold (George Cross Newsletter No. 37, 1988).
The Sphalerite showing is 300 metres to the north of the MN showing. Outcrop is characterized by a strong, rusty yellow stain with sphalerite stringers crosscutting mudstone and sandstone. Surface samples from this zone have assayed up to 20.24 grams per tonne silver and 24,511 parts per million (2.45 per cent) zinc (Property File Rimfire - Canadian United Minerals Inc., 1990).
The East zone has a strike length of at least 500 metres and a 40 metre thickness containing sulphide-cemented breccia and veining. This zone is 2.4 kilometres east along strike from the West zone. Mineralization is in the form of pyrite and pyrrhotite with lesser sphalerite and chalcopyrite. A diamond-drill hole intersection across 2.98 metres assayed 22.62 grams per tonne silver, 2.97 per cent zinc, 0.27 per cent copper and 0.47 gram per tonne gold (George Cross Newsletter No. 85, 1989).
The 1600 zone is 500 metres west of the MN showing (south prong of the horseshoe-shaped West zone) and consists of a number of parallel sulphide horizons up to 2 metres wide with a strike length of 600 metres. Three diamond-drill holes have tested the zone over a 150-metre strike with grades up to 3.26 grams per tonne gold, 269.3 grams per tonne silver, 11.1 per cent lead, 10.9 per cent zinc and 0.15 per cent copper over 4 metres (Property File Rimfire - Canadian United Minerals Inc., 1990).
The Jan zone is 1 kilometre west-northwest of the MN showing (north prong of the horseshoe-shaped West zone). The 3200 zone is 1 kilometre east of the West zone, and the South zone is 500 metres south-southeast of the 3200 zone.
There is no evidence of early historical exploration work on the Fireweed claims (prior to 1987), although coal had been reported from the area. Mineralized float was found in the area in 1987 by John Leask and partners who staked the original claims in July 1987.
In August 1987, an option agreement was reached between the owners and Canadian United Minerals Inc. (later called Mansfield Minerals Inc). In September 1987, the company commenced work programs that included geological mapping and evaluation, soil geochemistry, magnetometer, very low frequency electromagnetic (VLF-EM), and induced polarization (IP) surveys, backhoe trenching and drilling. In 1988 and 1989, under a joint venture agreement with Canadian United Minerals, Gunnar Gold Inc. funded considerable work including drilling. Published assessment reports indicate Canadian United collected 89 rock and 3451 soil samples and conducted 51.7 kilometres of IP and 263 kilometres of ground magnetic and 157 kilometres of VLF-EM surveying. They also excavated 160 metres in seven trenches. No indication of drilling is indicated in published assessment reports though subsequent assessment reports refer to previous drilling.
In 1991, Minnova Inc. (later called Inmet Mining Ltd.), optioned the property and completed an additional drilling program, substantially outside of the known deposits, before returning the property to the vendors. Assessment reports state that 1101.5 metres were drilled in seven NQ diamond-drill holes.
In 1999, diamond drilling was carried out on the Ger 2 claim of the Fireweed property by Cedar Capital Corp. and Mansfield Resources. Six holes were drilled for a total of 1250.91 metres. The objective of the program was to further test the 1600 zone, where encouraging results had been obtained by diamond drilling in 1989.
In 2004, Argentor Resources concluded an agreement with J. Leask and Partners (Mansfield Resources Inc.). In 2005, Argentor Resources staked additional claims to protect the original claims held by Mansfield Resources Inc. They then completed approximately 25 kilometres of grid, followed by a geophysical program. A 3D induced polarization survey was completed, totalling 29.5 kilometres across part of the property. The survey concentrated on the area between the East and West zones. The IP survey assisted in the spotting of new drillholes planned by Argentor Resources for the 2006 drill program. In 2006, Argentor Resources changed its name to Jantar Resources Ltd. In 2006, Jantar Resources Ltd. completed 937.5 metres in five NQ diamond-drill holes. Hole FW 06-4 was reported to require additional drilling to define the limits of mineralization to depth and laterally on strike. This hole probed the ‘vent zone’ on a north-south section through previous hole 88-51. It penetrated a mineralized zone containing several 'beds' and intercepts of stockwork and breccia with massive sulphide mineralization. The massive sulphide zones are evident within a 24.7-metre section between 102.0 and 126.7 metres.
In 2008, Mansfield Minerals Inc. was restructured, and the Fireweed property was transferred to Pachamama Minerals Ltd.
In 2010, Shamrock Enterprises Inc. entered into an option on the Fireweed property and conducted an eleven-hole drill program. Highlights of this program include drillhole FW 10-1, which returned 28.79 metres grading 4.64 per cent zinc, 2.27 per cent lead, 64.6 grams per tonne silver and 1.05 grams per tonne gold (Assessment Report 32156). In 2011, Shamrock Enterprises Inc. completed an eleven-hole drill program totaling 1561.7 metres. Highlights of this program include drillhole FW 11-4, which returned 15.1 metres of 444.4 grams per tonne silver, 1.3 per cent lead and 2.4 per cent zinc (Press Release - Shamrock Enterprises Inc., April 18, 2012).
In 2012, Regulus Resources Inc. obtained the Fireweed property in a merger with Pachamama Minerals Ltd.
In 2014, Shamrock Enterprises Inc. was in the planning stages of its summer 2014 work program and also working toward applying for a small mines permit (75,000 tonnes- per-year) for the West zone high grade silver-lead-zinc discovery, which may enable the company to generate cash flow from operations. The historical resource on Fireweed (640,000 tonnes grading 277 grams per tonne silver, 2.22 per cent lead and 1.34 per cent zinc, 1989) comprises 19 drillholes in the West zone, and is open to depth and along strike. Shamrock believes the additional 14 successful diamond-drill holes from the 2006, 2010 and 2011 drill programs may add to a revised resource calculation. Drilling completed by Shamrock during its two most recent drill programs was very successful in intercepting additional high grade silver-lead-zinc mineralization in 11 out of 22 drillholes completed. The main mineralized trend of the Fireweed property, which may consist of a number of fault zones, covers more than three kilometres of strike length, 50 to 100 metres of stratigraphy and 175 metres to 200-plus metres of dip extent (Press Release - Shamrock Enterprises Inc., April 10, 2014).
In 2016, Shamrock Enterprises Inc. completed five NQ-sized diamond-drill holes for a total of 946.9 metres. The drill program tested the South zone target defined by a broad magnetic response. Additionally, a geochemical base metal anomaly in the South zone area, consisting of historical localized float sampling, returned up to 479 grams per tonne silver, 2.6 grams per tonne gold, 0.28 per cent copper, 2.6 per cent zinc and 1.3 per cent lead. The drill program was designed to test across strike of the magnetic anomaly, as well as the north edge, targeting possible lithological contact zones, which are historically known to be a favourable host for exhalative-style sulphide mineralization (Press Release - Shamrock Enterprises Inc., January 31, 2017).