The Mets occurrence is located 4.5 kilometres east-northeast of Metsantan Lake and 4.1 kilometres southeast of the AL (BV) occurrence (094E 099), approximately 300 kilometres north of Smithers. The occurrence lies within the Omineca-Cassiar Mountains in the west-central portion of the Toodoggone Gold Camp.
The Mets occurrence is situated within a Mesozoic volcanic arc assemblage which lies along the eastern margin of the Intermontane Belt, a northwest-trending belt of Paleozoic to Tertiary sediments, volcanics and intrusions bounded to the east by the Omineca Belt and to the west and southwest by the Sustut and Bowser basins. Permian Asitka Group crystalline limestones are the oldest rocks exposed in the region. They are commonly in thrust contact with Upper Triassic Takla Group andesite flows and pyroclastic rocks. Takla volcanics have been intruded by the granodiorite to quartz monzonite Black Lake Suite of Early Jurassic age and are in turn unconformably overlain by or faulted against Lower Jurassic calc-alkaline volcanics of the Toodoggone Formation (Hazelton Group).
The dominant structures in the area are steeply dipping faults which define a prominent regional northwest structural fabric trending 140 to 170 degrees. In turn, high angle, northeast-striking faults (approximately 060 degrees) appear to truncate and displace northwest-striking faults. Collectively these faults form a boundary for variably rotated and tilted blocks underlain by monoclinal strata.
The Mets occurrence consists of a tabular core of silicified rock in three separate but genetically linked zones; the A zone (and extension), the Footwall zone and the 400 South zone.
The Mets property is underlain by northwest trending volcanic units of the Metsantan Member and crosscut by major and minor fault systems. The main northwest fault is possibly correlative with the Cliff Creek structure at the Lawyers mine (094E 066), 14 kilometres to the southeast. A ring and radial fracture system converges on nearby Metsantan Mountain peak. The oldest unit of the Adoogacho Member is composed of potassium feldspar andesite characterized by an aphanitic to finely crystalline groundmass containing 1 to 4 millimetre potassium feldspar phenocrysts. This unit forms the footwall of the A zone. Overlying the potassium feldspar andesite and forming the hangingwall of the A zone, is a porphyritic dacite of the Metsantan Member. The dacite consists mainly of clear and colourless to white, 1 to 2 millimetre quartz phenocrysts in an aphanitic pink plagioclase groundmass. A red tuff is often intercalated with the dacite and appears as an aphanitic to very fine-grained, well-sorted unit. It is composed mainly of very fine sized strands of quartz and plagioclase. Generally, the tuff is massive but in rare instances it exhibits slight graded bedding with tops to the west. A lapilli tuff unit has also been recognized and consists of a fine-grained groundmass of quartz and plagioclase with elongate and block shaped lithic fragments 5 to 10 millimetres in size (Assessment Report 16692).
Alteration at the Mets deposit is typical of epithermal environments; an extensive outer propylitic (epidote, chlorite, rare pyrite), adjacent advanced argillic (sericite, kaolinite, dickite), and inner silicic (quartz +/- barite) zones on both the hangingwall and footwall. Propylitic alteration is the most common alteration on the property and proximal to the A zone. Hangingwall dacites exhibit moderate to intense alteration; intensity increases upwards towards the breccia system. The propylitic envelope consists of an assemblage of chlorite and epidote and to a minor extent, rare calcite, and pyrite. Bleaching and silicification of hangingwall dacites becomes evident within 5 to 20 metres of the breccia system after which alteration shifts to argillic, evidenced by the deterioration of the plagioclase component of the dacite. Adjacent to the breccia zone is an interval of advanced argillic alteration comprising of an assemblage of clay minerals, primarily dickite, and kaolinite and sericite. Argillic alteration occurs in both the hangingwall and footwall side of the breccia system but primarily within the footwall side where the alteration envelope can range from 1 to 40 metres in thickness. Alteration of the footwall potassium feldspar andesite is minimal and is restricted to argillic alteration of brecciated andesites and to a lesser extent, propylitic alteration. Silicification of the breccia material is extensive and can be found throughout the breccia or at times as a silicified wall, bounding both the footwall and hangingwall sides of the breccia system. Generally, it is within the silicified intervals where the better grade gold mineralization occurs.
Locally, a quartz-barite breccia occurs near the vertical contact between the potassium feldspar andesite and porphyritic dacite and is the host for gold mineralization in the A zone. The breccia generally occurs at the andesite/dacite contact but in some instances will cross both units. The breccia consists of microbrecciated to coarse (10 centimetre) fragments of quartz, barite and porphyritic dacite. Fragments have been re-brecciated and cemented with quartz and barite; at least three brecciation cycles have been noted. Quartz character ranges from chalcedonic to coarsely crystalline, white to grey in colour. Barite usually occurs as white to pink, fine-bladed crystals. Native gold is the primary ore mineral present with rare occurrences of electrum, argentite, tetrahedrite, pyrite, and galena. Gold occurs as free grains and flakes (0.005-2 millimetres) adjacent to fragments of quartz and barite within the breccia system.
The A zone has a strike length of 140 metres, a true thickness of 6 to 10 metres and vertical extent of up to 75 metres. It strikes 340 degrees with 70 to 85 degree dips to the west. An ore shoot within the A zone has a gentle northwest plunge. Gold mineralization occurs as free blebs and grains ranging from 0.005 to 2.000 millimetres. Gold is generally found along quartz and barite fragment margins. Sulphide mineralization is practically nonexistent (Assessment Report 16692).
The most apparent geological feature which controls gold grades within the A zone is attitude and thickness of the breccia. Steep, thin breccias generally are of economic grade; when breccia orientation flattens, such as at depth, ore grade drops off rapidly. At the north end of the zone, a crosscutting vertical fault (N75 fault), terminates ore-grade material.
Localized flat, vertical, and block faulting provides for minor displacements of the A zone. Striking skew to the A zone at 290 degrees is the Red fault with approximately 35 metres of left lateral displacement. The A zone is truncated by the N75 fault, a vertical graben structure striking 050 degrees and dipping 80 degrees south with the north block down dropped with up to 100 to 110 metres of vertical displacement.
Deep drilling (1987) north of the N75 fault intersected a quartz breccia (N75 zone or A Extension) at a vertical hangingwall-footwall contact. The breccia occurs over a narrow width (4 metres) with gold grades ranging from 0.85 gram per tonne across 4 metres to 22.834 grams per tonne across 7.1 metres (Assessment Report 16692). The N75 zone suggests vertical movement on the N75 fault of approximately 100 metres.
Trenching has exposed the Footwall zone, a quartz-carbonate breccia situated within footwall potassium feldspar andesites. The footwall breccia has been exposed at three points over a 260-metre strike length. The breccia has a large carbonate content and the metal ratios are Ag:Au = 2:1 or greater versus Au:Ag = 10:1 or greater for the A zone. A one-metre channel sample assayed 19.81 grams per tonne gold and 127.86 grams per tonne silver (Assessment Report 16692). The Footwall zone is interpreted to strike 340 degrees with an indeterminate dip. Widths of the breccia pinches and swells with a maximum width on surface of 4 metres. A drill intersection assayed 19.29 grams per tonne gold over 0.7 metre (Assessment Report 16692).
Drilling (1987) has also intersected the 400 South zone, a narrow quartz breccia hosting gold mineralization at the potassium feldspar andesite/dacite contact. One intersection, in drillhole M87-42, graded 4.11 grams per tonne over 1.6 metres (Assessment Report 16692). Drillhole M87-31 intersected 1.0 metre grading 8.03 grams per tonne gold (Assessment Report 16692).
Historic geological reserves for the A zone are 143,321 tonnes grading 11.31 grams per tonne gold (Assessment Report 16692). Historic inferred resources for the combined Footwall and N75 zones are 317,485 tonnes grading 11.31 grams per tonne gold (Property File - M.E.G. Talk, November 18, 1987).
A later evaluation of reserves indicated roughly half of the previously reported reserves. Re-assessment of previous drilling outlined a cut and diluted mineable (probable and possible) reserve of 54,068 tonnes grading 11.66 grams per tonne gold (Northern Miner - September 1992).
The Mets deposit, located 15 kilometres northwest of the Lawyers (Cheni) mine (094E 066), was found by Golden Rule Resources Ltd. in 1980. The property hosts several quartz-barite breccia zones characteristic of epithermal systems. The Mets 1-2 claims (40 units) were staked early in 1980 for Golden Rule Resources Ltd. The company began a program of geochemical soil and silt sampling and prospecting which located several anomalies. Work in 1982 and 1983 included geological mapping, geochemical and geophysical surveys, and trenching. No work was done on the property in 1984.
In 1985, a subsidiary company, Manson Creek Resources Ltd. optioned the property and work in 1985-86 included geochemical surveys, extensive backhoe trenching, and 1882 metres of diamond drilling in 24 holes on the A zone. This work was reported to have outlined 83,444 tonnes grading 11.31 grams per tonne gold (Northern Miner - March 9, 1987, page B11).
Assessment Report 25707 reports that from 1985 to 1988 Golden Rule defined a geological resource of 143,760 tonnes grading 11.31 grams per tonne gold.
An agreement was reached in 1992 between Cheni Gold Mines Inc. and Golden Rule Resources Ltd. and Manson Creek Resources Ltd. to develop and mine the Mets deposit. An initial phase of underground evaluation was completed by September 1992, reducing the reserve to 54,068 tonnes grading 11.66 grams per tonne gold (Northern Miner – September 1992; Property File Document 676781). After considering these results, together with the projected development, mining and processing costs, and low gold prices at the time, Cheni Gold Mines Inc. decided not to pursue mining the Mets deposit in 1993 (Property File Document 676781). The property was subsequently returned to Golden Rule.
AGC Americas Gold Corporation and joint venture Antares Mining and Exploration Corporation conducted 18.5 kilometres of induced polarization surveys on the AL and Mets properties in late fall to early winter of 1997 (Assessment Report 25707).
