On the TV zone of the Corey property, drilling by Kenrich Mining Corporation, resulted in the discovery of significant stratabound massive to semimassive gold-silver-zinc-lead mineralization (Hutchings horizon) in the TV (Tim/Val) zone.
Rock units were assigned to the Salmon River Formation felsic and mafic volcanic sequence with interbedded sediments. Rock types observed include amygdaloidal andesite or dacite, flow-banded feldspar-phyric dacite tuff, autobreccia and lapilli tuff and black mudstone. All units are strongly overprinted with orthoclase feldspar and sericite alteration (potassic alteration). Mineralization comprises pyrite, galena, arsenopyrite, with traces of sphalerite, ruby silver and possibly stibnite. Sulphides occur as disseminated grains, veinlets and colloform in-fillings in breccia, rhyolite and black mudstone.
Mineralization at the TV zone occurs in two environments. The riches zone is a locally discordant, pyritic, siliceous zone. This zone, up to 60 meters wide, trends northwest (330 degrees) and dips moderately (60 degrees) to the east. The zone occurs within an extensive package of hydrothermally altered rock. This auriferous zone is marked by moderate to intense silicification of volcanic and volcaniclastic rock and black mudstone. It is bounded by variably sericitized, carbonatized or silicified very fine grained brecciated basaltic andesite flows, lesser fine to medium grained massive basaltic andesite flows, assorted carbonaceous sediments and volcaniclastic sediment (of basaltic andesite composition). Pyrite is the dominant sulphide in this alteration zone. Pyrrhotite and sphalerite are rare within the auriferous zone although common within the alteration zone where gold is absent.
The second environment hosting gold mineralization is within rocks of a sedimentary package. Here, gold values occur in the range of 1 to 2 grams per tonne (Assessment Report 24373). This mineralization is within black, weakly silicified and carbonatized mudstone. Pyrite, the main sulphide within the mudstone, occurs as massive lenses, stringers and beds (50% pyrite over widths of 1 to 2 meters). Much of the pyrite is conformable to bedding, however, some is definitely cross cutting and is likely remobilized. Gold values in this environment occur where pyrite is most abundant and likely contained within the pyrite. Individual pyrite beds and stringers within mudstone range from 1 to 15 cm in thickness. For the most part, these drill holes outline Sedimentary horizons immediately east of the intense hydrothermal alteration of the TV zone.
In general, the silicified and sericitized alteration of the TV zone is considered to be a hydrothermal center which acted as a conduit for the flow of metal bearing fluids into a submarine basin within which base and precious metals were deposited. The greatest potential for an economic auriferous volcanogenic massive sulphide deposit lies in the pyritic mudstone and associated sediments.
The TV zone has been traced up to 1500 metres on strike with widths over 90 metres (Information Circular 1996-1, page 25). A 12.3-metre diamond drilling intersection assayed 2.07 grams per tonne gold and 120.3 grams per tonne silver (WWW http://www.kenrichmining.com), June 1998.
Work History
In 1993, Kenrich did a regional, mapping, geochemical and prospecting program over what is now referred to as the TV Zone. In 1994, Kenrich concentrated geological mapping and grid soil geochemistry and trenching over the TV Zone in preparation for drilling in 1995. They also did grid geochemisay and geophysics over the Bench and Battlement Zones. In 1995, Kenrich drilled 22 diamond drill holes totaling 3,863.63 metres over the TV Zone. They also did detailed geological mapping and soil geochemistry over this zone. In 1996, work over the TV Zone consisted of detailed geological and structural mapping of the area, soil geochemistry filling in holes in the coverage, 133 metres of surface trenching and 1559.44 metres of diamond drilling in a total of 11 drill holes.
In 1996, Kenrich drill tested the TV, Cumberland (104B 011) and Bench (104B 010) zones. In addition, an 1100-kilometre airborne magnetic and radiometric was completed. The TV zone was extensively re-mapped and drilling located a new silver-rich (pyrargarite) portion hosted by black shales, extending the zone to the north and east. The company estimated (non 43-101 compliant) the mineral inventory of the TV zone at approximately 3920 kilograms of gold and 111,000 kilograms of silver (Information Circular 1997-1, page 29).
In 2020, Eskay Mining Corp. completed a program of prospecting, rock sampling, ground and airborne geophysical surveys and 4335 metres of diamond drilling in 20 holes on the area as part of the Sib-Corey-North Mitchell property. The geophysical surveys consisted of a 911.7 line-kilometre airborne electromagnetic survey, a 55.85 line-kilometre induced polarization survey and a 43.19 line-kilometre magnetotelluric survey. Drilling was performed on the TV and Jeff (MINFILE 104B 525) occurrences. Massive sulphide, up to 6 metres in width, was discovered in multiple holes at the TV zone, defining a new lower zone of mineralization yielding greater than 1 gram per tonne gold and up to 500 grams per tonne silver including 3.18 grams per tonne gold and 25.7 grams per tonne silver over 29.92 metres in hole TV20-40 (Lindsay, D., Prowse, N.D. [2021-06-08]: NI 43-101 Technical Report on the Sib-Corey-North Mitchell Property).
