Zinc Lead Copper Silver Gold

Virtual Museum ID: 19-BCGS-FOR-06

Specimen Summary


Sphalerite is the main ore mineral for zinc, and although relatively common, finding it in commercial amounts is somewhat rarer. The zinc will give the mineral a yellow or red hue, but iron can replace the zinc in the atomic structure, making the crystals black. Rarely, cobalt finds its way into the structure, and produces green crystals. Although sphalerite is a relatively soft mineral, it can be cut (faceted) into attractive gems, which are used for mineral displays.

Galena is the main ore mineral for lead. Because of its relatively low melting temperature it can be easily smelted and has been used as a source of lead since ancient times. Galena has a cubic crystal system and can often be found as cubes or octahedra. Its shiny grey metallic lustre and heavy, dense nature make it easy to recognize. Galena often contains small amounts of silver, which add to its economic value.

Native Copper is a form of copper that occurs as a natural mineral. It is uncombined. Copper rarely occurs in a native form as it usually occurs mixed with other elements or in oxidized states. Most of the copper that is produced is extracted from sulfide deposits. It is metallic, has an opaque diaphaneity, is soft and has an isometric crystal system. Copper is used as a conductor of electricity, specifically as wiring. It is also a conductor of heat and used to make cooking utensils. Copper is used to make alloys as well.

Silver is an important precious metal. It is still highly valued today and has many important uses, as well as being used for jewellery. Silver has the highest electrical and thermal conductivity and reflectivity of all metals and is widely used in electronics and industrial chemistry. It is also used to make mirrors, photographic and x-ray film and collectible coins. Silver has natural antiseptic properties, therefore, has many different medical applications. Silver can occur in its elemental form as metallic silver, or in compounds and minerals with other elements like gold and lead. Silver has a distinct silver-grey colour and is soft and malleable, meaning it can be easily worked and shaped.

Gold is a valuable, highly prized mineral used in everything from jewellery to electronics and dentistry. Gold is desirable due to its special properties, such as malleability and resistance to tarnishing. Gold is commonly microscopic or embedded within or around sulphide grains. Free visible gold occurs as disseminated grains, or rarely as crystals. Crystals of gold commonly form within or around quartz. In its natural mineral form, gold is commonly alloyed with silver. Gold is distinguishable by its characteristic golden yellow colour and extreme heaviness.

Specimen Data

 

The information listed below relates to the current holding location or collection that the sample is from, and whether the item is viewable at that location or is part of a private collection. Coordinates are given as guides, and we remind you that collecting specimens from these locations is not allowed. Caution is advised visiting such sites and Below BC assumes no responsibility for any injuries or trespassing charges that may occur as a result of the viewer entering these sites.

Collection Details

Original Collection:

British Columbia Geological Survey (BCGS)

Sub Collection:

-

Collection ID:

FOR-06

Virtual Museum ID:

19-BCGS-FOR-06

Accessibility:

Date Added to VM:

2019-05-07

Location Information

Sample Origin:

SSW of Mt Edziza, B.C.

Specific Site:

Foremore Property

UTM Easting:

380889

UTM Northing:

6327171

Datum:

09 (NAD 83)

Coordinate Accuracy:

Specimen Details

VM Category:

Ore Sample

Primary Features:

Zinc Lead Copper Silver Gold

Primary Mineral Formula:

Zn · Pb · Cu · Ag · Au

Primary Category:

native element

Secondary Features:

Advanced Geological Information

 

The following section provides geological data relating to the specimen or the site it was collected from, when available. Information has been obtained from various sources including private and government datasets but may not be up to date. Any geological time periods or ages listed often relate to the primary geology of the area, and may not be the actual date of an event such as mineral formation.

Geological Formation:

Stikine Assemblage

Geological Period:

Devono-Mississippian

Stratigraphic Age:

419.2 - 323.2 Ma

Geological Belt:

Intermontane

Geological Terrane:

Intermontane

Minfile ID:

104G 148, 181

Site Details:

The North zone of the Foremore property is predominantly underlain by the Devono-Mississippian Stikine Assemblage, a suite of variably foliated mafic to felsic flows and volcaniclastics, interbedded limestone, and fine clastic sediments.

The North showing was located by Cominco Ltd personnel in 1989. In 1989 a geologic grid was established over the North Zone. Mapping and prospecting located finely laminated galena and sphalerite in felsic (quartz eye) volcanics and pyrite within the volcanics and graphitic/carbonaceous argillaceous phyllites. Outcrop sampling in the North Zone averaged 0.087 gram per tonne gold, 8 grams per tonne silver, 0.1 per cent copper, 0.3 per cent lead and 2.7 per cent zinc over an average sample width of 0.4 metre (Assessment Report 19379).

Along strike 1.25 kilometres to the northeast is the BRT showing (discovered in 2003) consisting of massive sulphides up to 3 metres in thickness exposed in a small creek at surface. Mineralization consists of semi-layered massive sphalerite, galena, pyrite, and lesser chalcopyrite in a quartz-rich gangue. The BRT showing and the North showing are interpreted to be part of the same stratigraphic interval. Both showings are hosted in pyritic quartz-sericite phyllites and schists within a larger thickness of northeast striking, southeast dipping chloritic, hematitic and carbonaceous phyllites.

Work History

In 1987, during helicopter reconnaissance in the headwaters of a south-flowing tributary of More Creek and Mess Creek, Cominco Ltd identified sulphide and gold rich mineralized boulders representing a variety of mineralized types. Between 1987 and 1992, and in 1996, Cominco spent over $2 million on geophysical, geochemical, geological and diamond drilling programs. Due to the location of many mineralized boulders at the north and south termini of the More Glacier, Cominco focussed their attention on searching up-ice (i.e. underneath the ice). Cominco allowed the property to lapse in 1999 and it was staked by Lorne Warren. Warren completed a program of prospecting and silt sampling in 2000. Rota Mines Inc. optioned the Foremore property in May 2002 and contracted Equity Engineering Ltd. to carry out a program of mapping, prospecting and geochemical sampling.

In 2002, Roca Mines optioned the Foremore Property and staked additional mineral claims. The 2002, the field program of Roca Mines consisted of prospecting, geological mapping, and soil and rock sampling. Work was focussed on searching the areas upslope from the known mineralized boulder fields, as well as other mineralized zones delineated by the previous Cominco work. The rocks samples collected were both reconnaissance in nature, and were taken over known mineralized areas.

In 2003, Roca Mines Inc. continued work on its Foremore property targeting gold and volcanogenic massive sulphide deposits. Eleven diamond-drill holes were completed totaling 1031 metres.

In 2004, Roca conducted prospecting, geophysics and a 37-hole drill program focused along a 3.5 kilometre length of folded Devono-Mississippian volcanic and sedimentary rocks in the North zone that contains the BRT showing. The thickest intercept was in drill hole FM04-04 where 3.1 meters averaged 14.6 grams per tonne gold, 1114 grams per tonne silver, 0.2 per cent copper, 1.2 per cent lead and 6.6 per cent zinc (Exploration and Mining in BC 2004 page 30). The mineral horizon, represented by pyritic phyllite near the contact between felsic and overlying mafic volcanic rocks, was traced 1.6 km north and tested with holes spaced 200 to 400 meters apart. Several holes encountered multiple layers of massive sulphide, each 0.3 to 1.2 meters thick, over a 300-meter interval within the felsic sequence. Visible gold was noted in FM04-32 in a 0.8 meter-wide sulphide band and assayed 26.5 grams per tonne gold, 85 grams per tonne silver, 2.2 per cent copper, 1.3 per cent lead, 8.6 per cent zinc (Exploration and Mining in BC 2004 page 30).

In 2005, Roca cored 4 drill holes totalling 2,033 metres and completed geological mapping, rock and soil sampling surveys. In August a 700 line kilometre helicopter supported airborne magnetometer and electromagnetic survey was flown over 50 per cent of the Property. The integration of new and historic data into the MapInfo platform was initiated. Three holes totalling 2033 metres were drilled along near the Ryder showing (new MINFILE), intersecting significant intervals of low grade sphalerite and chalcopyrite mineralization. Airborne geophysics (magnetics and electro-magnetics) was flown covering the present extents of the North Zone, as well as other mineralized areas. The Ryder showing is about 3 kilometers north east of the North showing (104G 148).

In late August 2006, the Property was flown for orthophotography.

In 2007, Roca carried out a detailed mapping program in the Hanging Valley. A total of 149 rock and 231 soil samples were submitted for chemical analysis (Assessment Report 29475). Mineralized areas discussed include SG (104G 181), Antler, Zig Zag, Boulder and Heather. At least one sample was taken in the SG area.

In 2008, Roca conducted a program included gridding in four areas totalling 78.0 line kilometres. A total of 52.6 line kilometres of Induced Polarization (IP) surveys and 57.7 line kilometres of Total Field Ground Magnetometer surveys were completed. In addition, 3,299.4 metres of drilling was completed in 13 holes from which 890 samples were submitted for analytical work. During the course of geological mapping a total of 301 rock and 197 soil samples were submitted for chemical analysis. Mapping occurred in several areas including the HV/SBF, Roca Flats, Ryder, Westmore and Antler areas. One bedrock grab sample (926005) of heterolithic felsic agglomerate located 500 metres west of the SG showing yielded 0.75 per cent copper (Assessment Report 30246). Holes were drilled into the HV, SBF, Ryder, BRT and Westmore. No drilling was completed in the Antler area.

The Westmore drilling of 2008 was in that area known as the North zone, and designated in MINFILE as Foremore (104G 148). The Ryder showing (new to MINFILE in 2013) is about 3 kilometres northeast of the MINFILE plot for North zone and about 6.5 kilometres northeast of Westmore (104G 184).

Field work during 2011 by Roca consisted prospecting and geochemical sampling. This work concentrated on the hillside around the SG zone, a gold-rich volcanic hosted massive sulphide showing. The 2011 work involved collecting 818 soil samples at 25 metres spacing along the northwest slope of the hanging valley in an attempt to locate the source to the South Boulder Field an area comprised of sulphide-rich boulders and blocks that carry base and precious metal mineralization. Dispersion patterns of elements in soil indicated a large anomalous area below the SG showing and down slope from the Sunday showing.

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