Pillow basalt

Virtual Museum ID: 19-DV15

Specimen Summary


Basalt is a mafic commonly extrusive(volcanic) but locally intrusive(e.g. dikes or igneous rock formed from the rapid cooling of magnesium-rich and iron-rich lava. Composed largely of plagioclase feldspar and pyroxene.

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:

Drifter Ventures Ltd. (DV)

Sub Collection:

-

Collection ID:

DV-15

Virtual Museum ID:

19-DV15

Accessibility:

Date Added to VM:

2019-08-15

Location Information

Sample Origin:

American Creek

Specific Site:

-

UTM Easting:

474702

UTM Northing:

6160522

Datum:

09 (NAD 83)

Coordinate Accuracy:

Specimen Details

VM Category:

Rock

Primary Features:

Pillow basalt

Primary Mineral Formula:

-

Primary Category:

-

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:

Stuhini Group

Geological Period:

Upper Triassic

Stratigraphic Age:

145 to 163.5 Million Years Ago

Geological Belt:

Intermontane

Geological Terrane:

Bowser Lake

Minfile ID:

103P 223

Site Details:

The Ajax occurrence is located on the east slope of Mount McGuire, about 13 kilometres northeast of the town of Alice Arm. Newmont Exploration defined considerable reserves of molybdenum from extensive drilling carried out during the 1960s.

The deposit is a result of the intrusion of four closely-spaced stocks into a folded sequence of Upper Triassic Stuhini Group sediments. The area is underlain by argillite, siltstone and greywacke with a few augite andesite flows up to a metre thick. These rocks occur on the steeply dipping east limb of the northwest trending Mount McGuire anticline. They have been contact metamorphosed in a north-northwest trending 2100 by 1500 metre zone centred on the four stocks. The inner part of this zone consists of quartz-albite-epidote-garnet skarn alteration, while the outer portion consists of biotite hornfels.

The stocks are small, elongate quartz monzonite bodies of the Eocene Alice Arm Plutonic Suite covering a 900 by 750 metre area. The southern stock trends northwest with dimensions of 460 by 300 metres, the other three stocks trend east-northeast with dimensions of about 300 by 150 metres. The two southern stocks are quartz-feldspar porphyritic quartz monzonite and the two northern stocks are essentially a network of closely spaced east-northeast and north-northwest trending dikes of biotite-rich quartz monzonite.

Alteration is most common in the two southern stocks and consists of the sericitization of plagioclase phenocrysts and the alteration of biotite to muscovite. Silicification occurs adjacent to quartz veinlets.

Mineralization occurs within the stocks and in the adjacent contact metamorphosed rocks as randomly orientated fractures filled with quartz and pyrrhotite and coatings and bands of molybdenite. Disseminated molybdenite also occurs in a stockwork of 3 to 6 millimetre diameter quartz veinlets and in silicified zones deeper within the stocks.

Four stages of mineralization are evident in the Ajax deposit. An initial stage of quartz-pyrrhotite mineralization is followed by two stages of quartz-molybdenite-pyrrhotite mineralization. These are followed by a final stage of coarse grained quartz veins, up to 7 centimetres wide, containing sphalerite and lesser amounts of pyrite, galena and chalcopyrite. The Le Roy occurrence (103P 163) is one of the largest of these veins.

Combined (measured and indicated) reserves at Ajax are 178,540,000 tonnes grading 0.07 per cent molybdenum; grade given was 0.121 per cent MoS2, conversion to Mo using a factor of 1.6681; total reserves of 417.3 million tonnes grading 0.09 per cent MoS2 (or 0.05 percent Mo) (CIM Special Volume 15 (1976), Table 3, page 422).

The property area history is extensive where in 1926-27, Kitsault-Eagle Silver Mines Ltd. completed stripping and opencutting and a 30-metre drift on the Le Roy vein (103P 163). In the 1950s, Kenneco Exploration and Climax Molybdenum Limited explored the general area and although a gossan was observed from the air, it apparently was never investigated on the ground. In 1964, a prospector employed by Newmont Mining Corporation reviewed the data and proposed the area for staking. In 1965, Newmont Mining Corporation staked the Ajax property and conducted mapping that outlined the limits of the alteration zone. Twenty-five trenches were blasted and seven AX wireline drillholes totalling 1580 metres were completed. In 1966, Newmont conducted mapping, sampling and the drilling of 15 Nxwl/Bxwl sized holes totalling 4155 metres. In 1967-68, Nemont formed a joint venture with Canadian Nickel (Canico-Inco) and four BQ-AQ sized diamond-drill holes totalling 2365 metres drilled. Also in 1968, Canex Aerial Explorations Ltd. completed a data review and a reserve calculation. Between 1968 and 1980, Newmont Mining Corporation/Canico were owners and the property lay dormant. In 1980, thin section studies were completed by Newmont Mining Corporation/Canico. In 1981, additional thin section and alteration studies were conducted by Newmont Mining. Between 1981-89, Canico completed a minor report that states "…the conclusions of both the Newmont and Canico studies are that the Ajax deposit should not be considered as an operational possibility until such time as economics demonstrate that tonnages of materials grading less than 0.15 per cent MoS2 constitute ore…". In 1990, Great Northwest Resources, as part of its property review, collected 152 3-metre-long core samples from holes 67-1, 2 and 3 and assayed them for gold. In 1996, Tenajon Resources Corp. staked the Molly Queen #2 property to cover the Ajax deposit when the property was allowed to drop by the Newmont/Canico Joint Venture. In the same year, Tenajon Resources completed a preliminary prospecting program along the eastern flank of Mount McGuire and ten grab samples of outcrop and float peripheral to the main deposit collected. In 1997, Tenajon Resources sent 176 reject samples of drill core for gold analysis and 30 element inductively coupled plasma analysis. In 2005, Tenajon Resources Corp. undertakes a detailed compilation of the data. In the same year they completed three diamond-drill holes totalling 1165 metres. The purpose of the program was to determine whether large diameter drill core and better drilling techniques would result in increased grade.

In August 2006, Tenajon Resources Corp. released mineral resource estimates for the Ajax deposit, containing an inferred resource of 345,070,000 tonnes grading 0.070 per cent molybdenum, above a cut-off grade of 0.04 per cent molybdenum (Resource World, Volume 4, Issue 7, page 43).

In 2007, Tenajon Resources Corp. released updated resource estimates which include 38.8 million tonnes indicated resources grading 0.064 per cent molybdenum and 448.8 million tonnes inferred resources grading 0.063 per cent molybdenum at a cut off of 0.040 per cent molybdenum (Stockwatch, June 21, 2007).

In May 2008, Tenajon Resources Corp. released updated resource estimates which include indicated resources of 69 million tonnes grading 0.065 per cent molybdenum and inferred resources of 483.12 million tonnes grading 0.061 per cent molybdenum at a cut off of 0.040 per cent molybdenum (Press Release - Tenajon Resources Corp., May 15, 2008; www.sedar.com).

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