British Columbia Ministry of Energy, Mines and Natural Gas and Responsible for Housing
News | The Premier Online | Ministries & Organizations | Job Opportunities | Main Index

MINFILE Home page  ARIS Home page  MINFILE Search page  Property File Search
Help Help
File Created: 24-Jul-1985 by BC Geological Survey (BCGS)
Last Edit:  31-Mar-2021 by Garry J. Payie (GJP)

Summary Help Help

NMI 094D3 Cu2
Name MAGNUM, D, A, B Mining Division Omineca
BCGS Map 094D025
Status Prospect NTS Map 094D03E
Latitude 056º 13' 35'' UTM 09 (NAD 83)
Longitude 127º 02' 31'' Northing 6233001
Easting 621396
Commodities Copper, Lead, Silver Deposit Types D03 : Volcanic redbed Cu
L01 : Subvolcanic Cu-Ag-Au (As-Sb)
Tectonic Belt Intermontane Terrane Stikine
Capsule Geology

The Magnum occurrence, located on the D showing, is approximately 3 kilometres northwest of Mount Patcha (Property File - Mouritsen, S. A., 1969). The B showing is 1 kilometre to the west and the A showing is 1 kilometre to the north of the D showing.

The showings are hosted in Lower Jurassic Telkwa Formation (Hazelton Group) argillaceous tuffs, volcanic flows, argillites, and andesitic pyroclastics. Intruding these rocks are diorite dikes, which are possibly related to and contemporaneous with the Eocene Kastberg Intrusions (Property File - Mouritsen, S.A., 1969).

Faulting in the area generally trends west to north-northwest and has resulted in numerous fractures within the country rocks. A large west-striking fault runs through the middle of the property and is informally named the "main fault". Alteration is most pervasive near the main fault and is mainly chloritization and silicification.

The A showing consists of bornite and chalcopyrite with minor pyrite and galena, in heavily fractured and malachite-stained volcanic tuffs.

The B showing is located 14.5 kilometres west of Bear Lake at an elevation of 1710 to 1766 metres. It consists of a zone of malachite-staining along the border of a quartz feldspar porphyry stock.

The D showing is located 12.8 kilometres west of Bear Lake. The mineralized zone is 90 metres wide by 270 metres long and consisted of bornite and minor chalcopyrite hosted in malachite-stained fractures and veins. The fractures and veins are associated with the main fault.

The main showing was discovered in 1963 by Northern Exploration Limited but details of the drilling of 12 holes were reported on in 1970 by S.A. Mouritsen. An assay from the B showing returned 377 grams per tonne silver and samples from blasted surface cuts of the D showing averaged 1.84 per cent copper and 32.9 grams per tonne silver over 8.23 metres. Twelve, 15-metre drill holes were completed and returned an "arithmetic average" of 7.13 grams per tonne silver and 0.383 per cent copper (Property File: Cyprus Anvil; Bear Lake Project report for Roosevelt Mnes Ltd., by S.A. Mouritsen, 1970).

Eight of 12, 1964 drill holes were located by Electrum Resources in 2007 as were a number of blast pits and old trenches, some of which were sampled. A veinlet of botryoidal chalcocite was noted in one trench. At surface the main (primary) copper sulphide is bornite. Centimetre-sized blebs of bornite were noted at one locality as were malachite and chalcocite. Electrum's 2008 report indicated that MINFILE showings Magnum (094D 058) and Copper (094D 120) were likely to be shear-related copper showings that had been locally upgraded by supergene processes. The known mineralization is mainly in faults and scattered veins, and the highest grades recorded appeared to be close to surface. Electrum stated that no bodies of mineralization are known to have grades and dimensions sufficient to indicate economic potential.

WORK HISTORY

In 1963/1964 work (at least in part) by Northern Exploration Limited and in 1969/1970 by Roosevelt Exploration Ltd, on the Magnum showing (094D 058) and the Copper showing (094D 120) consisted of sampling, mapping and drilling. Several showings were investigated, and at D prospect (094D 058) a detailed look at fault related mineralization was made. Pits were blasted and 12 drill holes in a rough grid pattern were placed across a mineralized area some 274.3 metres long and from 91.4 to 137.1 metres wide. Exploration on the Copper showing (094D-120) yielded 88 chip samples and 1 DDH hole near a mineralized 175 metres (horizontal) and within 30 metres of the fault zone returned 24.86 grams per tonne silver and 0.27 per cent copper (Property File - Mouritsen, S.A., 1970, page 8). The centre of the zone was tested with a shallow 18.3 metre drill hole which returned 21.36 grams per tonne and 0.561 per cent copper over the total length (Property File - Mouritsen, S.A., 1970, page 8).

An IP survey was carried out for 97837 Resources Company in 1984. No geological data were provided, but a showing was reported to be located near Tarn Lake (Assessment Report 11837). The survey covered parts of Electrum's 2007 claims 555997 and 531529 and over and north of the plotted MINFILE location for Magnum (094D 058), about 700 metres south of Patcha lake. The geophysical survey indicated “...a readily discernible anomaly, some 500 by 300 metres in area, is outlined by the 10-millisecond contour". Similar results from an incomplete survey near Tarn Lake, just over 1 kilometre southwest of Patcha Lake, were also reported. A fault contact striking northwest through the corner of Patcha Lake is proposed on the basis of the geophysical response. The geophysical survey was conducted over and north of the location of MINFILE occurrence (094D 058).

In 2007, Electrum Resource Corporation held the PAT claim group of 3004 hectares in the vicinity of Mt Patcha, northwest of northern end of Bear Lake. The claims include four MINFILE showings; Magnum (094D 058), Pat (094D 071), Topo (094D 117), and Copper (094D 120), each contained within claims 555997, 531535, 555063 and 555062 respectively. One day was spent in the Magnum occurrence area where 10 rock and 10 soils samples were collected. One day was spent in the Topo occurrence area where 9 rock and 13 soil samples were collected. One day was spent in the Copper occurrence area where 4 rock samples, 1 soil sample and 3 stream sediment samples were collected. One day was spent in the Pat occurrence area where 19 rock, 2 soil ,1 talus fines and 1 stream sediment samples were collected.

Electrum Resource interpreted that vertical drilling was done in 1963 or 1964 rather than in 1969 or 1970 but reported that non-vertical drillholes found on site were of a later vintage. Mouritsen supervised the 1969 and 1970 work on Magnum and discusses the 12 drill holes in his report (dated 1970) but does not acknowledge when or who drilled them. Mouritsen states that considerable information was derived from Dr. J.F.V. Millar, (P.Eng) who supervised the 1963/1964 Magnum work. However, Mouritsen's 1970 report does shows that a diamond drill was air-lifted onto the property in 1969.

Bibliography
EMPR ASS RPT 11837, *30038, 34667
EMPR GEM 1970-186
EMPR OF 2001-18
EMPR PFD *16650 *810551
EMPR PF (*Mouritsen, S. A. (1969) Report on Bear Lake Project, Copper Magnum Groups for Roosevelt Mines Limited (not found in Property File search and is likely the report dated Oct.5, 1970) ; *Cyprus Anvil (Mouritsen, S.A. (October 5, 1970): Report on the Copper-Magnum Claim Groups Roosevelt Mines Ltd.))
EMR CORPFILE (Roosevelt Mines Ltd.)
GSC MAP 962A
GSC MEM 251
GSC OF 342
GSC P 76-29

COPYRIGHT | DISCLAIMER | PRIVACY | ACCESSIBILITY