Misty copper-gold prospect, Old Hogem, Omineca Mining Division, British Columbia, Canadai

Regional Level Types
Misty copper-gold prospect	Deposit
Old Hogem	- not defined -
Omineca Mining Division	Mining Division
British Columbia	Province
Canada	Country

The Misty copper-gold prospect is located in the Swannell Ranges near the headwaters of Duckling Creek, about 9.5 kilometres north of Old Hogem, 166 kilometres north-west of Mackenzie, and 165 kilometres north-east of Smithers, British Columbia, in the Omineca Mining Division. It is geologically similar to the much larger Lorraine deposit, 4.5 kilometres to the south-southeast.
There is an extended description of the property on the British Columbia “Minfile” site, current to 2019, to which interested readers are referred. Relevant portions pertaining to geology are quoted below:
“Mineral occurrences comprising the Misty developed prospect occur within strongly foliated rocks of the Duckling Creek Syenite Complex. The complex is elongated in a northwesterly direction and contains both intrusive and migmatized rock units showing considerable compositional diversity. Three main rock types are recognized on the property: hornblende monzonite, syenite and pegmatite. These rock types show much variation in texture and are gradational from one to the other. The hornblende monzonite unit is the most common lithology, texturally grading from medium grained to pegmatitic and displaying moderate to intense foliation. The development of gneissic banding is very common. In some areas the monzonite shows evidence of magma cumulate differentiation with the development of mafic and ultramafic fractions. The syenite varies from fine grained to pegmatitic in texture and generally occurs as dikes crosscutting the hornblende monzonite. The pegmatite unit consists of feldspar (85 per cent) and hornblende (15 per cent) and predominantly occurs as dikes cutting the two other lithologies.
Mineralization comprises disseminated chalcopyrite, pyrite and bornite, with veinlets of chalcopyrite and pyrite common along the contact margins of crosscutting syenite dikes and orthoclase veins. Mineralization is hosted within a northwest trending, chloritized, K-feldspar altered, hornblende biotite gneiss. The best mineralization appears to occur in the more intensely foliated rocks showing chlorite and potassium feldspar alteration together with fracturing and faulting. Grain size is very fine. The fine grained, sugary grey K-feldspar alteration is the most receptive common host to mineralization as northwest-elongate pods parallel to the early foliation.”
There have been several radiometric dates published for intrusive rocks in the general area of the property. Garnett (1978) reported a K/Ar age of 175±5 Ma, for biotite from pyroxenite at the nearby Lorraine deposit. Ootes et al. (2020) wrote that “The south-southeast part of the study area [lying immediately north of the Misty prospect] is underlain by quartz-undersaturated rocks of the Duckling Creek suite . . . . South of the study area, Devine et al. (2014) identified three stages of the Duckling Creek suite and constrained the timing with U-Pb zircon ages: 1) biotite pyroxenite (ca. 182 to 178.5 Ma); 2) predominantly K-feldspar porphyritic syenite to monzonite (ca. 178.8 to 178.4 Ma); and 3) massive syenite and pegmatite (ca. 177 to 175 Ma).”
There are no mineral resources available for the Misty prospect that could be regarded as National Instrument 43-101 compliant. O’Keeffe and Shearer (1990), quoting Jones (1989), reported that “Rough reserves were calculated at 3 million tons grading 0.63% Cu.” Pilcher and McDougall (1976) had earlier listed a “possible” 3 million tons grading 0.6% Cu, referencing “El Paso staff”. Schroeter (1995) listed 3 million tonnes at 0.6% Cu. Note that there were no gold assays available for these resource calculations. No more recent estimates are available and it appears that the prospect is, as presently defined, of very limited size.
The Misty copper-gold prospect is included in the USGS compilation by Singer et al. (2008). References quoted in this report for the prospect are included in the present reference list. The information given by Singer et al. (2008) is incomplete.
Giles Peatfield comments on the minerals reported:
The following comments, derived from several reports, give some details of the various minerals reported from the Misty copper-gold prospect and immediately surrounding area. These comments are by no means exhaustive, as the rocks are complex.
Amphibole group: O’Keeffe and Shearer (1990) reported “hornblende”, as did Baxter and Devine (2007) in drill core logging.
Apatite: O’Keeffe and Shearer (1990) reported traces of apatite in thin sections.
Azurite: This appears to be less common than malachite, but has been reported by several workers.
Bornite: This is a relatively sparse copper mineral at Misty, reported as disseminated and on fractures by most workers.
Calcite: Baxter and Devine (2007) noted that thin calcite stringers were common in drill core.
Chalcocite: Reported by Warren (1961), Wilmot (1962), and by Baxter and Devine (2007), who noted it as rare in drill core.
Chalcopyrite: The principal mineral of economic interest, reported by all workers. It is generally remarked as being very fine grained.
Chlorite group: Chlorite was reported by O’Keeffe and Shearer (1990) and by Baxter and Devine (2007), with no specific information as to mineralogy.
Epidote: Baxter and Devine (2007) noted traces of epidote in several pieces of drill core.
Feldspar group: Orthoclase is common here, often as very large crystals. Baxter and Devine (2007) also reported plagioclase (“albite”) and “microcline”.
Fluorite: This was reported by O’Keeffe and Shearer (1990) and by Baxter and Devine (2007), in limited amounts.
Galena: O’Keeffe and Shearer (1990) described two rock samples as follows: “The two samples with greater than 1000 ppb Au are MD 89 R14 and MD 89 R15, which assayed 1670 ppb Au / 11.4 ppm Ag and 0.754 oz/t Au / 7100 ppm Ag respectively. MD 89 R15 was also analyzed for Pb and Zn and returned significant values of 6.7% Pb and 1.22% Zn.
These samples are both near each other in Misty One claim. MD 89 R14 consists of malachite and azurite stained gneiss with disseminated chalcopyrite, while MD 89 R15 consists of veinlets of pyrite, chalcopyrite, pyrrhotite and galena in quartz veinlets in sheared gneiss. The presence of galena in Sample MD 89 R15 is important as its presence has not been previously recorded on the property.” Of interest to me is the assay of 1.22% Zn, with no mention of sphalerite – one suspects it must be there, although field geologists often find it difficult to identify.
Garnet group: O’Keeffe and Shearer (1990) described a rock sample as “Gneissic mafic (hornblende rich) diorite? Intensely laced with contorted qtz-feldspar veining crossing gneissic fabric at various angles. Pink garnet patches and minor magnetite in vein material.” Baxter and Devine (2007) reported numerous examples of garnet, in some cases described as “honey yellow/brown”. Neither report has any specific data regarding garnet composition.
Hematite: Baxter and Devine (2007) noted numerous occurrences of hematite lined fractures in core logging.
Limonite: Although probably common, the only references are to “rusty” rocks, and “Fe-oxide stain”.
Magnetite: This is common, reported by most workers. In places it is a major constituent of the rock.
Malachite: This is common and conspicuous, reported by all workers.
Mica group: O’Keeffe and Shearer (1990) noted muscovite and biotite. Baxter and Devine (2007) added sericite to the list.
Pyrite: This is common, reported by all workers.
Pyroxene group: Baxter and Devine (2007) reported diopside, often as an alteration mineral. They also reported clinopyroxene as a component of pyroxenite. This rock type has not been reported in the immediate Misty area, but is part of the Duckling Creek Syenite Complex.
Pyrrhotite: See comment above for galena.
Quartz: See comment above for galena. Also, O’Keeffe and Shearer (1990) reported samples of quartz veins with “chalcedonic” texture.
Sphalerite?: See comment above for galena.
Titanite: O’Keeffe and Shearer (1990) reported “sphene” as an accessory in thin sections of several rock types.
Giles Peatfield comments on the rock types reported:
The rock types listed are taken from several reports. Early workers did not have the advantage of recent detailed work, especially that done at the nearby Lorraine property, and their reporting may be suspect. Recent reporting by Baxter and Devine (2007) has identified the prospect as within the Duckling Creek Syenite Complex, consisting of syenite, monzonite and pyroxenite, the last not noted at Misty. They have broken these general rock types into a large number of sub-units, mostly based on textural differences, e.g. gneiss, pegmatite, feldspar porphyry, inter allia. One interesting note is that Noel (1970) reported lamprophyre; this sounds very much like what Nixon and Peatfield (2003) mapped as pyroxenite at Lorraine.

Giles Peatfield
BASc. (Geological Engineering) University of British Columbia 1966.
PhD Queen's University at Kingston 1978.
Worked for Texas Gulf Sulphur / Texasgulf Inc. / Kidd Creek Mines - 1966 to 1985.
Vancouver based consultant 1985 to retirement in 2016

Other Databases

Link to British Columbia Minfile:	093N 001

Other Regions, Features and Areas containing this locality

References