The Galaxy occurrence is situated at Galaxy Lake, approximately 8 kilometres west-southwest of Kamloops.
The Iron Mask Batholith, which hosts the occurrence, lies in the southern part of the Quesnel Trough, also known as the Nicola belt. Regionally, the oldest rocks are the Devonian to Permian Harper Ranch Group, composed of a lower volcanic arc succession and an upper carbonate platform succession. The Harper Ranch Group forms the basement of the Quesnel Terrane regionally.
The most important Pre-Tertiary rocks in this belt are Upper Triassic volcanic and sedimentary rocks of the Nicola Group. The batholith is subvolcanic and composed of multiple intrusions that are comagmatic and coeval with the Nicola rocks. It is situated along the southwest side of a regional northwest-trending fracture zone and is itself cut by numerous northwesterly faults. Broadly, the batholith is made up of two major northwest-trending plutons separated by 6 kilometres of Eocene Kamloops Group volcanic and sedimentary rocks that unconformably overlie the batholith. These Eocene rocks include tuffaceous sandstone, siltstone and shale with minor conglomerate, as well as basaltic to andesitic flows and agglomerates with minor dacite, latite and trachyte. The Tertiary rocks occupy what appears to be a graben structure resulting from renewed fault movement around the margins of the plutons during Paleocene or Early Eocene time (Bulletin 77).
The larger Iron Mask pluton is 18 kilometres long and lies to the south of the smaller Cherry Creek pluton, which outcrops farther northwest on either side of Kamloops Lake. The combined exposure of the batholith, including the intervening younger rocks, is approximately 33 kilometres long and 5 kilometres wide.
In the vicinity of the batholith, the Nicola Group is dominated by volcanic and volcaniclastic sedimentary rocks. They are generally recognized by the albitization of feldspars, the occurrence of patchy epidote, and/or rare hematite alteration. On the southwestern flank of the Iron Mask pluton, well indurated, massive and bedded tuff, breccia and interbedded flows and flow breccia are prominent and weakly metamorphosed. On the northeast flank, less well indurated and less altered tuff and tuff breccia predominate; however, adjacent to the intrusive contact, these rocks are also well indurated and epidotized and are locally mineralized with sulphides. At the southeastern tip of the Iron Mask pluton and locally along the southwestern flank, the Nicola rocks are distinctive porphyritic augite-hornblende basalt.
The Iron Mask pluton has been described as containing four major, successively emplaced units designated as the Iron Mask Hybrid, Pothook, Sugarloaf and Cherry Creek units. Locally, an additional Picrite unit also occurs, although it is probably not genetically related to the batholith. The smaller Cherry Creek pluton consists entirely of the Cherry Creek unit. Isotopic dates (194 to 204 Ma -±6 Ma) indicate that all units are of Late Triassic or Early Jurassic age (Bulletin 77).
The component units (excluding the Picrite unit) of the multiphase batholith are largely controlled by major systems of northwest-, north- and northeast-trending fractures or faults. Most units show some degree of alteration and/or contamination, which might be intense locally. Weak to moderate saussuritization is ubiquitous in all batholithic rocks, whereas potassium feldspathization is more prominent in rocks of the Cherry Creek unit.
The units are briefly described in order of oldest to youngest (determined mainly on crosscutting relationships). The Iron Mask Hybrid unit forms the spine of the Iron Mask pluton. It is mostly agmatitic, consisting of rounded to angular fragments of various sizes, texture and composition in a dioritic matrix. The fragments include mainly coarse- and fine-grained diorite and coarse-grained gabbro with lesser amounts of medium to coarse-grained hornblendite. The unit is generally representative of variable assimilation of Nicola Group rock by the Pothook and Sugarloaf phases. Though the abundance of Nicola Group xenoliths is variable, Nicola fragments can comprise up to 80 per cent of the rock within an intrusive breccia. All rock varieties in the unit contain magnetite, which is often more than 10 per cent by volume. Mineralization, particularly of iron and copper, is nearly ubiquitous in this unit. The former Iron Mask copper mine (MINFILE 092INE010) is located in this unit but is also associated with the Picrite unit.
The Pothook unit occurs mainly in the northwestern half of the Iron Mask pluton, appearing frequently as narrow, gradational zones between the Iron Mask Hybrid and Cherry Creek units. Rocks of this unit are uniformly of dioritic composition and are medium to coarse grained. The Pothook unit is locally mineralized with copper and iron.
The Picrite unit consists of rocks of basaltic composition with abundant clinopyroxene and serpentinized olivine phenocrysts. These rocks generally occur as steeply dipping, poorly exposed and relatively small lenticular bodies in many parts of the batholith. The Picrite unit and frequent associated copper mineralization appears to be associated with recurring, northwest-trending fracture systems. Because picrite basalt has been observed far from the two component plutons of the batholith, it is probable that this unit is not part of the batholith. The observed occurrence of picrite basalt far from the two component plutons suggests that this unit is not part of the batholith.
The Sugarloaf unit occurs mainly along the southwest side of the Iron Mask pluton and as small enclosed bodies in the southern half of the pluton. Rocks of this unit are mainly fine-grained, porphyritic hornblende diorite with hornblende, minor clinopyroxene and plagioclase in a greyish green matrix. They are of fairly uniform diorite-andesite composition. Several copper occurrences are hosted by the Sugarloaf rocks. The Ajax deposit (MINFILE 092INE012) east of Jacko Lake, for example, is located within brecciated and albitized Sugarloaf rocks. The Afton deposit (MINFILE 092INE023) is 9 kilometres west-northwest of the Galaxy zone; the Ajax deposit (MINFILE 092INE012) is 4 kilometres south-southeast.
The Cherry Creek unit is the most widely distributed phase of the batholith. It constitutes the entire Cherry Creek pluton. The unit is broadly a biotite monzonite to monzodiorite but also involves rocks with composition ranges from diorite, monzonite and syenite to their porphyritic and fine-grained equivalents as well as local intrusive breccias. Potassium feldspar alteration gives the unit a pink colour, and it is texturally similar to the Pothook phase. The age relation between the Cherry Creek and Sugarloaf phases is uncertain because they have only been seen in fault contact. Copper and minor iron mineralization is prominent in the Cherry Creek unit, particularly in zones of intense brecciation associated with alkali metasomatism. The Afton mine lies at the western termination of a narrow, 4-kilometre-long, easterly trending zone of intense intrusive brecciation that is located at the northern edge of the Iron Mask pluton. The brecciation is considered to have resulted from high-level venting events.
Locally, the Galaxy zone occurrence is a small, alkaline-type porphyry copper-gold deposit. The occurrence is hosted within a fault-bounded pendant composed mainly of dioritic phases of the Iron Mask Batholith and volcanic and sedimentary rocks of the Nicola Group. On the western margin of the property, a northwest-trending band of picrites occurs on the eastern side of a major, steeply-dipping and northwest-trending fault; on the western side of this fault, the Cherry Creek phase occurs. East of the picrite, Nicola volcanics, Sugarloaf and Hybrid phases occur above a highly foliated, hematitic red mylonite with a thickness on the order of metres. Mineralization mostly occurs within the Sugarloaf phase and Nicola volcanics in the hanging wall of this mylonitic thrust zone, believed to be part of the Cherry Creek thrust.
Mineralization consists of chalcopyrite, pyrite and pyrrhotite with local bornite as fracture fillings and veinlets and as very fine grained disseminations adjacent to fractures. Locally, veins of semimassive to massive chalcopyrite-pyrite-pyrrhotite exceed 1-metre widths. Only very minor oxidation of sulphides exists within the zone below 3 metres. Mineralization is generally best developed near the intersection of the northwest and northeast fault zones.
Workings on the Golden Star claim (Lot 845) in 1899 included open cuts, shallow shafts and a 26.2-metre-long adit. Workings on the Evening Star claim (Lot 1013) in 1899 included open cuts, pits and a short adit.
In 1900, the claim was Crown-granted to The Kamloops Copper Mining Company Limited. Between 1905 and 1906, a shaft was sunk to 27.4 metres and 6 metres of drifting were carried out at the 17-metre level.
In 1906, the Evening Star group consisted of three claims—the Evening Star, Golden Star and Bill Nye—and was owned by J.H. Morrison, A.S. McArthur and J.M. Harper. In 1912, the Evening Star claim was Crown-granted to J.H. Morrison, A.S. McArthur and J.M. Harper. By 1913, ownership of the adjoining Golden Star claim was transferred to McArthur and Harper.
The Granby Consolidated Mining, Smelting and Power Company Limited is reported to have optioned this and other nearby properties in 1916 and carried out prospecting and diamond drilling. In 1916 and 1917, 48 tonnes of ore was shipped at an average grade of 5.3 per cent copper and 18.8 grams per tonne gold (Assessment Report 29628).
No further activity was reported until 1956, when Galaxy Minerals Ltd. acquired 46 located claims and six Crown-granted claims, including the Evening Star and Golden Star. Trenching and 441 metres of diamond drilling was carried out between 1956 and 1957.
Exploration work resumed in 1961, and geophysical surveys, trenching and extensive diamond drilling totalling 5225 metres over 38 drillholes were carried out between 1961 and 1964. The company name was changed in 1964 to Galaxy Copper Ltd.
In 1965, Vanco Explorations Limited optioned the Galaxy ground and a number of adjacent properties. Geophysical, geochemical and geological surveys were carried out by Sulmac Exploration Services Limited on Galaxy ground, including diamond drilling totalling 2418 metres over 24 drillholes. The option was dropped in May 1966.
Galaxy Copper Ltd. amalgamated with Bata Resources Ltd. and Stampede Oils Ltd. to form United Bata Resources Limited in October 1968. By an agreement dated January 1, 1969, United Bata optioned a 50 per cent interest in the property to Kimberley Copper Mines Ltd. Work by Kimberley during the latter part of 1969 included rehabilitation of the old Evening Star shaft and drifting to the south, east and north at 24.3 metres below the shaft collar; a total of 188.9 metres of drifting was reported. Surface diamond drilling was done in 16 holes totalling 1524 metres. This non-NI 43-101 work identified "3,628,400 tonnes proven and 1,814,200 tonnes indicated of mineralization which has an average assay value of 0.58 per cent copper" (United Bata Resources Limited Report, May 15, 1969).
In 1970, metallurgical testing was carried out by Bethlehem Copper on two bulk samples from the underground workings, though no results are available.
United Bata was acquired as a subsidiary of Pan Ocean Oil Corporation. The option agreement with Kimberley Copper was transferred to a new subsidiary, United Bata Resources (Canada) Ltd., which was incorporated in December 1970. The latter company name was changed in July 1971 to Pan Ocean Oil Ltd. Kimberley Copper Mines underwent a name change in February 1971 to Nor West Kim Resources Ltd.
Work under the option agreement resumed in 1971. The northwest drift was extended at the 24.4-metre level to a point 365 metres northwest of the shaft, where a raise was put up 31 metres to the surface. A total of 401.1 metres of drifting, 1333.2 metres of surface and 327.3 metres of underground diamond drilling was performed on the Evening Star claim. The option was subsequently abandoned.
In 1973, Teck Corporation conducted induced polarization and resistivity surveys on the Makaoo property, including the current Galaxy property. The induced polarization survey identified a possible northwest-trending chargeability anomaly on the Sugar 2 through 4 claims, east of the Galaxy zone, although this target has not been tested (Assessment Report 29628, 4317).
Pan Ocean optioned the property to Canadian Superior Exploration Limited, who carried out a 3444.25-metre magnetometer survey in 1977 and attributed the results to the relative abundance of magnetite in the underlying rock. The survey identified two magnetic anomalies, and eight percussion drill holes totalling 731 metres were drilled to test the targets; results were generally negative (Assessment Report 6864). Additionally, the company completed topographic and orthophotographic plans of the property.
Aberford Resources Ltd was incorporated in April 1982 to acquire the mineral assets of Pan Ocean Oil and of other companies. In October 1985, Aberford incorporated Abermin Corporation to continue their mineral exploration activities. Abermin owned 100 per cent interest in the Galaxy property, which had an indicated non-NI 43 101 resource of 2 267 750 tonnes at 0.6 per cent copper and 0.51 gram per tonne gold (Abermin Corporation, Information Booklet, December 30, 1985, page 53).
In 1987, Abermin completed seven percussion drill holes on the Evening Star Crown grant and Rocket 11 mineral claim totalling 367 metres. Drill results near Galaxy Lake were considered disappointing in light of previous results (Assessment Report 16334).
In 1990, Getchell Resources Inc. acquired the property from Abermin and completed eight percussion drill holes totalling 649 metres. Results show a combined weighted average of 0.74 per cent copper over an average intercept of 40.23 metres (Assessment Report 20242).
Between 1990 and 1996, non-NI 43-101 resource estimates for the Galaxy deposit were 3.2 million tonnes grading 0.65 per cent copper and 0.34 gram per tonne gold (Assessment Report 20242). Reserve estimates are based on earlier drilling programs and underground exploration work and are hampered by a lack of complete assay data and by very poor core recoveries.
In 1996, under an Afton Mining Ltd. option agreement with Getchell Resources Inc., Teck Corporation completed a 32-hole diamond drilling program on the property. Despite the previously estimated non-NI 43-101 resource, upon reviewing recent results of their drill program Teck decided not to continue with further exploration or development; subsequently, Afton Mining dropped their option on the property (Information Circular 1997-1; Assessment Report 29628).
In 2000, Getchell Resource Corp. was renamed Discovery-Corp Enterprises Inc. The company entered into an option agreement with Snowfield Development Corp, although no work was completed on the property. The agreement ended August 1, 2002.
In 2006, Discovery-Corp drilled three diamond drill holes totalling 286.2 metres, with the best results from selected samples reporting 0.72 per cent copper and 0.46 gram per tonne gold across a 12.47-metre interval in drillhole GX06-1 (Assessment Report 28674). The company also conducted geological mapping and rock sampling.
In 2007, Discovery-Corp completed property-scale work including gridding, surveying, 612 soil samples and a 15.75-line-kilometre ground magnetometer survey. Soil sampling identified a 300 by 150-metre zone of copper and gold anomalies over the Galaxy zone. A magnetic high, identified by the geophysics survey, coincided with these results (Assessment Report 29628).
In 2012, Discovery-Corp completed three diamond drill holes totalling 305 metres. Results include Drillhole GX12-05, which assayed 0.61 per cent copper, 0.11 gram per tonne gold, 1 gram per tonne silver and 0.11 gram per tonne palladium (Press Release, Discovery-Corp Enterprises Inc., November 26, 2012).