Copper Gold Porphyry
Lake Lemare Property, Western British Columbia
The Le Mare property comprises 17 map-staked claims covering 6,198.061 hectares (15,309.21 acres) in the Nanaimo Mining Division and in the Rupert Land District of western British Columbia. It is located on N.T.S. map sheet 92 L/5, as well as on B.C. map sheets: 092L 031 and 041.
The Le Mare hydrothermal system is located on crown land in the southwestern part of the property-area. The Mah-te-nicht No. 8 Indian Reserve is located adjacent with the northeastern property boundary, about 4.5 km (2.75 mi) north-northeast of, and in a different drainage from the Le Mare hydrothermal system. However, if ocean-going barge loading facilities were to be developed on the south shore of Quatsino Sound, the Quatsino Band would become involved in the design and construction of those facilities. J.T. Shearer has been consulting with the Quatsino Band Council since February, 2008 with regard to exploration of the Le Mare property. There is no plant or equipment, inventory, mine or mill structure of any value on these claims. Currently, an environmental bond of $4,000 is posted under Permit No. MX-8-253 for road renovation and the development of potential drill sites.
The Le Mare property is located near the northwestern end of Vancouver Island. It is bounded in part to the west by the Pacific Ocean and to the north by Quatsino Sound. A massif in the northwestern part of the property culminates in the peak of Mount Bury at an elevation of about 610 m (2,000 ft). Another massif that hosts the Le Mare hydrothermal system occupies the property’s southwestern part. Le Mare Peak is a 762-m (2,500-ft) high promontory located near the massif’s centre. These steep-sided massifs are separated by the relatively flat Mahatta and Culleet creek valleys. The surface of Le Mare Lake, located in the Culleet Creek valley near the property centre, is at an elevation of about 25 m (82 ft).
About 70% of the original west-coast rain forest in the property-area has been clear-cut during the past 20 years. Most of the slopes underlain by the Le Mare hydrothermal system are either bare, or covered with dense juvenile secondary forest growth. Little timber suitable for mining is left on the property.
The northern end of Vancouver Island is accessible by boat, barge, and by road via the Island Highway (B.C. Highway 19) which transects the town of Port McNeill on the island’s northeastern coast. B.C. Highway 25, a secondary paved road, connects Port McNeill with Port Alice located near the head of Neroutsos Inlet. Access from Port Alice to the Le Mare property area is via a series of well-maintained logging roads passable by 2-wheel drive vehicles during drier times during the year. Most of the property-area is covered by a system of logging roads in various states of repair. Barge loading facilities to support an open-pit mine could be developed on the sheltered southern shore of Quatsino Sound near the property’s northern boundary.
Port McNeill is the nearest town with sufficient supply and service capacity to support an exploration or drilling program. The industrialized areas of southwestern British Columbia are readily accessible via water, road, and air from Port McNeill. Accommodations and basic supplies for an exploration field crew are available at Port Alice and Winter Harbour, located northwest of Quatsino Sound.
The Quatsino Sound area experiences cool wet winters and cool, moderately wet summers. Snow falls in the property-area by December and stays on the ground very briefly at higher elevations.
The current exploration target, the Le Mare hydrothermal system, is on crown land with no special restrictions on development thereon.
The Le Mare property is remote from any power transmission line. However, ocean-going barge transport to the property area would reduce the cost of fuel for diesel power generation. Creeks south and east of the property area could be dammed in order to generate power for a mine-mill complex. Water for milling could be drawn from Culleet or Gooding creeks, or from the outflow from a nearby generating station. An acceptable mill site and tailings storage areas could be constructed in the floors of the Gooding Creek and upper Culleet Creek valleys.
The Port McNeill-Port Hardy area has already demonstrated that it was able to attract personnel to work at the Island Copper mine located between the two towns. That area has sufficient amenities to attract the people needed to operate a new mine near to it.
The Le Mare property hosts mostly mafic volcanic rocks of the Early to Middle Jurassic-age Bonanza Supergroup, including auto-breccias, lahars, and minor amounts of tuff and other pyroclastic beds. Rhyolitic rocks comprise a minor amount of the stratigraphy in the property-area. These volcanic rocks are intruded by felsic dykes that may be equivalent to the rhyodacitic porphyries that are associated with mineralization at the Island Copper Cluster deposits located about 32 km (19.3mi) east-northeast of the Le Mare hydrothermal system. The volcanic rocks at the Le Mare hydrothermal system have deformed into a series of open to close outcrop-scale drape-folds related to local intrusion. Regional and contact metamorphism do not exceed lower the greenschist facies.
The Le Mare hydrothermal system has been just barely unroofed by erosion. The top of the potassic alteration zone is exposed along the crests of Le Mare and Gooding ridges, located between Le Mare Lake and Gooding Cove in the southwestern part of the property. Local magnetic field gradient indicates that this system occupies a 5 X 3 km (3.05 X 1.83 mi) or 15km2 (5.6 mi2) oval-shaped area, that may be hosted by a dilational jog in a regional right-lateral fault system. The proposed fault system is similar to the one that hosts the Island Copper Cluster deposits near Port McNeill, British Columbia.
At surface, copper mineralization occurs in discrete showings-areas, located preferentially in the central parts of sub-vertical hydrothermal plumes. These plumes have core-zones of orthoclase-quartz-biotite (potassic) alteration, enveloped in siliceous exteriors. The gradual decrease in the orthoclase:quartz ratio from about 4:1 in potassic core zones to less than 1:20 in siliceous envelopes, indicates that peripheral silicification is a distal phase of the core-zone potassic alteration and is not overprinted by it. Orthoclase-quartz-biotite alteration is succeeded by quartz-jasper alteration; both phases are mineralized with chalcopyrite, and minor amounts of bornite. This potassic alteration is accompanied by co-incident soil-copper and magnetic anomalies. Discovering economically viable concentrations of copper mineralization within the Le Mare hydrothermal system depends on the successful identification of zones where these hydrothermal plumes and copper occurrences coalesce.
Molybdenum enrichment occurs in areas flanking phyllic alteration in a 600-m (1,968.5-ft) diameter alteration plume, covering a 0.28 km2 (0.1 mi2) area in the eastern part of system in the South Gossan zone. Another, much less extensive plume of argillic-phyllic alteration, is exposed between the Culleet Creek zone and Culleet Lake in the system’s northwestern part. These two plumes cover less than 2% of the total exposure- area of the Le Mare hydrothermal system. Argillic-phyllic alteration post-dates and overprints potassic alteration.
Both sample results and the distribution of soil-copper and molybdenum anomalies, demonstrate that copper and molybdenum mineralization are associated with early potassic and subsequent argillic-phyllic alteration events respectively. They occur together in significant amounts only where molybdenum enrichment has overprinted that of copper.
Most aspects of the Le Mare hydrothermal system are similar with those of the Island Copper Cluster deposits. Geology, alteration, and mineralization at surface at the Le Mare hydrothermal system correspond with those attributes at the Island Copper mine above the main deposit. These similarities indicate that the Le Mare hydrothermal system may host a calc-alkalic porphyry copper-molybdenum deposit of the Island Copper Cluster type.
The Early Jurassic-age land surface above the Le Mare hydrothermal system and whatever near- surface hot-spring environment that it may have hosted, has been lost to erosion. Only a few narrow roots of late, advanced argillic alteration occur in the argillic-phyllic alteration plume in the South Gossan zone. They attest to the former existence of hot spring development above the current erosional level.
The Early Jurassic-age land surface above the Le Mare hydrothermal system and whatever near- surface hot-spring environment that it may have hosted, has been lost to erosion. Only a few narrow roots of late, advanced argillic alteration occur in the argillic-phyllic alteration plume in the South Gossan zone. They attest to the former existence of hot spring development above the current erosional level.
Most exploration has been conducted in the north-eastern part of the Le Mare hydrothermal system; its south-eastern part remains sparsely explored to unexplored. Six BQ diamond drill holes penetrated the north-eastern margin of the Le Mare system in 1992. One hole that penetrated the Culleet Creek potassic alteration plume, intersected five 2-m (6.56-ft) and one 4.7-m (15.42-ft) long intersections containing from 500 to 959 ppm copper, which is similar to the tenor of copper mineralization in nearby trenches. Copper mineralization at surface is locally quite variable. The writer’s samples range from 3 ppm to 6.57% copper. Generally, the reproducibility of small-scale sampling is low. Such variability should be expected in mineralization located near the top of the potassic alteration zone of a porphyry copper-molybdenum deposit. Less than 1% of the surface area of the Le Mare hydrothermal system has been drilled.
A two-phase exploration program is recommended. The first phase comprises geological mapping, prospecting, soil survey. If reasonable encouragement is generated by the results of the first-phase program, it should be followed by a second-phase program of 3-dimensional induced polarization and ground-magnetic surveys. The results of the two phases of the recommended work program should produce a three-dimensional assessment of the rock to a depth of about 300 m (984 ft) beneath the surface exposure of the Le Mare hydrothermal system. It is expected that this assessment will be sufficiently detailed to enable precise location of the best target-areas to drill for porphyry copper and molybdenum mineralization.