Voigtberg, B.C. Geological Overview
2014/04/22 BCGold Corp. Consolidates Interest In Voigtberg Copper–Gold Property Read Release
2011/01/31 BCGold Corp. Provides Exploration Update Read Release
2010/09/21 BCGold Corp. Amends Voigtberg Property Agreement with Kaminak Gold Corp. Read Release
2010/09/08 BCGold Corp. Commences Exploration Program at Voigtberg Property, B.C. Read Release
2009/09/14 BCGold Corp. – Kaminak Gold Corp Amend Voigtberg Agreement Read Release
The Voigtberg property is a 2,900 hectare porphyry copper-gold-molybdenum project located 130 kilometres northwest of Stewart, British Columbia.
The Voigtberg Property covers an area of Triassic accreted marine sedimentary and volcanic rocks of the Stuhini Group, which have been intruded by at least 2 generations of feldspar porphyry dykes and stocks of unknown ages.
Only very limited detailed geological mapping has taken place so far on the Voigtberg Property. The mapping is mainly confined to the area where the soil sampling grid was established in the 1990s. Most of the northern and central parts of the claims are covered by glaciers and access to outcrops is very difficult due to extreme topography and glacial cover. Outcrops mapped in the northern claims are dominated by mafic volcanic and intrusive rocks in the west and fine grained clastic sedimentary rocks and intrusive rocks (mainly diorite) in the east. Interpretation of relationships between the units in the northern portions of the Property is limited by accessibility and exposure.
The southeastern parts of the claims are dominated by relatively unaltered and unmineralised clastic sedimentary rocks, limestone and lesser mafic volcanic rocks, which have been intruded by dykes.
The southern part of the Voigtberg claim block comprises Stuhini Group mafic volcanic rocks and marine sedimentary rocks and limestone. These rocks trend north to north-easterly and dip moderately to shallowly to the north-west and south-east. The central portion is dominated by at least two generations of porphyritic intrusions and as many as 4 potentially related porphyritic intrusions. Mapping in 2006 and 2007 identified mineralization that is similar to features at Galore Creek. This mapping resulted in the reinterpretation of certain intrusions to potentially being part of the same geological suite as the Galore Creek Copper-Gold-Silver (Cu-Au-Ag) deposit, owned by NovaGold Inc. and Teck-Cominco Ltd. Namely; this is the Late Triassic Copper Mountain Suite.
The Gold Zone covers a northeast elongated 400 x 650 metre area that is coincident with a > 300 parts per billion (ppb) Au in soil anomaly and a chargeability high. The Gold Zone is bounded to the west by glacial cover, to the southeast by a zone of argillically altered intrusive rock (Gossan Zone) and to the southwest by an area of fresh limestone cover. The Gold Zone comprises sericite, carbonate, chlorite altered andesite and dacite lapilli tuff, with disseminated and fracture coated pyrite. Extensive cover limits mapping and interpretation of mineralization and alteration in this zone. Gold and molybdenum (Mo) are elevated in this area and pyrite mineralization is associated with low temperature sericite, carbonate, chlorite alteration assemblages, indicating that the style of mineralization present at the Gold Zone is distal from the source of the hydrothermal fluids. Mineralization here is thought to represent a gold-rich halo located on the periphery of a porphyry copper-molybdenum system, which could potentially lie to the south of these zones.
The North Zone covers a north-south elongated 900 x 600 metre area that is coincident with a > 100 ppb Au, > 100 parts per million (ppm) Mo and > 250 ppm Cu in soil anomaly and a chargeability high. The area is bounded to the north, east and west by glacial cover and to the south by a zone of propyllitically altered andesitic volcanic rocks. The North Zone has extensive cover and extreme topography making exploration difficult. From the limited amount of work done in the North Zone, it appears similar in terms of alteration and mineralization style to the Gold Zone, aside from northwest trending shear-hosted Cu-sulphides. However, the area has distinct soil geochemistry. Similar to the Gold Zone, gold in soil is consistently > 100 ppb through the whole zone but is coincident with increases in copper, molybdenum and to some extent silver. The North Zone is believed to represent the copper-molybdenum porphyry intrusive “core” of the Voigtberg mineralizing system.
The Moly Zone covers an area of 200 x 100 metres. Within this zone is an area of molybdenite mineralization covering a surface area of 60 x 20 metres which is covered by glacial ice to the northeast, where the mineralization remains open. Mineralization consists mainly of fracture coated and disseminated very fine-grained molybdenite with lesser sphalerite, chalcopyrite and galena. The sulphide minerals are concentrated along fractures and also along flow foliation surfaces within dacitic units. Mapping and prospecting to the east produced two samples with significant molybdenum mineralization and similar geology, and may represent an extension of the zone.
The Gossan Zone covers an elongated 800 x 600 metre area within which a prominent limonitic gossan extends for at least 300 metres. The area immediately north of the Gossan Zone is dominated by fresh limestone, which masks the underlying alteration and mineralization. Mapping in the western portion of the anomaly is severely limited by glacial till cover and alpine grasses and shrubs. Within the gossanous area several narrow pinching and swelling massive sulphide veins are present. These veins consist mainly of pyrite with lesser sphalerite and rare galena and chalcopyrite. Given the veins’ orientation, spatial relationship to other known mineralization styles, associated alteration assemblages, and polymetallic geochemistry, these veins may represent polymetallic veins which developed near porphyry Cu-Mo style mineralization.