Virtual Museum ID: 19-BCGS-BRETT-2
Calcite is a soft carbonate mineral that is found as both veins and as the primary mineral in limestone and marble. When in limestone it can host fossils and forms in a deep sea environment. It is also ground up and used in lawncare to raise the pH of acidic soil in the product called lime. When in veins it is often found with quartz.
The information listed below relates to the current holding location or collection that the sample is from, and whether the item is viewable at that location or is part of a private collection. Coordinates are given as guides, and we remind you that collecting specimens from these locations is not allowed. Caution is advised visiting such sites and Below BC assumes no responsibility for any injuries or trespassing charges that may occur as a result of the viewer entering these sites.
Original Collection:British Columbia Geological Survey (BCGS)
Virtual Museum ID:19-BCGS-BRETT-2
Date Added to VM:2019-05-07
Sample Origin:Whiteman Creek Valley, N of Kamloops, B.C.
Specific Site:Brett prospect
Datum:11 (NAD 83)
Primary Mineral Formula:CaCO₃
Advanced Geological Information
The following section provides geological data relating to the specimen or the site it was collected from, when available. Information has been obtained from various sources including private and government datasets but may not be up to date. Any geological time periods or ages listed often relate to the primary geology of the area, and may not be the actual date of an event such as mineral formation.
Geological Formation:Harper Ranch Group
Geological Period:Devonian to Triassic
Stratigraphic Age:419.2 - 201.3 Ma
The Brett epithermal gold-silver prospect is located on the steep north slope of Whiteman Creek Valley, on the western side of Okanagan Lake, immediately north of Kelowna and 29 kilometres west of Vernon. The prospect comprises the Main Shear zone, which hosts the Discovery vein (part of the Bonanza zone), the RW vein and the TR-1 and TR-21 zones.
In this area, Devonian to Triassic sedimentary and volcanic rocks of the Harper Ranch Group are intruded by Middle Jurassic granitic rocks of the informally named Terrace Creek batholith. Eocene Penticton Group or Kamloops Group volcanic rocks overlie the igneous and sedimentary rocks. Eocene Coryell rhyodacite porphyry to syenite plugs and dikes intrude these rocks.
The eastern half of the Brett property is underlain by Jurassic or Cretaceous granitic rocks of the Okanagan Batholith. On the western portion of the property, a 500-metre-thick sequence of nearly flat-lying Tertiary (mostly Eocene) volcanics overlies the Okanagan Batholith rocks. All significant gold showings on the property have been found within the Eocene volcanics. Much of the volcanic sequence consists of amygdaloidal andesite with minor (less than 20 metres thick) basalt flows and tuffaceous horizons ranging from 2 to 40 metres thick. The volcanic stratigraphy can be divided into an upper and lower sequence. The upper sequence consists of thick, massive feldspar porphyritic flows and tuffs believed to be of Miocene age. No significant mineralization has been identified in the upper sequence. The lower sequence consists of a series of water-lain tuffs, flows and coarse andesite to basalt fragmentals. Gold mineralization usually occurs in zones of polymictic tuff that mark the contacts between units, especially coarse fragmental or tuffaceous member contacts. The inter-unit contact zones vary in thickness from 0.2 to 5 metres and occur throughout the stratigraphy.
The Brett deposit has been categorized as a classic epithermal deposit that has been cut by a series of northwest- and northeast-trending shears. Numerous northwest-striking, steeply dipping shear zones that vary in thickness from a few centimetres to several metres occur on the property. The most significant shear zone, the Main Shear zone, occurs over a strike length of over 1300 metres, ranges from 1 to 10 metres in width and has an estimated slip-dip vertical displacement of 40 metres. At least some of the northwest-striking structures formed postmineralization and are not associated with the main mineralizing event.
Precious metal mineralization occurs as mesothermal-type quartz veins in Okanagan Batholith granitic rocks and epithermal-type, structurally controlled shear, vein and silicified zones cutting Tertiary volcanic sequences. Epithermal zones on the property include the Main Shear, New Discovery (MINFILE 082LSW131), East (MINFILE 082LSW084) and Gossan (MINFILE 082LSW132) zones.
A shear zone within the Penticton Group volcanic rocks hosts gold and silver mineralization. The 1500-metre-long shear strikes 155 degrees, dips 80 degrees west for at least 250 metres depth and is 2 to 15 metres wide. Mineralization occurs with quartz and chalcedony in veins, vein stockworks and brecciated veins, in fracture-controlled zones near or within the shear zone and in altered, more porous trachyandesite tuffs and flows adjoining the shear. The veins have crustiform, banded and vuggy textures. Minor mineralization is present in a Coryell feldspar porphyry dike that fills much of the shear zone; however, most mineralization appears to predate the dike. Mineralization is largely structurally controlled but is, in part, lithologically controlled. Pyrite, gold, electrum and minor argentite occur.
Gold mineralization varies from very fine-grained in volcanic rocks to coarse flakes in quartz veining. Most of the gold seems to be concentrated within a 200-metre strike length in the Bonanza zone and the RW vein; furthermore, the best gold values appear to occur between 1230 and 1240-metres elevation. Intense clay alteration is prominent in portions of the shear zone. The tuffs have suffered chlorite-epidote-calcite-hematite alteration changing to clay(illite)-sericite-silica alteration adjacent to the shear zone.
Typical mineralization in the Main Shear zone consists of disseminated gold in silicified and fractured wallrocks. Drilling at the north end of the Main Shear zone encountered several styles of epithermal gold and silver mineralization. The majority of intersections at the north end of the zone are vein- or vein-stockwork–related. Most of the veins are tight with sharp contacts and little wallrock alteration.
The Bonanza zone occurs within the Main Shear zone on the Brett #1 claim. A significant gold-bearing quartz vein, the RW vein, occurs approximately 15 metres west of the Main Shear zone and has a strike of approximately 335 degrees with a 100-metre surface exposure. The vein consists of sheared quartz with a coarse gold content and is believed to be a splay off the Main Shear zone. The RW vein varies in width from less than 0.3 to 1.2 metres and has been shown to pinch out or lose value along strike and downdip. The New Discovery zone is an area yielding anomalous gold results from geochemical sampling. The New Discovery zone occurs east of Brett Creek and is similar to the Main Shear zone. Also, in 2004, a new area called the Bonanza East zone, located approximately 50 metres east of the Main Shear zone, was examined and returned promising core sample assays.
The Stockwork zone is located north the Main Shear zone and approximately 100 metres east of the RW pit. The zone comprises an area of silicification and clay alteration with quartz veining in a fracture zone associated with a major amethyst-bearing porphyry dike. High gold values are reported to be associated with hydrothermal breccia in the immediate wall rock to the dike, which has angular, black basalt fragments within a quartz-carbonate matrix.
In 1939, A. Brewer, a prospector from Vernon, discovered auriferous quartz veins in the Okanagan Batholith on the current Brett #2 claim, approximately 1 kilometre east of what is now termed the high-grade section of the Main Shear zone. Sporadic work, including hand trenching and blasting, was carried out on what is now known as the Brewer showing (MINFILE 082LSW047).
In 1983, Charles Brett encountered significant concentrations of angular gold when panning the subsidiary tributaries of Whiteman Creek. Brett subsequently staked the Brett claim group to cover the Gossan zone (MINFILE 082LSW132) and the previously identified mineralized quartz veins (MINFILE 082LSW047), conducting a preliminary heavy mineral silt sampling program. Later that year, ownership of the group was transferred to Huntington Resources Inc., who hired engineer J.M. Dawson to evaluate the claim area. The Gossan zone was considered to have precious metal hosting potential and was recommended for further work. In 1984, Huntington conducted a detailed geochemical sampling program. Samples collected from the Gossan zone returned sporadic anomalous gold and silver values. Further analysis revealed elevated arsenic and mercury values at the western margin of the Gossan zone. Later that year, a narrow (0.15 metre) epithermal quartz vein was discovered. The vein, called the Discovery vein, is located in the modern Bonanza zone and marked the first discovery of mineralization in what is now known as the Main Shear zone. In 1985, Huntington staked the Brett #3 and #4 claims to cover areas of favourable geology and possible northern extensions of the Main Shear and Gossan zones. That same year, prospecting and geochemical sampling programs identified anomalous gold concentrations in soils and scattered high-grade gold values in quartz float. Road construction in the area uncovered a steeply dipping shear zone approximately 2 metres wide, referred to as the Main Shear zone. A significant quartz vein, the RW vein, was also exposed during road construction.
In 1986, 16 NQ diamond drill holes totalling 795 metres were completed. Drilling focused on the recently discovered Main Shear zone and RW vein and identified 25 intersections with greater than 6 grams per tonne gold or visible gold in the core (Assessment Report 32979). In 1987, a joint venture between Huntington Resources Inc. and Lancana Mining Corporation (later known as Corona Corporation) completed 32 NQ diamond drill holes totalling 2900 metres. Twenty-eight drillholes were drilled along a 580-metre strike length of the Main Shear zone. The majority of significant gold intersections encountered during drilling occurred within a 136-metre strike length of the Main Shear zone. Detailed geochemical sampling east of Brett Creek yielded anomalous gold values in the New Discovery zone (MINFILE 082LSW131), a zone similar to the Main Shear zone. In 1988, 5737.3 metres of diamond drilling and 2834.7 metres of reverse circulation drilling were completed on the property. Several significant intersections were obtained and, in 1989, a two-phase drilling program was completed. Phase I focused on the northern end of the Main Shear zone and consisted of 18 diamond drill holes totalling 2772 metres; Phase II followed up on the results of Phase I and consisted of six diamond drill holes totalling 956.46 metres.
In late 1991, the Beaton/Vicore Mining Contracting Group was offered the mining rights to the property, and Vicore commissioned Egil Livgard, P.Eng., to evaluate its high-grade section. Livgard provided a drill-indicated mineral resource estimate for the property of 12 000 tonnes, averaging 39.4 grams per tonne gold (non-NI 43-101 compliant; Assessment Report 32979); however, the Beaton/Vicore group could not raise financing and the project did not progress.
In 1993, an agreement was signed between Huntington and Liquid Gold Resources Ltd. whereby 24 trenches, including historic Trench-21, were excavated to bedrock and sampled along the Main Shear zone. Assays identified several areas with excellent potential. In November 1993, Liquid Gold followed up the assay results by drilling 19 reverse circulation drill holes into the RW vein and Bonanza zone. During the winter of 1993 to 1994, a new road was established to a portal site and buildings were installed to support underground development, which began in late November 1994 and continued until February 10, 1995. During this period, 360 metres of underground development were completed, including a 240-metre-long adit from the 1205-metre level under the Bonanza zone, and approximately 1400 tonnes of mineralized development muck with an estimated average grade of 4 to 5 grams per tonne gold (Assessment Report 25964) was stockpiled; however, Huntington terminated the agreement with Liquid Gold. Shortly after, Vicore Mining Developments Ltd. placed a lien against the property due to unpaid bills for underground development work completed between 1994 and 1995.
In 1995, Huntington Resources Ltd. concentrated work on mining in the high-grade RW gold vein. Closely spaced sampling of the vein yielded an average grade of 34.35 grams per tonne gold over a strike length of 51.3 metres and across a true width of 0.44 metre (Assessment Report 25964). Previous drilling programs had tested the vein over a vertical range of at least 25 metres. In 1995 and 1996, Huntington Resources Inc. excavated pits over a 115-metre length of the RW Vein and a 55-metre length of the Trench-21 section of the Main Shear zone. Approximately 291 tonnes of ore was produced from the pits. The ore was shipped to the Cominco smelter at Trail for processing. An average grade of 27.74 grams per tonne gold and 63.7 grams per tonne silver was recovered at the smelter (Assessment Report 32979). A 240-metre-long adit on the 1205-metre level was rehabilitated and a 15-metre raise was driven in the Bonanza zone. During the winter of 1995 to 1996, a 54-metre-long bypass was driven around a caved section of the old drift and connected to one of the raises driven in 1995.
The lien placed by Vicore Mine Development Ltd. against the property went to court in mid-1998; in December 1998, Vicore was awarded a 100 per cent interest in the Brett property.
In 1999, Vicore Mine Development Ltd. hired Wayne M. Ash to conduct a general assessment of the property. Two years later, Vicore Mine Development Ltd. carried out a small soil and rock geochemical survey over the Brett #1 claim, identifying several areas of anomalous molybdenum, copper, lead and nickel.
In 2004, the Brett property was acquired by Mosquito Consolidated Gold Mines Ltd. (a subsidiary of Vicore Mine Development Ltd.) and a 50 per cent option was granted to Running Fox Resources Corporation. Work that year included soil surveys, trenching, geological mapping, prospecting, road building, staking 52 additional claim units, resampling old core and drilling 2776 metres of NQ core in 17 drillholes. Significant gold-bearing intersections were encountered in 15 of the 17 drillholes; 4659 soil samples were collected over an approximately 15-square-kilometre area. Extensive gold anomalies were identified over a central portion of the area, including five values in excess of 0.5 gram per tonne gold (Assessment Report 32979). This work resulted in the discovery of several new soil anomalies and mineralized zones and provided valuable information on the distribution, geology and controls of mineralization on the property.
In 2011, Running Fox Resources Corporation became the sole owner of the Brett property. That same year, Running Fox completed 13 NQ2 diamond drill holes totalling 1218 metres on the northern portion of the property. Drilling efforts focused on a structural alteration zone discovered during reconnaissance mapping. Results of the drilling indicated that the targeted zone was most likely not part of the main gold-bearing system.
In 1988, a percussion drill hole intersected a high-grade zone that assayed 100 grams per tonne gold over 44 metres (Property File, Miller, 1989).
In 1993, samples collected from the re-excavated Trench-21 on the Main Shear zone returned assays of 12.7 grams per tonne gold over a true width of 4.41 metres (Assessment Report 25964).
Estimated reserves for the Bonanza zone (along a 150-metre section) are 11 970 tonnes grading 39.12 grams per tonne gold (Stockwatch, July 11, 1996).
Significant results from the 2004 drill program include 10.4 metres in hole 04-02 averaging 10.39 grams per tonne gold and 1.30 metres in hole 04-12 averaging 176.3 grams per tonne gold (Assessment Report 27853). Drillhole 04-12 was the first hole drilled in the Bonanza East zone. In 2011, the most significant results were obtained from two holes drilled to follow up a 2004 surface grab sample that averaged 9.97 grams per tonne gold. Hole 11-11 contained a 0.7-metre intersection averaging 1.14 grams per tonne gold; hole 11-13 contained a 1-metre intersection that returned 1.59 grams per tonne gold (Assessment Report 32979).
In 2014, Ximen Mining Corp. completed a program of soil, rock and biogeochemical sampling, geological mapping, ground magnetic, electromagnetic (VLF) and induced polarization surveys and 13 diamond drill holes, totalling 2977 metres, on the area as the Brett Gold property. Holes B14-01 through B14-05 were drilled to test a new vein target on the 490 Gold Zone. Hole B14-06 was drilled to test the Border Zone, another new discovery on the property. Holes B14-08 through B14-11 were drilled 1 kilometre to the northeast of the Main Zone. Drilling targeted a geophysical anomaly (magnetic low, chargeability high) near the Gossan Zone. Holes B14-07 and 14-12 were drilled 300 to 600 metres north and north west of hole B14-06 and 500 to 900 metres west of the Gossan Zone, to test an IP chargeability anomaly in an area of structural interest.
Drilling on the 490 Gold zone yielded up to 34.18 grams per tonne gold and 6.66 grams per tonne silver over 0.9 metre (0.81 metre true thickness) in hole B14-01, 1.78 grams per tonne gold over 31 metres (30.1 metres true width) in hole B14-04 and 1.91 grams per tonne gold over 16.55 metres (16.1 metres true width) in hole B14-05, while drilling on the Main zone yielded up to 24.7 grams per tonne gold over 1.3 metres (Mroczek, M. (2017-09-22): NI 43-101Technical Report - The Brett Gold Project). Another drill hole (B14-13) was collared approximately 250 metres west off the Main zone to test the Border zone and to intersect the Main and 490 zones approximately 150 metres down dip from hole B14-05. The hole intersected a new mineralized zone is located approximately 50 metres in the hanging wall of the Main zone grading 7.29 grams per tonne gold over 5 metres, including 16.7 grams per tonne gold over 1.5 metres (Mroczek, M. (2017-09-22): NI 43-101Technical Report - The Brett Gold Project).
In 2016, Ximen completed a further 16 diamond drill holes, totalling 2363.86 metres. Drill hole 16-1 tested the northwest trending Main Zone near the northern extent of the existing adit and intercepted an interval with 18.95 grams per tonne gold over 1 metre, including 112 grams per tonne gold and 263 grams per tonne silver over 0.3 metre of quartz-carbonate veining, while two other drill holes (16-11 and 16-17) yielded intercepts including 13.35 and 5.7 grams per tonne gold over 0.58 and 0.5 metre, respectively (Mroczek, M. (2017-09-22): NI 43-101Technical Report - The Brett Gold Project).