The Takla-Rainbow developed prospect is situated in the Swannell Ranges (Omineca Mountains) near the headwaters of Twin Creek, approximately 52 kilometres west of Manson Creek. The area first became of interest in 1970, when the N.B.C. Syndicate staked an east trending zone of chalcopyrite-pyrite mineralization hosted by an embayment of volcanic rocks along the east contact of the Late Triassic-Early Cretaceous Hogem Intrusive Complex.
The northwest trending tongue of volcanic rocks belongs to the Lower Jurassic Twin Creek Formation of the Middle Triassic-Lower Jurassic Takla Group. It is intruded by Early Jurassic granodiorite and quartz monzonite phases and an Early Cretaceous granite phase of the Hogem Intrusive Complex. The original nature of these rocks is commonly obscured by intense hydrothermal alteration. Most of the strongly altered volcanic rocks in the area are geochemically anomalous in gold and silver.
The principal rock type exposed in the area is massive to porphyritic, fine-grained andesite assigned to the Takla Group. Minor amounts of chloritized basalt flows, coarse volcanic breccia, and lapilli tuffs are also present. The andesite has been moderately to intensely chloritized and comprises blocky grains of plagioclase cemented by a network matrix of intergranular, fine-grained chlorite. The plagioclase grains are strongly altered to fine-grained sericite with lesser chlorite and carbonate. The rock is cut by veinlets of carbonate (dolomite/ankerite/calcite) and epidote is concentrated in rather diffuse, vein-like zones of microbrecciation. Minor pockets of potassium feldspar appear spatially related to some of the altered fracture zones. The volcanics are upward-facing and dip gently (approximately 15 degrees) to the southwest.
The dominant structural features affecting these rocks are northwest-striking faults. The regional-scale Twin Creek fault passes through the Takla-Rainbow property (Open File 1993-4). Stratigraphic offsets suggest a southwest-side-down normal motion on the fault. Drilling has indicated that at least three, subvertically dipping fault structures exist and that zones of related brecciation in the volcanics and intrusions reach 23 metres wide. Closely spaced subparallel systems of sheeted microfractures in the porphyritic volcanics also seem to be the locus of carbonate and epidote alteration. A second, northeast striking fault system is also present in the area.
Mineralization occurs in three closely spaced zones: the West, East and South zones. Within these zones, mineralization occurs in one or more parallel, steeply dipping, northwest-striking shears within or adjacent to intrusive rocks. The majority of the testing to date has been carried out in the West zone, which underlies the upper reaches of Twin Creek.
At the West zone, mineralization is spatially and probably genetically related to the emplacement of a northwest striking intrusive body confined to the contact between Takla Group volcanics to the south and a dioritic boarder phase of the Hogem Intrusive Complex to the north. The presence of abundant orthoclase megacrystic granite dikes, many of them sheared, within the Twin Creek fault suggests syn-plutonic, probably Cretaceous-aged motion and mineralization (Fieldwork 1992, page 87).
The zone, which consists of up to five parallel, subvertical gold-bearing structures, measures 289 metres along strike by 100 metres wide and extends to a depth of 140 metres. It occurs within a strong pyritic halo measuring over 1000 metres in length and 150 metres in width. The most common type of mineralization intersected in drillholes is in the form of narrow quartz fillings along fractures ranging up to several decimetres in width, and as disseminations of sulphides and native gold in both porphyries and volcanics. Mineral association in the zone is represented by pyrite, chalcopyrite, quartz, native gold, carbonates, sericite, chlorite and minor pyrrhotite, magnetite, galena, sphalerite, and specular hematite. This mineralization is confined to zones marked by microshearing, intense fracturing, pyritization, carbonatization and silicification. Gold is in its native form and gold-pyrite and gold-chalcopyrite associations are common.
The East zone measures 183 metres along strike, is 130 metres wide and extends 140 metres below surface. The zone contains two or more parallel subvertical gold-bearing structures. To the west, the zone is bound by weak mineralization and the eastern boundary is undefined.
The South zone is largely untested and measures approximately 275 metres along strike. The zone is bound by weak mineralization on the west side and seems to be cut off to the east. A 2.99 metre wide mineralized drill intersection grading 5.83 grams per tonne was made at a depth of 180 metres in 1987 (Assessment Report 17013, page 26).
The ridge south of the Twin Creek fault is underlain by a strong quartz-kaolinite-pyrite alteration zone, capped by a discontinuous, horizontal alunite-quartz zone up to 5 metres thick that extends over 500 metres. It represents an unexplored epithermal target (Fieldwork 1992, page 105).
In 1969 and 1970, the NBC syndicate carried out a silt sampling, soil sampling, and regional mapping program on the Twin claims. Their work outlined an 1800- to 2100-metre long copper soil anomaly.
In 1971, the property was optioned by Falconbridge Mines, whose program included geological mapping, a magnetometer survey and 10 diamond drill holes, totalling 141 metres, of EX core. Significant drilling results included: NBC #1, which yielded 15.2 metres of 0.35 per cent copper; NBC #2, which yielded 18.9 metres of 0.24 per cent copper; NBC #7, which yielded 15.5 metres of 0.30 per cent copper and NBC #8, which yielded 14.9 metres of 0.24 per cent copper (Assessment Report 20511).
Also in 1971 and 1972, Noranda Exploration conducted a program on their Loop property, which overlaps with the northeast corner of the present day Takla-Rainbow property. Their work consisted of a soil geochemical survey and induced polarization survey, which outlined several zones with geochemical copper anomalies of greater than 140 parts per million copper (Assessment Report 3269). Further limited work was carried out in 1972 by Wesfrob Mines and in 1973 by Hudson Bay Mining and Exploration.
In 1981, L.B. Warren and N.A. Scafe staked the Twin 1-6 claims for their gold potential. They collected two samples from an old trench which assayed 19.54 and 23.31 grams per tonne gold, respectively. Also at this time, two rock samples (ERT-9 and -10) from the North Ridge area, located approximately 1 kilometre north of the main Takla-Rainbow zone, yielded values of 0.14 and 0.15 gram per tonne gold with 0.215 and 0.135 per cent copper, respectively (Assessment Report 12162).
The property was examined by Mattagami Lake Exploration, S.E.R.E.M. and Newmont, none of which were able to reproduce the results from the trench. In 1983, Amir Mines optioned the property and contracted Bema Industries Ltd to prospect and sample.
In 1983, a regional exploration program initiated by Imperial Metals, along the Pinchi fault zone, located the presence of anomalous gold values on Twin Creek. On the basis of their results the Takla and Rainbow claims were staked. In 1984, a grid was established. Geochemical soil sampling revealed the presence of a widespread soil gold and zinc anomaly 400 by 1000 metres, with elevated copper values on the northern part of the grid. In 1984, a sample (6253) from the west zone yielded 31.6 grams per tonne gold (Assessment Report 14103).
In 1985, the Twin 1-6 claims were optioned by Imperial Metals. Work that year consisted of extending the grid to the west, detailed geological mapping, geochemical soil sampling, an induced polarization survey and diamond drilling. Soil sampling, on the West Grid, outlined the presence of a large zone anomalous in gold (up to 990 parts per billion gold) 1000 metres long and from 50 to 150 metres wide. In addition, several smaller anomalous gold zones were also outlined. The induced polarization survey was conducted over both the older East Grid and the newer West Grid. On the West Grid, a zone of anomalous chargeability was delineated for over 900 metres. This anomaly was assumed to be related to the volcanic-intrusive contact present. Four holes totalling 312 metres of BQ diamond drilling was completed. Drilling intersected mineralization in the form of sulphide-bearing quartz stringers and disseminations, over a strike length of 550 metres. Intersections ranged in width from 0.30 to 1.98 metres with values of 58.6 to 623.0 grams per tonne gold, 82.3 to 1187 grams per tonne silver and 0.03 to 6.92 per cent copper being recorded (Assessment Report 14103).
Work by Imperial Metals in 1986 included the establishment of three new grids; the TRN, TRS and TRS #2. Geological mapping and geochemical soil sampling were conducted on these grids. Gold, silver, and copper anomalies on the TRN grid were outlined across the southern and eastern parts of the grid. On the TRS and TRS #2 grids, several large gold anomalies up to 450 by 150 metres and 500 by 75 metres as well as numerous smaller gold anomalies were present. Numerous silver anomalies were present, the largest measuring 500 by 150 metres. Numerous copper anomalies were also present but primarily on the western part of the TRS grid. A diamond drilling program of fourteen holes totalling 1748 metres of BQ core was completed over the main zone on the East and West grids. Drilling tested the zone for over 700 metres of strike length and showed it to be open at depth and to the east along strike. The best result was a 1.5-metre intersection in DDH #13 containing 23.66 grams per tonne gold (Assessment Report 15487).
Prior to 1987, the Takla-Rainbow property is listed as being owned and operated by Imperial Metals Corporation. In 1987, the operator was still Imperial Gold but Cathedral Gold Corporation is listed as owner.
In 1987, Imperial Metals exploration program included geochemical soil sampling, geophysical induced polarization and VLF surveys, geological mapping, prospecting, and diamond drilling. Soil sampling of the TRS Grid indicated the continuation of gold anomalies to the south and west of previous sampling with the exception of the southwest corner. The highest anomaly recorded was 2.36 grams per tonne gold located near a 25 metre wide shear/fault zone. In addition, four kilometres of soil traversing were completed with 98 samples being collected, indicating the presence of anomalous gold in several areas. The results of the VLF survey indicated the presence of several weak to moderate VLF conductors with strikes varying from the regional trend of northwest to north. The results of the induced polarization survey outlined the presence of several weak northwest to southeast trending chargeability anomalies. A total of 23 holes totalling 6042 metres of BQ diamond drill core were completed. Nineteen holes totalling 5407 metres were drilled on the TR West Grid in order to better define the mineralization discovered by previous drilling. The best intersection from the Takla-Rainbow zone was 2.5 metres wide with a grade of 39.43 grams per tonne gold and 411.43 grams per tonne silver and 1.28 metres of 37.00 grams per tonne gold, both from the West zone; 1.30 metres of 7.85 grams per tonne gold from the East zone; and 2.99 metres of 5.76 grams per tonne gold from the South zone (Assessment Report 16759; Property File Rimfire - Cathedral Gold Corp., 1988).
Also at this time, in 1987, a float sample (TG-16-R) from the North Ridge zone assayed 0.395 gram per tonne gold, whereas a talus sample (TG-196-R) of carbonate-altered volcanics with quartz veining and malachite staining, located approximately half way between the North Ridge and West zones, yielded 0.124 per cent copper and 0.198 gram per tonne gold (Assessment Report 16759). Grab samples of malachite- and azurite-stained volcanic siltstone from a north-facing slope of a northwest-trending ridge, located approximately 750 metres west of the West zone, yielded up to 0.882 per cent copper, 5.8 grams per tonne silver and 0.175 gram per tonne gold (Sample TG-57-R; Assessment Report 16759).
Total undiluted, uncut, drill indicated (inferred) historic resource of 199 580 tonnes grading 13.71 grams per tonne gold have been outlined at the West and East zones (Assessment Report 17013, page 27). This figure was calculated using a 3.43 grams per tonne cut-off grade and a minimum mining width of 1.22 metres.
In 1988, Imperial Metals conducted a program of diamond drilling and trenching on the West drill grid. A total of 132 metres of trenches were excavated with the best grab sample grading 391.89 grams per tonne. Thirty-eight holes totalling 7472 metres of BQ core were drilled. The best assay obtained was in DDH-40 from a 1.52 metre intersection of 28.66 grams per tonne gold. An estimate from drilling done on the property indicated inferred and potential resources at 291,239 tonnes at 8.57 grams per tonne gold (Assessment Report 20511).
In 1990, Eastfield Resources Ltd. carried out 424 kilometres of ground electromagnetic (VLF) and ground magnetic surveying. The magnetic data was reported to have probably outlined several linear zones of high response that generally correspond to the intrusive complex-volcanic contact area.
In 1991, exploration conducted by Mincord Exploration Consultants Ltd. on behalf of Eastfield Resources Ltd. included soil sampling (1274 samples), road building, trenching (679 metres in 12 trenches), chip sampling, prospecting, induced polarization surveys (36.2 kilometres), geological mapping, an airborne magnetic and VLF/EM survey (624 kilometres) and the drilling of eight NQ diamond-drill holes totalling 1241.6 metres.
Also in 1990 and 1991, Golden Rule Resources Ltd. completed programs of geological mapping, geochemical (rock, silt, and soil) sampling and a 1500 line-kilometre airborne geophysical survey on the area as the Takla property.
In 1990, a grab sample (TR-90-D54) from a quartz-veined tuff hosting massive pyrite and disseminated chalcopyrite associated with a narrow shear zone, located up slope to the north of the West zone at an elevation of approximately 1675 metres, assayed 1.17 per cent copper, 0.011 per cent molybdenum, 14.4 grams per tonne silver and 1.59 grams per tonne gold, whereas another grab sample (TR-90-I34) of diorite with malachite and azurite staining associated with a hematite-limonite–stained and epidote-altered shear zone, taken further upslope to the north of the previous sample, yielded 0.33 per cent copper, 21.3 grams per tonne silver and 1.67 grams per tonne gold (Assessment Report 22372).
Also at this time, two grab samples (RT-90-D11 and -D12) of sheared tuff with disseminated chalcopyrite and malachite staining, located on a north east and north-facing slope approximately 300 metres west and 500 metres west-southwest of the West zone yielded 1.48 and 2.81 per cent copper, 12.9 and 17.0 grams per tonne silver with 0.74 and 0.98 gram per tonne gold, respectively (Assessment Report 22372).
In 1991, three grab samples (TR-91-R2, -R4 and -R13) of silica-epidote–altered diorite with disseminated to blebby chalcopyrite, pyrite, magnetite and malachite, located up slope to the north of the West zone at an elevations of approximately 1650 to 1690 metres, yielded values from 0.23 to 0.49 per cent copper, 1.6 to 4.8 grams per tonne silver and 0.11 to 1.28 grams per tonne gold (Assessment Report 22372).
During 2005 through 2010, Redton Resources and Geoinformatics Exploration Canada Inc. undertook work on the regionally extensive Redton property, which covered the Falcon (MINFILE 093N 068) occurrence to the south (just north of Nation Lake) and north to the Tak (MINFILE 093N 067) occurrence, approximately 6 kilometres south of the Omineca River.
In 2005, a 5764.0 line-kilometre airborne magnetic and electromagnetic survey was completed on the area as the Takla-Redton property. In 2006, a program of geological mapping and geochemical (rock, silt, and soil) sampling was completed on the property along with 12 diamond drill holes, totalling 4032.5 metres, on the Takla-Rainbow (MINFILE 093N 082) and Tak occurrences.
In 2006, diamond drilling on the Rainbow zone yielded up to 0.16 and 0.17 per cent copper, 0.003 and 0.002 per cent molybdenum, 0.11 and 0.22 gram per tonne gold with 1.3 and 0.9 gram per tonne silver over 96.7 and 112.0 metres (3.3 to 100.0 and 238.0 to 350.0 metres down hole) in hole RB06-01 (Assessment Report 29011). The hole intersected potassic-propylitic–altered microdiorite with several zones of copper mineralization that could be related to the Red porphyry-copper occurrence to the west-northwest or to a separate mineralized porphyry cupola, as yet undetected by drilling.
In 2007 and 2008, programs of geochemical sampling (rock, silt, and soil) sampling, ground geophysical surveys and 10 diamond drill holes, totalling 3784.0 metres, were completed on the property. This work centred primarily on the Takla-Rainbow occurrence to the north and Falcon occurrence to the south. In 2010, a subsequent AeroTEM survey by Redton Resources identified 65 electromagnetic anomalies on the property.
In 2011, Kiska Metals Corp. (previously Rimfire Minerals Corporation) completed a program of prospecting, geological mapping, geochemical (rock, silt, and soil) sampling and a 64.0 line-kilometre induced polarization survey on the Redton property. The induced polarization survey was undertaken on a till-covered area near the Falcon occurrence.
By 2013, the Takla-Rainbow was no longer part of the larger Redton property that extended south to Nation Lakes. Manado Gold Corp. optioned the Takla Rainbow from CJL Enterprises Ltd. The 2013 exploration program for Manado Gold Corp. consisted of a helicopter-supported diamond drilling program that included five NQ2-size drillholes totalling 605.8 metres (Assessment Report 34850). The results for drillholes TR13-84 and TR13-85 failed to confirm the gold mineralization reportedly intersected by two historic drillholes (DDH-013 and 039). It is suspected that local faulting between the historic and recent drillholes may have displaced the earlier reported mineralization. Drillhole TR13-86 tested for the northwestern extension of the West zone and intersected several 8 to 10 metre intervals with interesting but lower grade gold and silver-bearing sulphide mineralization. Drillholes TR13-87 and TR13-88 tested the central and southeastern extension of the West zone, respectively. Both drillholes intersected several mineralized zones with strong to intense quartz flooding and pyrite mineralization with associated trace to significant precious and base metal mineralization. Drillhole TR13-88 yielded a 24.52 metre intersection (66.0 to 90.52 metres) near its terminus with a weighted average grade of 2.011 grams per tonne gold and 2.0 grams per tonne silver, including a 6.0-metre intersection (68.0 to 74.0 metres) grading 4.225 grams per tonne gold, 4.0 grams per tonne silver and 0.36 per cent copper (Assessment Report 34850).