Regionally, the area lies adjacent to and includes moderately folded volcanic and sedimentary rocks of the Lower-Middle Jurassic Hazelton Group intruded by a succession of plutons of the Tertiary-Jurassic Coast Plutonic Complex. Hazelton Group rocks include a variety of sandstones, conglomerates and breccias as well as minor intercalated tuffs, siltstones and flow material. Granodiorite is the dominant rock of the Coast Plutonic Complex but stocks and plutons vary from quartz monzonite, quartz diorite to granite. Numerous dike swarms range in composition from granite, quartz monzonite, granodiorite and quartz diorite.
The Georgia River property lies on the eastern contact of the Coast Plutonic Complex intruding Hazelton Group rocks. The area of the mine workings is underlain by an assemblage of epiclastic rocks with intercalated andesitic and basaltic flows. Thin bedded, dark grey siltstones and black argillite with minor limestone and greywacke are also present. The epiclastic rocks consist of angular and unsorted andesitic fragments within a fine-grained sandstone or tuff matrix. The andesitic flows are generally green, massive and plagioclase porphyritic while basaltic flows are dark and massive. These Hazelton Group rocks have been subjected to strong shearing and are generally altered to a chloritic foliated rock in which original textures have been obscured. The Hazelton Group has been intruded by granodiorite dikes and/or sills correlative to the Coast Plutonic Complex and are generally less than 100 metres in width and follow regional trends.
Weak foliation and minor folds are evident in the Hazelton Group rocks. Local schist development is located in areas of faulting in close proximity to intrusive rocks. Foliation approximates bedding and strikes 140 degrees with 50 to 70 degree dips to the southwest. Three distinct fault systems, northwest, north and northeast striking, occur on the property. The first faulting is northwest striking followed by north striking faults, both containing quartz vein material. The northwest striking veins are generally more massive than the north striking veins. Later northeast faulting cuts into and deflects along the north striking faults. A major late northwest striking fault appears to cut off all the structures north of the mine workings. Significant gold, silver, lead, zinc and minor copper mineralization in quartz veins appear to be restricted to the zones of later faulting. Marked gold enrichment appears to be associated with areas of vein intersection.
Quartz veins are found in two distinct systems: wide shear zones striking 320 degrees consisting of quartz vein material and siliceous breccia and, narrower quartz-filled fault fissures with a north strike. Mineralization is concentrated in the quartz-filled north striking fault fissures at points of vein intersections. Seven vein systems have been historically discovered and explored. The northwest striking veins are the Main, Georgia and Gem; the north striking veins are the Southwest, Summit, Bullion and Camp. Recent exploration resulted in four new north striking veins: the Eastmark, East Bob, East and Cobbett; and five northwest striking veins: the CC #1, CC #2, Gem A, Gem Top and Pond. Two other veins, the Zinc and Granodiorite, strike northeast with shallow dips to the southeast.
Three stages of faulting and quartz infusion appear to be related to mineralization at the Georgia River property. The first stage of northwest faulting was followed by later north trending faults. Chlorite schists developed along these fault zones with quartz veins subsequently introduced into the zones. The quartz is sparsely mineralized with pyrite, pyrrhotite, galena and sphalerite with minor arsenopyrite. The second stage is the introduction of granodiorite dikes, formation of fractures, brecciation of early quartz veins and stringers, and deposition of sulphides. The sulphide deposition comprise initial sphalerite-pyrite-rich veins and stringers, low in quartz, and deposited in sericite-altered fracture zones near the granodiorite dikes. This event produces veins generally low in gold and silver values.
Due to the brittle nature of rocks within areas of intersecting veins formed during the first stage, voids formed during brecciation related to the second stage. Marked gold enrichment is observed at these points of intersection. Brecciated quartz with low sulphide content generally carries appreciable gold and silver values in contrast to unbrecciated quartz.
The main quartz phase deposition phase has produced quartz vein material containing seams of massive pyrite, pyrrhotite, sphalerite and galena with minor chalcopyrite and rare arsenopyrite. The quartz rock is brecciated with fracture-filled sulphides. Gold and silver values are related to the sulphides. Pyrite and pyrrhotite form 50 per cent of the sulphides with sphalerite and galena the remaining. Mariposite and/or fuchsite are commonly noted within the chlorite schist wallrock.
The final stage is post-mineralizing fault movement along the vein system and deposition of quartz-calcite veins. This has produced narrow drusy quartz-filled fractures within intrusive rocks. Calcite is commonly found filling fractures in wallrock.
A brief description of the veins is as follows:
1) Main vein - This vein consists of a large silicified shear zone striking 315 degrees and dipping 55 to 65 degrees southwest. It is a siliceous replacement zone composed of layers of siliceous material separated by bands of chlorite schist with silicification gradually fading into the wallrock. This zone has been traced along a strike length of 650 metres and exhibits an offset (6 metres) along the Southwest vein and along the Bullion vein (65 metres). Mineralization is sparse and consists of pyrite, pyrrhotite and minor arsenopyrite. Low gold values (0.1 gram per tonne) have been obtained from this vein (Assessment Report 8547).
2) Georgia vein - This vein strikes parallel to the Main vein about 300 metres north, and is approximately 1 metre in width and is exposed over a strike length of 450 metres. It appears to pinch out to the northwest into a series of quartz veinlets. The vein locally contains siliceous volcanic inclusions with several parallel short and narrow stringers. Mineralization consists of pyrite, pyrrhotite and local concentrations of sphalerite and minor galena. Sampling returned 0.17 gram per tonne gold (Assessment Report 8547). The vein is offset approximately 27 metres along the Southwest vein.
3) Gem, Gem Top and Gem A veins - The Gem vein strikes parallel to the Georgia vein approximately 150 metres to the north and is exposed over a length of 400 metres and is from 1 to 3 metres wide. Mineralization is sparse with local concentrations of pyrite, pyrrhotite, minor sphalerite and rare galena. Two nearby veins, the Gem Top and Gem A, are up to 2 metres wide and sparsely mineralized. Where the Gem vein appears to veer off from a northwest strike to a north strike, pyrite and sphalerite concentrations are higher. Trench samples over 2 metres assayed 8.22 grams per tonne gold (Assessment Report 8547).
4) Southwest vein - This vein has received the bulk of the property exploration work to 1997, being tested by 81 diamond-drill holes. This vein has been exposed by trenching and drilling on surface for 595 metres and a vertical range of 258 metres and has been extensively explored by drifting on two levels (prior to 1937). Past production was from this vein. The vein consists of short, discontinuous and overlapping mineralized quartz lenses along a continuous zone within green chlorite schists. The zone varies from 1 to 4 metres wide and shows evidence of repeated movement along fault zones. Near the intersection of the Georgia, CC #1 and CC #2 veins, the Southwest vein, which consists of 1 to 3 overlapping gold-bearing quartz lenses, contains a zone 80 metres long and 0.94 metre wide averaging 33.25 grams per tonne gold and 38.39 grams per tonne silver (Assessment Report 8547). The individual lenses appear to vary in length from 8 to 30 metres and may have up to 20 metres depth extension.
5) Bullion vein - This vein is located along Bullion Creek and has been traced along strike for 609 metres. The vein is 0.1 to 0.35 metre wide and occurs along a fault zone. The fault zone contains up to 50 per cent green altered volcanic fragments generally up to 5 centimetres in size. Erratic gold values occur in discontinuous quartz lenses. Post-quartz vein faulting has resulted in coarse barren quartz fragments in a matrix of green chloritic gouge. The vein has been defined on two underground levels.
6) Summit vein - This vein is located northwest of the Southwest vein and consists of parallel narrow quartz lenses from 0.07 to 0.33 metre wide within an 11 metre wide zone. High gold values were obtained from this vein.
7) Camp vein - Not located.
8) CC #1 and CC #2 veins - These veins are parallel to and a short distance south of the Georgia vein. The CC #1 vein consists of quartz veins, stringers and boxworks and is sparsely mineralized. The CC #2 vein comprise stringers and lenses of massive pyrite, sphalerite and galena in a quartz gangue. Both veins are approximately 100 metres long and up to 1.5 metres wide. Low gold values were obtained from both veins.
9) Pond vein - This vein consists of a wide zone similar to the Main vein and is comprised of zones of siliceous material separated by sericite-altered schists. The vein strikes 320 degrees and has been traced for 100 metres where it is cut off by a fault to the northwest and pinches into small quartz stringers to the southeast. Low gold values were obtained from a trench.
10) Cobbett vein - This vein parallels the Southwest vein and is comprised of a wide zone of quartz and calcite with sparse sulphides. Stringers of pyrite, galena and sphalerite striking into and along the Cobbett vein contain silver values. The vein occurs over a distance of 90 metres with widths up to 3 metres.
11) East and East Bob veins - East of the Bullion vein, a number of short discontinuous quartz lenses occur. The East vein consists of three, possibly four short discontinuous veins, generally less than 20 metres in length, some of which carry gold values up to 102.84 grams per tonne. Individual lenses vary from 0.09 to 0.6 metre width. The East Bob vein is a quartz vein or stringer 10 metres long and 0.1 to 0.2 metre wide. Gold values over 34.28 grams per tonne were obtained (Assessment Report 8547).
12) Zinc and Granodiorite veins - These veins exhibit similarities in mineralogy and mode of occurrence but occur a distance from one another. Both are sphalerite-rich zones within sericite schist alteration zones generally near or contiguous to a granodiorite dyke. The Zinc vein is a zone 0.12 to 1.1 metres in width outlined over a length of 25 metres. The Granodiorite vein is a zone 250 metres in length and generally 0.25 to 0.4 metre in width. It parallels a granodiorite dike and shows spotty gold values except in Bullion Creek where several samples returned 9.25 to 22.41 grams per tonne gold (Assessment Report 8547). Both veins have low lead values and pyrite may form up to 50 per cent of the sulphide component.
The Georgia River mine, staked in 1910, has been developed by various underground workings and five adits. In 1937, 454 tonnes were mined, producing 10,233 grams of gold, 12,752 grams of silver, and 3312 kilograms of lead.
The Bullion vein has unclassified reserves of 5619 tonnes grading 4.18 grams per tonne gold and 10.28 grams per tonne silver (Northwest Prospector Miners & Developers Bulletin, May/June 1989). Total combined (measured, indicated, inferred) reserves at Georgia River reported in 1989 were 290,272 tonnes grading 28.7 grams per tonne gold (George Cross News Letter May 11, 1989). Drill indicated reserves reported in 1995 were 272,130+ tonnes grading 27.7 grams per tonne gold (George Cross News Letter No.118 (June 20), 1995).
Reserves from Exploration in British Columbia 1995, Table 6, page 103:
VEINS YEAR CATEGORY TONNES GRADE (grams per tonne)
Southwest 1981 Drill Inferred 21 486 15.64 18.36
Southwest 1988 Drill Inferred 68 974 19.51 20.41
SW Zone 1 1989 Drill Inferred 76 356 17.73 18.67
SW Zone 2 1989 Drill Inferred 31 227 48.76 20.41
Southwest 1989 All 276 377 27.63 20.91
Southwest 1995 Drill Inferred 12 825 48.69
Bullion 1988 Drill Inferred 5 620 4.18 10.29
Aquaterre Mineral Development Ltd. drilled 19 holes, totalling 1838 metres in 1995 and 16 holes, totalling 1844 metres in 1996. The mineralization is associated with Eocene north trending dikes, and not the early Jurassic east-west dikes.
In 2003, Mountain Boy Minerals Ltd. acquired an option on the Georgia River gold property from Exchequer Resource Corp. Mountain Boy drilled 1010 metres in 20 drillholes on the property. Eight of the Mountain Boy drillholes tested the northeast trending Summit vein at its intersection with the Main vein. The best intersection came in the first hole, 22.61 grams per tonne gold and 13.2 ggrams per tonne silver over 1.07 metres (Exploration and Mining in British Columbia 2003, page 12). Twelve other holes tested the northeast trending Southwest and Bullion veins, where the Gem vein intersects them. These holes cut altered and silicified rocks but no significant gold values. The company claims an indicated resource of 130,000 tonnes grading 19.2 grams per tonne gold and an inferred resource of 53,700 tonnes grading 16.9 grams per tonne gold (Exploration and Mining in British Columbia 2003, page 12). In 2004, Mountain Boy reported that the company will not be proceeding with its option on the Georgia River property. In 2010, Auramex Resource Corp. conducted geological mapping, augmented by a helicopter-borne magnetic and transient electromagnetic survey.
Auramex Resource Corp. has released preliminary results of a 2015-16 geophysical remote-sensing survey carried out on the Georgia River mine and Georgie Girl properties. The survey comprised acquisition of synthetic aperture radar (SAR) data from the European Space Agency's Sentinel 1A satellite and was completed successfully in mid-2015. Auracle Geospatial Science Inc. carried out processing of the SAR data using its proprietary technology, and methodology and geological interpretation of the data are continuing. Preliminary interpretation of the processed SAR data indicates that structures mapped during 2010 fieldwork near the Georgia River mine are visible in the geospatially rectified image of the SAR data. The structures are visible not only on ridge crests but also under glacial and vegetative cover on the ridge sides. Two structural sets, southeasterly striking and northerly striking, host the gold-bearing mineralization at the Georgia River mine, in proximity to intrusions of the Early Jurassic Texas Creek plutonic suite. These structural sets are present throughout the property.