The region is underlain by Upper Triassic metasedimentary rocks with some intercalated volcanics of the basal part of the Nicola Group. This sequence is overlain to the west by alkali basalt and alkali olivine basalt. The metasedimentary rocks consist of slaty to phyllitic, dark grey to black shale and siltstone and dark brown to black-weathering grey limestone and, increasing in amount up section, banded tuff, volcanic breccia and local pillow lavas.
These rocks have been folded initially about northwest trending axes and then refolded about axes subparallel to those of F1 folds at the mesoscopic scale. Whereas F1 folds have an accompanying penetrative fabric, deformation associated with F2 folding was essentially nonpenetrative, manifested as crenulation and fracture cleavages. A third phase of deformation unaccompanied by folding is recognized as easterly striking, steeply dipping fractures. Northeast directed thrust faults occur at the base of the metasedimentary assemblage and possibly within the assemblage. These faults probably formed at the same time as F1 folds and are deformed during F2 folding. Northeast striking, steeply dipping normal faults cut the volcanic terrane to the west and appear to have cut the eastern metasedimentary rocks in some areas.
The geology of the CPW deposit is typical of the metasedimentary assemblage. Dark grey siltstone and shale has been folded along northwest striking axes, in places isoclinally. Intercalated lenses of highly siliceous (probably rhyolitic) tuff occur within the sequence. Felsic porphyry dikes and sills also occur.
Gold mineralization with associated base metals occurs within quartz veins. The veins formed during and after deformation along the limbs and localized within hinge regions of mesoscopic folds. There is a suggestion that these quartz veins are also fault or shear-controlled. Mineralization consists of coarse gold, galena, sphalerite, chalcopyrite, tetrahedrite and pyrite with quartz, mariposite and ankerite gangue. Gold also occurs in limonitic pseudomorphs after pyrite within siltstone. Coarse gold visible in some quartz veins may be the product of supergene enrichment. Drilling results indicate that gold mineralization in the quartz veins is discontinuous or in podiform shoots. The veins are generally narrow but can be up to 4 metres wide. The quartz veins also cut felsic porphyry. Several zones of oxidized material, containing a small amount of reserves, have been identified and tested.
The gold-bearing quartz veins were discovered in 1933 by F. Dickson and A. Bayley. Two adits were driven on lower veins in 1938. In 1947, El Toro B.C. Mines, Ltd. conducted diamond drilling (8 holes, 793 metres) and shipped 3.6 tonnes of ore, containing 249 grams of gold, 1306 grams of silver, 46 kilograms of copper and 66 kilograms of lead.
Unclassified reserves in the Main (Madre) and LE zones are 838,160 tonnes grading 1.95 grams per tonne gold (Trio Gold Corp. Annual Report 1988). Erratically distributed free gold makes accurate estimations difficult.
Placer gold has been mined from the creeks draining Spanish Mountain since before 1921, when rich discoveries were made in Cedar Creek, on the southwest side of the present Spanish Mountain property. In 1933, gold was discovered in quartz veins on the northwest flank of Spanish Mountain. Workings on the property in 1933, which at that time was known as the Mariner claim, consisted of an opencut and trench. Prospecting and minor stripping was carried out on the property during the ensuing years between 1934 and 1938.
In 1938, the Mariner claim was optioned to the N.A. Timmins Corporation who stripped a large area of overburden and drove two short adits on the property. Of particular interest were two large quartz veins at what became known as the lower showings (at ~1200 metres elevation). These veins, 1.5 and 1.8 metres wide respectively, were reported to be sparsely mineralized with ankerite and pyrite. Both were exposed for 30 and 45 metres respectively in the opencuts. A short adit (12.8 metres) was driven into the footwall of the lower vein and an incline was driven an unknown distance down the dip of the vein. The results of this work are unknown, but in 1947 it was concluded that because the two vein-outcrops probably represented a single, faulted vein, the decline had not penetrated the vein at depth. The property appears to have been abandoned after the 1938 program.
In July 1946, eight claims, known as the Max Group, were staked in the vicinity of the 1938 adit (covering ground previously held as the Joe claims) and were transferred to El Toro B.C. Mines, Ltd. By July of 1947, El Toro had carried out a diamond drill program consisting of 792 metres of drilling in 8 holes. In October 1947, the first production from the property was recorded when four tons of handpicked ore were shipped to the Tacoma smelter. In October 1947, the claims Mariner, Mariner 5 and 6, and the Mariner Fraction were staked over the ground covered by the original 1933 Mariner claim. The relationship of these claims to the Max claim group is unknown.
There is no recorded work from 1947 to 1971. In 1971, Spanallen Mining Limited carried out a magnetometer survey over the Marnier 1-25 claims, concentrated largely between 900 and 1060 metres elevation on the Cedar Creek drainage of Spanish Mountain. The survey was inconclusive. In 1976, the Mariner II claim was staked over the historical showings by M.B. Neilson, and geological reconnaissance was carried out by N.W. Stacy, assisted by J. McMillian and M. Neilson. A few samples were collected, but assay values were low. The 1976 claim map also shows subsequent staking of the six PESO claims (PESO and PESO B to PESO F) surrounding the Mariner II claim. In 1977 and 1978, the Mariner II claim (now owned by LongBar Minerals Ltd.) and the optioned PESO (owned by R.E. Mickle) and PESO A to PESO B claims were explored by two small programs.
In 1979, Aquarius Resources Ltd. (a private company) carried out a surface exploration program on the PESO, PESO B and PESO E claims with most of the work focused on the PESO B claim. In November 1979, Aquarius Resources Ltd. along with Carolin Mines Ltd. carried out a regional assessment of the Likely area. They concluded that the Spanish Mountain property was one of economic interest and worthy of continued exploration. In 1979, the Mariner II claim was optioned to E. Schultz and P. Kutney, who contracted N.L. Tribe to prospect and sample the property. Roadcuts and old pits were excavated by backhoe along an access road which switchbacked up across the Mariner II claim. Intermittently between
1980 and 1982, physical work consisting of stripping by D-7 and D-8 bulldozers and the digging of approximately 240 metres of backhoe trenches was carried out by R.E. Mickle and Norsemont Mining Corp. This work appears to have been primarily done on old workings on the DON and Mariner II claims. Little information exists on this program since no work or reports were filed.
In 1981, Aquarius Resources Ltd. carried out a geochemical and geophysical program on the PESO claim (owned by E. Lorentsen and optioned to Aquarius) and on the PESO B and PESO E claims (owned by Aquarius). In 1982, the Marnier II claim lapsed and was re-staked in October 1982 by the Mariner Joint Venture as the CPW claim.
In 1983, Lacana Mining Corporation carried out an exploration program on the DON 1-4, Mar 1, PESO, JUL 2, MY, and Apr Fr. claims (not including the CPW claim). Work focused on the area north of the Spanish Lake road and the program found some strong gold anomalies coincident with silicified argillite, and recommended that these areas be stripped and trenched. In March 1983, Whitecap Energy Inc. optioned the CPW claim. Exploration in 1983 consisted of a soil sample survey with ten east-west, soil sample lines covering most of the CPW claim. A total of 409 samples, at a 40 metre sampling spacing, were collected. Highly anomalous gold values, up to 5100 ppb, were returned, mostly from the southwest quadrant of the claim. Aquarius Resources Ltd. also active in the area in 1983, carried out a small program on the PESO B. Work consisted of 100 metres of trenching in 3 trenches and some limited soil sampling.
In 1984, JMT Services Ltd. optioned the PESO property and carried out a small geochemical program. Later in 1984, Hycroft Resources and Development Ltd. optioned the PESO and DON claim groups (DON 1-4, PESO, JUL 2, MY, Mar 1-3, Fe 1, April Fr., De 2-3, and Nik claims) and carried out a combined trenching and soil sample survey. They identified a northwesterly trending zone of anomalous gold values in soils on the PESO claim, along with elevated gold values in rock samples from trenches. During the summer of 1984, Mt. Calvery Resources Ltd. optioned the claims surrounding the CPW claim and carried out a regional reconnaissance that included prospecting, geological mapping, and rock and soil sampling. In late July Mt. Calvery discovered free gold within vuggy shale and siltstones in the ‘Madre’ area of the CPW claim. This, along with anomalous gold values in rocks, identified this area as having potential to host a replacement-type of gold mineralization and opened up the possibility of a low-grade bulk tonnage deposit. As a result, in August 1984, Mt. Calvery Resources optioned the CPW claim from Whitecap Energy Ltd. and the Mariner Joint Venture. Later that fall in November, Mt. Calvery Resources and Teck Corporation entered into an agreement through which Teck would fund Mt. Calvery’s exploration in the Spanish Mountain area by purchasing shares in Mt. Calvery. Welcome North Mines was to be the operator. Exploration under the joint venture began in the fall of 1984, with the first of what would eventually become a three phase program over the next 2 years. The program in 1984 consisted of 2225 metres of trenching including and/or subsequent to 45 trenches and pits, 467 metres of diamond drilling in 10 holes (MD-1 to 10) and 589 metres of reverse circulation drilling in 10 holes (MR-1 to 10).
In June 1985, Mt. Calvery began a follow-up program in the Madre and LE areas consisting of 600 metres of excavator trenching and sampling, and 655 metres of rotary percussion (reverse circulation) drilling in 7 inclined holes in the Madre area and 1 hole in the LE area. Encouraged by the first phase of trenching and drilling, Mt. Calvery undertook a second phase of exploration during August and September of 1985. The objectives of which were to explore the Madre zone by grid drilling along the mineralized trend to the northeast and southwest, and to test the strike extensions of the LE and several other recently discovered mineralized zones parallel to and adjacent to the Madre. This comprehensive phase II program included approximately 820 metres of backhoe trenching and sampling (550 1-metre channel samples) and 2521 metres of rotary percussion (reverse circulation) drilling in 29 inclined holes. In August, 1985 Mt. Calvery Resources optioned the PESO property (DON 1-4, PESO, JUL 2, MY, MAR 1-3, FE 1, APRIL FR., DE 2-3, and NIK claims) from Hycroft Resources and Development Ltd. in order to fully evaluate the southern extension of the Madre zone. During October-November 1985, Mt. Calvery Resources carried out a third phase of exploration, this time spread over both the CPW and PESO claims. Two diamond-drill holes were drilled on the CPW claim to twin existing rotary holes (MR-35 was twinned by MD-48/MD-11, and MR-13 was twinned by MD-49/MD-12), and five holes (MD-50/MD-13 to MD-54/MD-17) tested the extension of the Madre zone on the PESO claim. The funding was again provided by Teck Corp., and Welcome North Mines was the operator. The twinned diamond-drill ‘core’ holes returned lower assays than did the original rotary ‘chip’ holes. This was ascribed to the ‘nugget-effect’ of coarse particles of gold that was amplified by the smaller core size. The drilling on the PESO claim [option] extended the Madre zone approximately 100 metres to the southwest where it was found to be terminated by a post-mineralization normal fault.
In June 1986, Mandusa Resources Ltd. optioned a portion of the current Spanish Mountain property (not including the CPW claim which was at the same time optioned to Pundata Gold Corporation). Mandusa proceeded with an extensive exploration program during the summer of 1986, largely focused on the PESO and DON claims. Work consisted of geological mapping, an induced polarization (IP) survey, and percussion drilling on both the PESO and DON claims. Geological mapping, along with the IP survey identified a broad graphitic shear zone extending westerly from Spanish Lake. Percussion drilling on the DON claims, which consisted of 356.62 metres in 6 holes traced part of a shear zone caring anomalous gold values. Percussion drilling on the PESO claim identified one area, called the “green pit”, in which anomalous gold geochemistry is associated with an apparent horizontal structure related to shearing and /or fracturing.
In 1986, Pundata Gold Corporation optioned the CPW claim from D.E. Wallster and optioned the PESO group (PESO, DON 1-4, MY 1, MEY 1-2, JUL 2 claims) from D.V. Mickle the following spring. During 1987 and early 1988, Pundata proceeded to embark on a major and comprehensive exploration program which involved a complete re-evaluation of the Spanish Mountain property. Work included 37 diamond-drill holes (3273 metres), 15 percussion (reverse-circulation) holes (1237 metres), trenching (848 metres), geological mapping, collection and analysis of 5350 samples, metallurgical testing of 11 samples, and preliminary resource estimates. The primary focus of the Pundata 1987-88 program was to determine the grade and tonnage of the Madre Zone including testing for its extensions and to evaluate other mineralized zones, such as the LE Zone. The bulk of the work was carried out in the Main Zone. Diamond drilling confirmed the highly disruptive nature of the rocks in this area and outlined the presence of two subordinate splay faults of the Madre Fault. These faults trend through the Main Zone at about 060 degrees and dip steeply to the northeast and were (at least the northernmost faults) found to contain zones of low-grade gold mineralization. Exploration on the adjacent LE Zone was more limited, with 42 metres of trenching, along with 267 metres of HQ diamond drilling (3 holes) and 157 metres of NQ diamond drilling (2 holes). During this period limited rock, soil and chip sampling, trenching and drilling were carried out on claims surrounding the CPW with most of this work directed at the PESO and DON claims. Reverse-circulation drilling on the DON claim was targeted to intersect mineralization exposed in Trench A.
In 1992, Eastfield Resources Ltd. reassembled the Spanish Mountain property with option agreements with several individuals. During 1992, Renoble Holdings Incorporated (subleasing from Eastfield) mined and stockpiled 635 tonnes from a small open pit on the M1 vein in the Madre Zone (CPW claim). This material was processed in two separate mill runs: 318 tonnes were sent to the Premier mill and 105 tonnes were sent to the Bow Mines (Greenwood) mill. Schroeter estimates 1431 grams (46 ounces) of gold were recovered from the Premier mill and 3266 grams (105 ounces) of gold were recovered from the Greenwood mill.
In 1993, Cogema Canada Ltd. optioned the property from Eastfield and carried out an extensive trenching and sampling program over two years which consisted of digging 30 trenches, and collecting approximately 900 rock/channel samples. The trenching was largely concentrated in areas on the CPW claim (with a minor amount on the north end of the PESO claim) where previous work had indicated broad-scale disseminated mineralization in shaley siltstone. During this period Renoble Mines set up a placer gold washing plant to mine gold contained in soils on the CPW claim area and covered by a placer claim.
Consolidated Logan Mines Ltd. optioned the Spanish Mountain property from Eastfield in 1995 and in turn optioned it to Cyprus Resources Ltd. in February 1996. In the following year Cyprus carried out an exploration program for a bulk-mineable, disseminated gold target on the property. Work consisted of 2590 metres of semi-continuous trenching and 76 metres of test pit trenching in a series of 8 opencuts oriented perpendicular to the slope of Spanish Mountain and spaced 200 metres apart. Cyprus Canada's operations were, at this same time being shut down, and the property was consequently returned to Eastfield. In 1997, Eastfield Resources Ltd. was reorganised, through a Plan of Arrangement, into Eastfield Resources Ltd. and Wildrose Resources Ltd. A 100 per cent interest in the Spanish Mountain property was allocated to Wildrose Resources Ltd.
In 1999, Imperial Metals Corporation optioned the Spanish Mountain property from Wildrose to determine if low-grade gold-mineralized sedimentary rock on the property could be used as millfeed “sweetener” for their Mount Polly Mine copper-gold concentrator located 15 kilometres away. Metallurgical testing was carried out in late 1999 on samples from the Madre and LE zones. Five prospective areas on the property were chosen for evaluation: the Madre, LE, M5, 103 and Dodge zones. The initial objective on the property was to determine if any of the areas had consistent, elevated gold values (greater than 1 gram per tonne). Each site was percussion drilled using an air-track drill in a grid-like, blast pattern. A total of 464 holes were drilled to a maximum depth of 13 metres for a tally of 2542 metres drilled. The LE Zone produced the best analytical results; 107 of 201 samples collected graded better than 1 gram per tonne and 153 samples graded better than 0.5 gram per tonne. The area of the final blast encompassed 103 of these holes with an average assay of 2.20 grams per tonne gold. The LE zone blasted well, producing a fine muck pile that was amenable to screening. This was in contrast to the M5 Zone which produced large angular blocks and much fly rock, with the result that no further work was done with the material from the M5 Zone. The LE Zone muck was screened into four size fractions with the fine fraction (-3/8”) being trucked to Mount Polley for further grinding and processing. A total of 64 truckloads, weighting 1908 dry tonnes, were trucked to Mount Polley during the period July 24–29, 2000. The average gold content of this material was determined by mine staff to be 3.02 grams per tonne. The material was fed into the mill at a rate of approximately 50-100 tonnes per hour over a 2 day period, comprising a maximum of 10 per cent of the total mill feed. Robertson (2001) reports that gold recovery in the milling circuit was good; however, boosting the amount of pyrite pulled off to increase gold recovery in the flotation circuit had an adverse effect on the copper concentrate grade. As a result it was concluded that the Spanish Mountain material was not suitable for blending with the Mount Polley mill feed owing to the fact that the added precious metals credits were more than offset by the reduced copper grade.
Consolidated Logan Mines Ltd. has an option on the property from Wildrose Resources Ltd. Imperial Metals optioned the property from Wildrose in January 2000. Imperial must spend $500,000 over 5 years. Skygold Ventures Ltd. entered into an option agreement with Wildrose Resources in 2003.
Exploration on the Spanish Mountain property started in 2003 when Skygold Ventures Ltd. funded a soil geochemical and geophysical programme. The 2003 work included establishing 30 kilometres of grid (23 kilometres cut), collecting and analyzing 1479 soil samples, completing 23 kilometres of induced polarization survey and brushing out the extensive, but overgrown, road system. This work was conducted by Mincord Exploration Consultants Ltd. The soil sampling revealed large areas of anomalous gold-in-soil, which were associated with anomalous arsenic and molybdenum values.
An extensive exploration programme was conducted by Mincord in 2004, again funded by Skygold Ventures. This programme consisted of excavator trenching, reverse circulation drilling and mapping. The excavator trenching was conducted in June, with mapping and sampling of the trenches continuing into September. A total of 30 trenches were dug, to a total length of 2419 metres, which targeted the gold-in-soil and geophysical anomalies of the 2003 programme. Trench mapping showed that many of the resistivity breaks of the survey reflected geological contacts between black argillite and competent sericite-carbonate altered coarser units (wackes and debris flows). Trench sampling revealed a number of areas of gold mineralization both in apparently unaltered argillaceous rocks as well as in local discrete quartz veins.
In October and November of 2004, a reverse circulation drilling programme was conducted on the property to follow up on the trench results and other soil and geophysical anomalies from 2003 and earlier. A total of 2503.65 metres was drilled in 34 holes in a number of areas both within the areas of known mineralization on the CPW claim and on new targets up to 1.3 kilometres away. Some 55 intersections greater than 1 gram per tonne gold were obtained from the drilling, which included discoveries up to 1 kilometre from the CPW claim. The most important result from the drilling was the discovery of a northern extension to the LE Pit mineralization in holes 04SPRC-216, 221 and 229. Each of these holes returned long intersections of consistent 1-2 grams per tonne gold mineralization hosted in apparently unaltered argillite and siltstones. This area is presently called the Central Main Zone. The 2004 drilling also discovered new zones of mineralization far from the previously known zones. Hole 04SPRC-210, collared 700 metres west of the LE Pit, returned 10.67 metres of 1.05 grams per tonne gold, while 04SPRC-212, 300 metres further west, returned 4.56 metres of 1.16 grams per tonne gold. This second hole is regarded as part of the McKeown Placer Area. A number of holes were also drilled in the Madre Zone area to search for mineralization reported from the Mt. Calvery and Pundata drilling. Results were disappointing, probably due to the erratic style of the high grade mineralization in the Spanish Mountain area.
In 2005, Mincord conducted two programmes of reverse circulation drilling on new targets away from the new known mineralization. The most significant discovery of the first programme was in hole 05SPRC-250, which intersected 56.39 metres of 1.17 grams per tonne gold, 320 metres north of the LE Pit. The second reverse circulation drill programme of the year produced a result of 137.77 metres of 1.16 grams per tonne gold from hole 05SPRC-310, which was located near Spanish Creek, 780 metres north of the LE Pit, in what is now referred to as the North Main Zone. In the autumn of 2005 the Don claims area south of Spanish Creek was mapped and sampled. The Dodge and 103 Zones of the 1999 Imperial Metals blast hole programme lie within this area. A number of > 1 grams per tonne gold in rock areas were discovered; some new, some rediscoveries of mineralization noted from the Pundata work and earlier. The 2003 soil grid was also extended to the west in the area south of Spanish Creek. Also during 2005 Skygold Ventures carried out diamond drilling in the LE Pit area (now referred to as the Main Zone) and to the north, confirming the continuity of the mineralization there. Thirty-five holes, totaling 7746.25 metres were drilled between July and November.
A total of 323 diamond-drill holes have been completed by Skygold Ventures from 2005 to 2008 representing a total of 74,797 metres of drilling. In March 2009, Skygold Ventures Ltd. released an updated resource estimate based on drilling from 2005 to 2008. They reported 102.3 million tonnes combined Measured and Indicated Resources grading 0.785 gram per tonne gold and 11.65 million tonnes Inferred Resources grading 0.787 gram per tonne gold, both based on a 0.50 gram per tonne gold cut-off grade (Press Release Stockwatch March 18, 2009).
In 2012, Spanish Mountain Gold Inc. released results from an ongoing infill drilling program. Several holes returned gold values around one gram per tonne, including drillhole 12-DH-1042 with a 3 metre length at 7.58 grams per tonne gold (V STOCKWATCH, May 1, 2012).