Siltstone breccia veined by sulphides
Virtual Museum ID: 19-D32-04
fine bedded black siltstone; irregular vein network of brown sphalerite, magnetic pyrrhotite, coarse pyrite and relatively minor quartz; marginal to the gold-bearing pyrite vein stockwork
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:Smithers Exploration Group (SEG)
Sub Collection:Red mountain
Virtual Museum ID:19-D32-04
Date Added to VM:2019-02-20
Sample Origin:Red mountain, NE of Stewart
Specific Site:0022 Crosscut
Datum:09 (NAD 83)
Primary Features:Siltstone breccia veined by sulphides
Primary Mineral Formula:S^2-
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:Stuhini Group/Hazelton Group
Geological Period:Upper Triassic/Lower Middle Jurassic
Geological Terrane:Stikine, Plutonic Rocks
Minfile ID:103P 086
The Red Mountain gold project is located in northwestern British Columbia, 15 kilometres northeast of the town of Stewart.
The Red Mountain property is situated at the western margin of a broad, north-northwest trending volcano-plutonic belt composed of the Upper Triassic Stuhini Group and the Lower-Middle Jurassic Hazelton Group. This belt has been termed the "Stewart Complex" by Grove (1986) and forms part of the Stikine Terrane. To the west, the Stewart Complex is bordered by the Eocene Coast Plutonic Complex. Sedimentary rocks of the Jurassic-Lower Cretaceous Bowser Lake Group overlay the complex in the east.
Red Mountain, an extensive gossan located between Bromley Glacier and Cambria Icefield, is underlain by pyroclastic and sedimentary rocks of the Hazelton Group (Unuk River and Salmon River formations) which have been intruded by Middle Jurassic as well as Early Tertiary stocks and dike swarms. The younger intrusive sequence forms part of the Coast Plutonic Complex.
The portion of the property located east of Bromley Glacier is underlain by Lower Jurassic Unuk Formation clastic sediments, volcanic breccias, crystal and lithic tuffs, limestones and cherts. Rocks of the Lower-Middle Jurassic Salmon River Formation, a sequence of fine to coarse grained clastic sediments, limestones, rhyolites, and crystal and lithic tuffs, are exposed west of Bromley Glacier.
Stratified rocks occupy the ridges and the southern and northern slopes at Red Mountain and consist of intermediate pyroclastic rocks (finely banded, waterlain ash and dust tuffs, coarse ash tuff, lapilli tuff, volcanic agglomerate and crystal tuff), finely banded, partly carbonaceous argillites and tuffaceous sediments, and cherts. The strata generally strike northwest and dip steeply towards the southwest, but strike and dip can be locally highly variable, which appears to be the result of doming by the hornblende-feldspar porphyry (Goldslide Intrusion) and satellite intrusions.
A hypabyssal, hornblende-plagioclase porphyritic granodiorite to diorite intrusion (Goldslide Intrusion) occupies the cirque as well as the western and eastern slopes of Red Mountain. A wide contact zone occurs between the volcano-sedimentary package and the intrusion. This zone is strongly brecciated and contains argillite and/or pyroclastic rock fragments within an intrusive matrix. Quartz stockwork is locally developed within the border phase of this intrusion. Weak to intense silicification, sericitization and propylitization are associated with these quartz stockwork zones. An extensive zone of pyritization and sericitization surrounds the Goldslide Intrusion and is responsible for the gossanous appearance of Red Mountain. Grove (1986) assumes a Middle Jurassic age for this intrusion and correlates it with the Texas Creek Plutonic Suite (Assessment Report 20971).
The Goldslide Intrusions underlying Red Mountain have been segregated into two phases, Goldslide and Hillside. Both phases have dioritic compositions. The Hillside Porphyry occurs near the summit of Red Mountain and is a medium-grained hornblende and plagioclase-phyric porphyry. The Hillside porphyry contains rafts of sedimentary rocks. The Goldslide Porphyry is a hornblende-biotite quartz porphyry intrusion underlying most the of the Red Mountain cirque. The Goldslide rocks have been noted to cross-cut the Hillside Porphyry, suggesting the Hillside Porphyry is the older phase (Assessment Report 35505).
A granodioritic to quartz monzonitic intrusion (Erin stock) is exposed at the southern tip of Red Mountain and appears to continue south under Bromley Glacier onto Lost Mountain. The stock and associated aplitic dikes intrude a sequence of thinly bedded argillites, calcareous sediments and intermediate pyroclastics. The sediments have been extensively skarnified and hornfelsed. The stock itself is cut by a number of fine grained basaltic dikes. An Early Tertiary age has been indicated for this intrusion (Grove, 1986) which may be part of the Alice Arm or Hyder Intrusion stocks. Several sets of dikes cut the sediments and pyroclastic rocks and comprise potassium feldspar porphyry, microdiorite and lamprophyre.
The rocks of the Unuk River Formation underlying Red Mountain occupy the eastern limb of the north-northwest trending Bromley Syncline, the axis of which passes immediately west of the property. Subsequent deformation is mainly characterized by simple displacement along strike-slip faults and reactivation of older faults. At Red Mountain, there are two main conjugate sets of fault and fracture zones, north-northeast and north-northwest, and east-northeast and east-southeast. All of these structural trends are associated with alteration and sulphide mineralization. Subhorizontal to shallow dipping structures occur in the eastern half of Red Mountain.
Red Mountain is characterized by an extensive gossan, covering about 12 square kilometres, which has attracted exploration activities for porphyry molybdenum-type targets in the 1960s. The molybdenite mineralization is controlled by northerly trending fractures along the northern and southern contacts of the Erin stock (see McAdam Point, 103P 220 and Goldslide Creek, 103P 221).
Several gold showings were discovered in 1989 at Red Mountain, all of which are spatially related to the contact of the Goldslide Intrusion with the surrounding sedimentary and pyroclastic rocks. The mineralization is structurally controlled and occurs in the intrusion as well as in the surrounding pyroclastics and interbedded sediments (Assessment Report 20133).
Red Mountain is a porphyry-related hydrothermal gold system. Gold mineralization is associated with, and partially hosted within, an early- to mid-Jurassic multiphaseintrusive complex, with associated volcanic and volcaniclastic rocks and sediments. Many gold mineralized zones occur on the property, including five mineralized zones with established resource estimates. The mineralized zones have been folded and are often separated by dip-slip fault zones. Mineralization can vary in orientation from shallow to steeply dipping and are generally tabular. The Marc, AV and JW zones range in widths from one metre to 40 metres, averaging about 16 metres in thickness. Gold and silver mineralization is associated with stockworks, disseminations and patches of coarse-grained pyrite, surrounded by a pyrrhotite/sphalerite halo. Alteration facies includes strong quartz-sericite alteration.
The Marc zone represents the most significant gold occurrence encountered and is located south of Red Mountain summit. Drilling has defined a well-mineralized zone up to several tens of metres in thickness along a strike length of 350 metres and a downdip extension of 100 metres. The mineralization is exposed at the base of a vertical cliff and extends at surface for about 30 metres along strike with a width varying from 3 to 20 metres.
The Marc zone is a transitional-type gold deposit with some skarn-type affinities and is associated with the contact between the Goldslide Intrusion (hornblende-plagioclase porphyry) and adjacent interbedded sedimentary and andesitic pyroclastic rocks of the Unuk River Formation. The Marc zone mineralization consists of a number of discrete lenses which are closely associated with the brecciated contact (intrusive breccias) between a sequence of interbedded argillites, tuffaceous sediments and intermediate pyroclastic rocks (dacitic ash, lapilli and crystal tuffs) and the hornblende- plagioclase porphyritic intrusion. The morphologies of the mineralized lenses are controlled by these zones of (intrusive) brecciation, strong fracturing, and, to a minor extent, shearing along the intrusive contact.
Hydrothermal alteration consists of strong to pervasive sericitization, moderate to strong pyritization, moderate chloritization, and moderate silicification. Moderate to strong potassic alteration as well as albitization occur locally.
The Marc zone mineralization typically consists of densely disseminated to semimassive pyrite replacement (up to 30 per cent) within a dark grey to black matrix and/or pyrite stringers and veinlets. Varying amounts of pyrrhotite and minor chalcopyrite, arsenopyrite, galena and tetrahedrite are associated with the pyrite. High gold values are usually associated with the semimassive, coarse grained pyrite aggregates but also occur within a stockwork of pyrite stringers and veinlets. Specks of native gold were noted only in one instance within a small quartz vein (Assessment Report 20971). Native gold as observed in polished thin sections occurs as sporadically distributed threads, interstitial pockets and partial networks within pyrite as well as molded on to the periphery of pyrite fragments within the gangue and altered wallrock. Lead, silver, gold, antimony and bismuth tellurides are associated with or contain native gold and electrum. Dark reddish brown sphalerite occurs peripheral to the gold mineralization, with zinc values being commonly inversely correlated with gold values. The most significant drill intersections in the Marc zone was a core interval of 55.5 metres grading 12.08 grams per tonne gold and 53.91 grams per tonne silver (Assessment Report 20971).
Small quartz veinlets carrying up to 5 per cent galena and light yellow, honey-coloured sphalerite cross-cut the Marc zone mineralization and represent a younger phase of mineralization. Numerous post-mineralization faults and fractures with variable orientations transect the Marc zone sequence with offsets less than 40 metres.
A silver-rich sphalerite zone with associated anomalous gold, copper and lead was intersected in holes drilled up to 200 metres vertically above the Marc zone style mineralization. Values obtained range up to 0.58 gram per tonne gold, 69.22 grams per tonne silver, 5.6 per cent zinc, 0.47 per cent lead and 0.06 per cent copper over 9 metres of core length. This sphalerite zone appears to be related to the Marc zone mineralization by zonation (Assessment Report 20971).
In 1988 and 1989, the Red Mountain property was staked by Wotan Resources. In 1989, the Red Mountain property was optioned to Bond Gold Canada Inc. Lac Minerals Ltd. acquired the ground when Bond Gold Canada Inc. was purchased in 1991 and exploration was continued at an accelerated rate (Lac Minerals Ltd.). The Marc and Brad zones were discovered and drill tested (Marc - 3623 metres in 21 holes; Brad - 1107 metres in 6 holes). Geological mapping, trenching, rock geochemistry and 5220 kilometres of an airborne geophysical survey were also completed. In 1990, continued evaluation of Red Mountain by Lac Minerals consisted of diamond drilling (13,350 metres on Marc zone and geophysical targets), ground geophysics, geological mapping, and rock geochemistry; a baseline environmental study was also initiated. In 1991, Lac Minerals completed diamond drilling of the Marc zone (2628 metres in 11 holes), geological mapping and rock geochemistry. In 1992, a survey program was conducted by Lac Minerals Ltd. on the Red Mountain and Sarah properties. The Red Mountain program consisted of detailed surveying and establishment of a semi-permanent northwest-trending grid over the main Marc zone gold mineralization. Additional, less detailed survey was conducted over the remaining portion of Red Mountain. Surrounding claims, including the Sarah property, were surveyed for future detailed aerial photography. At the completion of the 1992 program, 102 drillholes totalling almost 24 kilometres of drill core was completed and two new zones were identified (AV and IW zones). A resource of 2.5 million tonnes grading 12.8 grams per tonne gold and 38.1 grams per tonne silver was calculated in all categories using a minimum grade of 3 grams per tonne over a minimum width of 3 metres. In light of these results a major underground and surface exploration program was initiated in 1993. In 1993 and 1994, the exploration program's main purpose was to increase definition of the known zones and explore for more potential. A total of 76.5 kilometres was drilled in 304 diamond-drill holes from surface and underground, and 1315 metres of underground development was completed. This resulted in undeniable proof towards the continuity of the three ore zones and the discovery of a fourth, the 141 zone. The property was owned by Barrick Gold Corp. as a result of its September, 1994 take-over of Lac Minerals Ltd.
Mine development and environmental baseline studies were initiated in 1993 through late 1994. The environmental baseline study was conducted by Rescan Environmental Services Ltd. throughout 1994. The purpose of the study, and ongoing studies, was to test the subaqueous environment of Kitsault Lake for potential disposal of mine tailings. The Red Mountain project was put on hold by Barrick Gold Corporation, following the acquisition of Lac Minerals. From 1989 through 1994, a total 406 surface and underground boreholes were drilled on the property, including 368 drilled within the limited footprint area of the Marc, AV, JW, AV-JV Tails and 141 gold-silver zones. The project was sold to Royal Oak Mines in August 1995. In 1996, Royal Oak Mines Inc. conducted surface and underground drilling as well as driving a 300 metre underground extension. A new zone of mineralization, the SF, located at depth to the northwest of the previously known zones is reported. The drilling showed that the JW Zone was truncated to the north by faulting or folding. However, drilling intersected Red Mountain-type mineralization closer to the valley floor within the SF zone 91 metres below and 91 metres due north of the JW zone. The existing reserve is 2.77 million tonnes assaying 8.98 grams per tonne gold and containing 25 million grams of gold (Royal Oak Mines Inc., Annual Report 1996). They also estimate a resource of 1,921,680 tonnes grading 9.8 grams per tonne gold (Information Circular 1998-1, pages 16, 19).
North American Metals, owned by Wheaton River Minerals Ltd. agreed to buy the property in December 1999. Mineralized material at Red Mountain as published in Royal Oak's 1998 annual report totals 12,009,300 tonnes grading 2.54 grams per tonne gold. A technical evaluation completed by Wheaton River indicates that a higher grade core of the deposit could be economically extracted, mining about 700,000 tonnes grading 12 grams per tonne gold, and recovering about 7,776,000 grams gold. A geostatistical evaluation carried out by Wheaton River indicates that no further drilling may be necessary for ore reserve estimation of the higher grade core. Diamond drilling on the property has totalled 127,000 metres and 2000 metres of underground workings have been excavated, including a 1000 metre production-sized decline.
In 2000, upon acquisition of the project from Price Waterhouse Coopers, North American Metals Corporation completed a comprehensive review of the project and validation of the geological and environmental database. Several new technical studies were carried out leading to the creation of a revised resource model. Seabridge Gold Inc. acquired the Red Mountain Project from North American in February 2002. In January 2003, Seabridge Gold Inc. commissioned Steffen Robertson and Kirsten (Canada) Inc. to complete monitoring activities and field investigations related to developing a final reclamation plan. The objectives of the study were to build on previous project work, and included collection and analysis of seeps, crib drainage and underground water samples, monitoring of dump weathering, monitoring of water levels in the underground workings, determining the feasibility of collection ditches to monitor dump flows, completing an inventory and evaluation of buildings and equipment, and documenting general site conditions.
In 2012, on behalf of Banks Island Gold Ltd. a National Instrument 43-101 compliant preliminary economic assessment study dated June 14th 2012 was prepared by independent consultants. In four zones (Marc, AV, JW, 141), total inferred resources are 807,000 tonnes grading 5.4 grams per tonne gold and 10 grams per tonne silver; total measured and indicated resources are 1,611,000 tonnes grading 8.4 grams per tonne gold and 38 grams per tonne silver (Press Release - Banks Island Gold Ltd., June 18, 2012).
In 2013, Banks Island Gold Ltd. drilled 3 holes totalling 681 metres in the Marc Zone. All holes intersected a sequence of sericite altered crystal tuff overlying a strongly sericitized hornblende-plagioclase porphyry. The contact between these units is marked by a heterolithic breccia. Gold and silver mineralization is associated with disseminated pyrite in microveinlets, as medium to coarse grained aggregates in quartz veins, and semi-massive to massive veins. Bright red sphalerite is noted as fine to medium grained aggregates in quartz veins, and commonly rimming pyrite grains. Pyrrhotite occurs intermittently as disseminations and fine to medium-grained masses in quartz veins. Highlighted drill results include 71 metres (estimated true width of 63.8 metres) grading 4.4 grams per tonne gold and 16 grams per tonne silver (drillhole RM-13-01), and 52.5 metres (estimated true width of 49.8 metres) grading 6.3 grams per tonne gold and 16 grams per tonne silver (drillhole RM-13-03) (Assessment Report 34526).
In 2014, the Red Mountain project was optioned by IDM Mining Ltd. who drilled 12 holes totalling 2221 metres across 4 zones. Also completed in 2014 was geological mapping, rock sampling, soil sampling, channel sampling, and historic core re-logging and sampling. Glacial recession in the Cambria Zone (approximately 600 metres east of Red Mountain) revealed a broad zone of mineralization and 2 new showings were discovered: Oxlux (103P 329) and Wy Lo’oop (103P 330). These discoveries by channel sampling were targeted as part of the 2014 drill program. A third new showing called the Fridge showing (103P 331) was also discovered in 2014 by channel and rock sampling approximately 1200 metres east of the McAdam zone (103P 220) (Assessment Report 35505).
Historic core re-logging and sampling in 2014 was conducted on select drillholes of un-assayed core from the 1993 and 1994 drill programs by Lac Minerals intersecting the 141 zone. Results indicate that the mineralized trend of the 141 zone is subparallel with the Marc, AV, and JW resource area, has a strike length of at least 325 metres, and extends up to 350 metres wide. Gold is hosted in a complex assemblage of strongly altered hornblende-feldspar porphyry dikes and sills, intruding tuffaceous volcanic and sedimentary rocks. Stockworks, veins, and disseminations of pyrite and pyrrhotite correlate with gold values, commonly in areas of strong sericite alteration, potassium feldspar alteration, and silicification. Highlights from sampling the historic core include 159 metres grading 0.73 gram per tonne gold (drillhole MS93-139), 171.2 metres grading 1.05 grams per tonne gold (drillhole MS94-184), 139 metres grading 1.59 grams per tonne gold (MS94-186), and 97 metres grading 1.63 grams per tonne gold (drillhole MS94-203) (Assessment Report 35505).
In 2014, three holes totalling 678 metres were drilled in the 141 zone, intersecting a fine to medium-grained siltstone and locally the Hillside and Goldslide porphyries. Gold mineralization was noted in the black-green siltstone and in hornblende porphyry, characterized by pyrite veins and patches with local pyrrhotite. Results include 3.9 metres grading 4.7 grams per tonne gold (drillhole MC14-001), 84 metres grading 0.8 gram per tonne gold (drillhole MC14-002), and 138 metres grading 1.41 grams per tonne gold (drillhole MC14-003). Two holes totalling 883 metres were drilled in the AV Zone, intersecting the Hillside Porphyry. Gold mineralization is characterized by pyrite and pyrrhotite patches, as well as several massive pyrrhotite veins with local spahlerite and pyrite. Results include 7 metres grading 2.38 grams per tonne gold (drillhole MC14-004), and 11 metres grading 6.59 grams per tonne gold (drillhole MC14-005). Two holes totalling 107 metres were drilled in the Marc Extension Zone. Both holes intersected the Hillside Porphyry, and drillhole MEx14-002 also intersected the Goldslide Porphyry. Massive pyrrhotite, chalcopyrite, pyrite veins were noted in MEx-14-001, and both holes reported veins and patches of pyrrhotite, pyrite, and chalcopyrite. Results include 5.5 metres grading 6.16 grams per tonne gold (drillhole MEx14-001), and 4.9 metres grading 1.69 grams per tonne gold (drillhole MEx14-002) (Assessment Report 35505.
Five drillholes were completed in 2014 in the Cambria Zone. Two of these holes targeted the newly discovered Oxlux showing (see MINFILE 103P 329) and three holes targeted the Wyy Lo’oop showing (see 103P 330).
As of April 4, 2016, IDM Mining Ltd. reported a National Instrument 43-101 compliant resource update for the Red Mountain gold project. Using a 3 grams per tonne gold cut-off grade, the updated resources includes total measured and indicated resources of 1,641,600 tonnes grading 8.36 grams per tonne gold and 26 grams per tonne silver from four zones (Marc, AV, JW, 141), and total inferred resources of 548,100 tonnes grading 6.10 grams per tonne gold and 9 grams per tonne silver (Mineral Resource Update filed on www.sedar.com - May 6, 2016). IDM recently announced the results of a feasibility study for a high-grade, underground gold mine, which includes primarily bulk underground mining methods and the production of gold dore on site. The project is advancing through the provincial and federal environmental assessment processes, with comprehensive, thorough and continuing consultation with Nisga'a Nation.
The 2017 drilling program by IDM Mining Ltd. totals 50 underground drillholes completed to date (July) and are primarily resource expansion holes, testing down and updip from current reserves, as well as two holes to the north along strike from the current mine reserve. The primary objective of the expanded drilling program is to add additional years to the potential mine life by targeting near-mine mineralization from underground, as well as diamond drilling from surface, testing the surface exposure of the 141 zone (Stockwatch - July 4, 11, 2017).
Drillholes U17-1234, U17-1236, U17-1237 and U17-1239 are exploration holes targeting approximately 150 to 250 metres downdip from the current mine reserve. The holes are testing the connection between historical intercepts in the 132 and 141 zones and AV zone. Multiple mineralized zones exhibit a gentle, westerly dip and with higher grades typified by massive and disseminated coarse grained pyrite mineralization. Wide zones of gold mineralization were encountered, including 97 metres averaging 1.24 grams per tonne gold, including six metres averaging 6.27 grams per tonne gold in U17-1234. Additionally, systematic downdip step-out holes are continuing, such as U17-1241, which intersected a true width of 4.5 metres of 5.93 grams per tonne gold and 25.9 grams per tonne silver, and U17-1232, which intersected a true width of seven metres of 6 grams per tonne gold and 16.78 grams per tonne silver. One infill hole was completed, where U17-1243 intersected a true width of 14 metres at 5.37 grams per tonne gold and 14.19 grams per tonne silver.
U17-1245 was a 25-metre updip step-out from the current reserve, intersecting 12.33 grams per tonne gold and 70.9 grams per tonne silver. Downdip holes including U17-1240, U17-1242 and U17-1244 continued to intersect the mineralized structure, with current and future drilling continuing to step out exploring for higher-grade and wider areas along the mineralized horizon. Drillholes U17-1255 to 1265 all targeted the JW zone, the northernmost zone that hosts reserves and resources at Red Mountain. Ten holes were step-out, both up and downdip, and one hole, U17-1256, was an infill hole and intersected two lenses of the JW zone. Drillholes 1257, 1259, 1261, 1262 and 1264 were systematic step-out holes both up dip and downdip, as well as along strike. Drillhole U17-1262, which intersected 14.00 metres true width averaging 10.65 grams per tonne gold and 17.37 grams per tonne silver, is the farthest updip hole on this section. The zone remains open for expansion in this direction. Drillholes U17-1258, 1260, 1263 and 1265 were all step-out holes testing at least 100 metres downdip from current reserves. Drillhole U17-1258 intersected 3.75 metres true width of 8.49 grams per tonne gold and 10.43 grams per tonne silver, with wide zones of massive pyrite mineralization. All holes intersected broad zones that assay over 1.0 gram per tonne gold, similar to the 141 zone located farther to the west of the JW zone.
The SF zone is located along strike to the north of current reserves. Despite high grade, historical drilling over a wide area, there are currently no resources in this area. The SF zone is interpreted to be the fault extension of the reserves within the JW zone to the south. Significantly, drillhole U17-1252 hit the mineralized horizon 150 metres along strike from current reserves. This hole intersected a true width of four metres averaging 3.77 grams per tonne gold and 13.03 grams per tonne silver, with pyrite mineralization occurring along a sediment-intrusive contact, surrounded by a pyrrhotite/sphalerite halo. This is the typical mineralization style of reserves and resources at Red Mountain. U17-1251, 1253 and 1254 were wide-spaced exploration holes, north of the fault bounding current reserves and resources in the JW zone. U17-1253 intersected strong zones of pyrite mineralization, including 1.0 metre averaging 27.50 grams per tonne gold. U17-1254 intersected 1.0 metre of 9.67 grams per tonne gold and 17.00 grams per tonne silver. Mineralization occurs near a strongly altered contact between tuffaceous sediments and diorite porphyry, often with a zinc-rich halo, similar to the Marc/AV/JW zone style of mineralization.