Placer gold provided the first exploration interest in the area starting in the mid to late nineteenth century, with deposits on the Wild Horse River proving large and profitable. Anecdotal information suggests at least 1.5 million ounces (46.7 million grams) of gold have been recovered; however, no corresponding lode deposits of any size have been discovered, suggesting the gold potential of the Wildhorse Creek Area has undeveloped potential.
The Dewdney Trail Property is located upstream from placer deposits in Wildhorse Creek and may host the source of the placer gold.
Exploration on the Dewdney Trail Project prior to its acquisition by SG Spirit Gold Inc, and subsequent option to PJX in 2010 consisted of: (i) prospecting; (ii) follow-up (confirmatory) soil geochemistry; (iii) rock geochemistry; (iv) trenching, (v) data compilation into GIS format; (vi) geological mapping; and (vii) small drill programs on three of the five showings located on the Dewdney Trail Project: Tac, Jack Leg and Dew Drop. The Spirit and Lewis showings have never been drilled.
In October, 2010, PJX contracted Aeroquest Airborne to conduct detailed 75 m line-spacing airborne geophysical (Electromagnetic and Magnetic) test surveys over the 5 showing areas of the Dewdney Trail Property.
In December, 2010, Robert Thompson (PGeo) completed an NI 43-101 Technical Report on the Dewdney Trail Property for the Company.43-101 Report
The Dewdney Trail Project comprises 36 contiguous mineral tenures covering approximately 13,043 ha located in the western Rocky Mountains of southeastern British Columbia adjacent to the Rocky Mountain Trench. It is accessible using two major logging road systems off highway 93 where it parallels the eastern margin of the Kootenay River.
The town of Kimberley is located 32 km to the west on the far side of the Rocky Mountain Trench; the town of Cranbrook is located 29 km to the south west; and the village of Wasa, is 10 km to the west on the eastern margin of the trench (see Figure 4-1).
Figure 4-1: Location of the Dewdney Trail Project mineral tenures in the western Rocky Mountains of southeastern British Columbia, Canada.
The towns of Kimberley and Cranbrook are the nearest major supply centres where material and services adequate to explore the Dewdney Trail Project can be found. Infrastructure resources are excellent and readily available. The Dewdney Trail Project is within a few kilometers of the hydroelectric grid. The region has a long history of mining, hence personnel with heavy equipment, exploration and mining experience are available.
The climate is benign, with agreeable spring-summer-fall seasons and a temperate winter that sees relatively limited snow accumulations at lower levels, although accumulations may be substantial at elevation. Work in subalpine and alpine regions is seasonal, limited to June through mid October. At lower elevations the field season extends from late April until November.
The Dewdney Trail Project is underlain by Mesoproterozoic Purcell strata belonging to the Fort Steele, Aldridge, Creston and Kitchener formations. In general, the lower portion of the Aldridge Formation on the property is dominated by variably dolomitic siltstone, silty dolomite, and quartzite; by contrast, the upper portion is more argillaceous and siliceous (quartzose), is not dolomitic or calcareous, and contains proximal, turbiditic, quartz-wackes. The transition from Aldridge to Creston formations is gradational, via grey and black siliceous argillite to grey- and green-weathering phyllite and quartzite. The appearance of shallow-water sedimentary structures signifies a change in depositional environment from basin-slope to platform (Höy, 1993), that is, from rift-fill to rift cover (sag) sequences.
A 75 to 100 m thick succession near the top of the Aldridge formation consisting of immature quartz-wacke (sandstone) is pervasively altered and fractured. It contains pockets of visible gold as well as anomalous gold values throughout; of particular interest are two showings, Spirit and Lewis, where the quartzite is host to important gold anomalies. The succession has a uniform, steep, westward dip, and is sandwiched between less permeable and less brittle argillaceous map units; hence, its susceptibility to (hydraulic) fracturing allowed it to act as a fluid conduit, thereby explaining the density of fractures, pervasiveness of alteration, and anomalous gold content. The source(s) of fluids include (i) hydraulic jacking associated with thrust displacement and (ii) fluid expulsion and/or circulation driven by the emplacement of Late Cretaceous magmas.
The Spirit and Lewis showings hold the greatest opportunity for economic return; hence, they are the focus of the Technical Report and analysis.
The key economic driver for the Spirit Showing is target size: 100 m by 6000 m. The entire Spirit quartzite unit is anomalous with respect to gold. Given the pervasive nature of the alteration, and the close spacing of veins, there is potential for a bulk-tonnage type deposit.
Drilling should respect vein orientation. Since veins have a preferred bedding-normal orientation, the greatest density of veins will be intersected by drilling along or at a shallow oblique angle to bedding.
A similar scenario applies to the Lewis showing where the combination of consistent width of Spirit quartzite along more than 3 kilometres of strike length defines a large target.
There are five primary mineralized zones/showings on the Dewdney Trail Project: Spirit Dream, Tac, Lewis, Jack Leg and Dew Drop (see Figure 7-7 below). The two zones of greatest importance and interest as of the date of Dewdney Trail Technical Report are Spirit Dream and Lewis. These zones have the following characteristics that make them suitable as bulk tonnage targets: (i) stratigraphic continuity measured in kilometers; (ii) large, intense alteration systems featuring sericite-quart-pyrite-Fe carbonate-Fe oxide; (iii) centimeter scale spaced fractures throughout the host unit; (iv) evidence of resurgence; and (v) gold distributed throughout the host unit.
Figure 7-7: Page-scale rendering of detailed geology for the Dewdney Trail Project
Large areas with gold mineralization potential have been identified using airborne geophysical survey data on the Dewdney Trail Property. Over 20 target areas have been identified by either the airborne magnetic or conductivity signature of the rocks. (See Magnetic and Conductivity maps below) Each target area is numbered with a letter “M” for magnetic target or “C” for conductivity target area.
Spirit and Lewis showings
The Spirit and Lewis showings are large tonnage exploration opportunities characterized by:
- 1. anomalous gold values throughout the host quartzite unit;
- 2. millimeter to centimetre width, closely-spaced veins;
- 3. pervading sericite-quartz-pyrite-Fe carbonate alteration; and
- 4. episodic vein development.
The consistency of alteration and veining across a width of more than 100 m and along a strike length exceeding 4 km for both the Spirit and Lewis showings provides for significant exploration potential. The Dewdney Trail Technical Report concludes that the Spirit quartzite acted as both fluid conduit and host.
Visible gold associated with hematitic alteration is direct evidence of gold mineralization (Fig. 8-1).
The veins have a preferred orientation perpendicular to bedding, are typically a few millimetres up to a centimetre wide, centimetres to a metre in length, and spaced at centimetre to decimetre scales (Fig. 8-2).
Vein formation was recurrent, demonstrated by cross-cutting relationships (Fig. 8-3) that are consistent with the notion of a resurgent mineralizing system driven by episodic hydraulic fracture.
Figure 8-1: Visible gold (centre of photograph) in hematite filled vein cutting the Spirit quartzite host.
Figure 8-2: Typical vein morphology and spacing within Spirit quartzite. Bedding is horizontal in photograph, most veins are perpendicular to bedding. Note the close spacing (Cdn penny for scale) of veins, and vein widths from millimeter to centimetre scales.
Figure 8-3: Three stages of vein development are present: Vertical vein is latest, off-set and thinnest horizontal vein is earliest. In each case, vein reconstruction involves slight oblique movement parallel to elongate crustal growth directions.
Soil samples having anomalous gold values collected by Placer Dome Inc (1985-1990) and later confirmed by re-sampling by SG Spirit Gold in 2006 provided the impetus for trenching and sampling the southern part of the Tac showing in 2008. There, gold mineralization occurs near the contact of argillite and quartzite in brecciated quartzite, in syenite dikes and in fault gouge zones. The highest gold value (1953 g/t) was collected from a 4-5 metre wide, altered syenite dike. Typically pyrite, sericite and Fe-carbonate occur in association with anomalous gold.
The syenite dikes appear to widen and become more prevalent down slope, suggesting they may be feeding from a stock or pluton present in the valley bottom or shallowly buried beneath it. Since syenitic intrusive rocks are regarded as mineralizing agents in the area, this target merits follow-up.
Past exploration efforts included prospecting, soil geochemistry (Placer Dome survey referenced above), rock sampling, VLF-EM, magnetic surveys, IP surveys, hand trenching, and diamond drilling (Aldridge Resources program referenced below). Recent mapping of the property by SG Spirit Gold demonstrates that the focus of exploration and the location of anomalous surface rock and soil values was in the hanging wall of the Tackle Creek extension fault; however, the drill sites chosen for testing these anomalies were located on the extension fault and the drill bit tested the footwall succession without positive results.
Jack Leg Showing
Gold occurs in quartz and quartz-carbonate veins having a spatial relationship to carbonate–altered lamprophyre dikes. Significant gold values were reported by National Gold (2000-2001) across widths of 1 metre or more (AR 26662, 26905): 1955 ppb across 1 m, 302 ppb across 1 m and 604 ppb across 1.5m. A dump sample (Goldylot showing) ran 39000 ppb (39 g/t). High gold values have been reported from samples taken through the Jack Leg area; however, location and descriptive databases are incomplete and in analogue format. A small drill program undertaken by Chapleau Resources Limited (3 holes totaling 417 m) in 2003 failed to encounter gold-bearing veins (Soloviev, 2004).
Dew Drop Showing
Skarn- and intrusion-related copper-gold mineralization, are targets at the Dew Drop showing. A 1 by 3 km Cretaceous fine-crystalline to porphyritic stock of quartz monzonite, monzonite and minor syenite intrudes the Sheppard Formation (Purcell Supergroup) of mid Proterozoic age, and the Jubilee Formation, McKay Group and Beaverfoot Formation of Cambrian and Ordovician age.Skarn and fracture-related copper-gold showings are present along the intrusion margin; quartz vein and stockwork breccias hosting base- and precious-metals occur distal to the intrusion.
Soil geochemical surveys, mapping, trenching and diamond drilling have been carried out on a limited scale. None of the data was filed for assessment purposes. Dome Exploration (1984-1987) drilled 6 holes in the vicinity of one copper anomaly. Values up to 275 ppm were recorded. All holes intersected syenite, quartz diorite, skarn or hornfels.
At the Spirit and Lewis showings, alteration, expressed as a creamy buff to orange weathering color, is pervasive, observed the entire width and length of the Spirit quartzite host (Fig. 8-4). Under magnification, sericite and the oxidized remnants of disseminated pyrite are ubiquitous. Several varieties of hematite are present with the brick-red oxide (Fig. 8-5) most likely to have visible gold associated with it. Limonite is also evident in most outcrops.
Veins are typically filled with hematite and (or) limonite, quartz, and pyrite, ± Cu oxide and magnetite.
This style of alteration is well developed on the Lewis showing, located at the northern end of the western panel of Spirit quartzite. It is obvious as an orange-brown weathering ridge- top exposure and at the outcrop scale where vein morphology and alteration minerals are consistent with those seen in the eastern panel of Spirit quartzite. This area did not receive detailed examination or sampling; however, preliminary observations and results (Table VIII-I) suggest it too is a prime target for additional work.
Similar but less well developed alteration mineralogy is present at the Tac showing.
Extensive carbonate and iron alteration is present on the Jack Leg showing.
Figure 8-4: Quartz-limonite vein suggesting at least two episodes of dilation, the first associated with deposition of quartz, the second with the deposition of limonite. In this case, the vein is antitaxial because reopening occurred along the vein wall as opposed to the vein axis.
Figure 8-5: Red hematite alteration. Most visible gold is found associated with this color of hematite; hence it is a good prospecting guide.
Sediment Hosted Vein (SHV) deposits contain some of the largest gold reserves in the world. In Asia they include: Muruntau (>80M oz), SukHöy Log (>20 M oz), and Amantaytau, Daugiztau, Kumtor, Bakirchik, Olympiada, Nezhdaninskoe, Natalka and Maysky (all > 5 M oz); in Australia, deposits of the Victorian gold fields include: Bendigo (> 20 M oz), Ballarat, Fostereville and Stawell; in New Zealand: Macraes plus numerous smaller deposits; in south America there are enumerable small to medium deposits; and in North America numerous small to medium deposits occur in the Meguma terrane of Nova Scotia.
Worldwide distribution of sediment-hosted-vein type deposits (SHV deposits). *Source: Mineral Resources Services Inc.
Characteristics common to this deposit type include: tectonic setting, host rocks, alteration style, metal content, and hydrothermal fluid chemistry. SHV deposits tend to be hosted by large-extent shale and siltstone packages deposited as continental margin terrace sequences that subsequently underwent fold and thrust deformation.
Quartz and quartz-carbonate veins with gold, associated with a distinctive alteration signature, characterize SHV deposits. Carbonate alteration accompanied by sericite in a bleached host rock exhibiting pastel surface colors (mauve, kaki, yellow-brown and sand) are typical. Often, these are gold-only systems, making mineralogy and mining straightforward.
The Spirit, Tac and Lewis showings fit these criteria – especially the Spirit Showing. For example:
- the host sandstone is mid Proterozoic age;
- the host sandstone was deposited along a continental margin in a facies change between thick, deep-water clastic rocks on the west and a thin sequence of shallow water rocks on the east;
- the alteration assemblage includes sericite, quartz, pyrite, Fe-carbonate;
- pyrite was introduced to the system and occurs as euhedral cubes of varying sizes;
- gold is the only systematically enriched metal;
- spirit Showing is spatially associated with the Wild Horse Placer deposits;/li>
- there are several showings of the same type in close proximity;
- granitic rocks are spatially associated; and
- age of mineralization is likely Mesozoic and associated with several pulses of Mesozoic and Tertiary folding and thrusting.
Given the proximity of the Spirit Showing to the Wild Horse River, the author of the Technical Report postulates it was the source for the Wild Horse placer gold deposits located 8 kilometres down stream. Reasoning is based on two observations:
- 1. The quartzite is nearby and has the most consistently anomalous gold values over a significant width and strike length; and
- 2. it occupies the only large bowl-shaped catchment basin along either slope of the river from where sufficient material could have been sourced to create a sizeable placer deposit downstream.
The Dewdney Trail Property is part of a regional-scale, east-verging hanging wall anticline detached above the Lussier Thrust Fault. The structure is intruded by Late Cretaceous syenitic dikes derived from stocks that may have injected heat and mineralizing fluids into the evolving fold-thrust structure.
Of the five areas or showings where gold mineralization is known: Spirit, Tac, Lewis, Jack Leg and Dew Drop, the Spirit and Lewis showings exhibit many features in common that support potential for a large tonnage deposit of the SHV (sediment-hosted vein) type. In the author’s opinion, these two showing have significant promise and should be the focus of future exploration of the property.
Thrust faulting and associated hanging wall folding proceeded in a pulse-like fashion, controlled by cycles of fluid pressure build-up and release (valving) which has the effect of redistributing large volumes of over pressured fluids. The intense, widely distributed fractures and veins, wholesale alteration and visible gold reflect the many cycles of “valving” the host rocks underwent during deformation.
The role of dike and stock intrusions is not fully understood but is considered important in the mineralizing process: as a source of gold-bearing fluids and of heat.
As a consequence, the Dewdney Trail Property has the following attributes:
- it contains large-tonnage gold prospects;
- visible gold is hosted by quartzite (arenite and wacke) within the upper part of Mesoproterozoic Aldridge Formation (Spirit and Lewis showings);
- rock samples containing gold concentrations to 18 grams per tonne highlight a mineralized unit, the Spirit quartzite (informal), approximately 100 m thick and having a strike length in excess of 5 km;
- gold targets (Spirit, Tac, Lewis, Jack Leg) are pervasively altered (sericite-quartz-pyrite-Fe oxide-Fe carbonate) and veined.;
- veins (Spirit and Lewis) are closely spaced (centimetre scale), have widths ranging from millimeters to centimetres, and range in length from centimetres to more than a metre;
- there is a preferred vein orientation perpendicular to bedding (Spirit), an observation that should be taken into account when planning a drill program;
- multiple episodes of vein production (Spirit and Lewis) are evidence that the mineralizing system was resurgent;
- the combination: stratigraphic setting (permeable quartzite sandwiched between argillite aquatards) and structural setting (a steep, overturned, west-dipping rock panel detached above the major east-verging Lussier thrust fault) account for both the focused fluid flow and the resurgent nature of the fluid system;
- he Spirit Showing, part of which occupies a large catchment bowl located on the south-facing slope of the Wild Horse River, and from which substantial material has been removed by alpine glaciations and stream erosion, represents a likely source for theWild Horse River gold placer deposits (located 8 km downstream) from which 1.5 million ounces of gold have been recovered; and
- the Property is part of the regional Kimberley gold trend, a zone of anomalous gold concentrations which can be traced approximately 100 km from near the town of Creston, east northeast across the Purcell Mountains to the Rocky Mountain Trench at Cranbrook, and from there to the north along the Hughes Range of the western Rocky Mountains.
The Dewdney Trail Property has potential to host large tonnage Sediment-Hosted-Vein (SHV) gold deposits. An airborne geophysical survey has identified more than 20 (magnetic and/or conductive) target areas for follow-up on the property. Target areas all occur in a broad predominantly quartzite rock unit that contains anomalous gold ranging up to 18 g/t in grab samples. The quartzite unit ranges from 75m to over 200m in true width and can be traced for over 12 kilometres on the property.
Since PJX commenced trading on September 14, 2011, the Company has completed completed initial trenching and drilling programs on the large Dewdney Trail gold property near Cranbrook, British Columbia.
PJX drilled 4 holes (totaling 750 m) to test the quartzite unit at depth in one part of the M1 target area. This drilling was done to obtain a more representative sample of the unit and to help identify any structural controls that may relate to mineralization. The results of this work will be used to plan the most efficient way to evaluate the entire M1 target area and other target areas on the property. The M1 target area is approximately 800m wide by over 1km in strike length. Drilling was done on one small part of the target area that was approximately 100m by 200m.
The Company has completed more than 4.5 kilometres (km) of trail and over 500 metres (m) of trenching on 3 of the 20 target areas on the Dewdney Trail Property. Work on the M1 target area has discovered that the quartzite unit with interbedded argillite appears to be over 250m in true width. The quartzite is variably altered with sericite, iron-carbonate and iron-oxide mineralization. Multiple episodes of cross-cutting quartz veining and/or flooding are predominantly evident in the quartzite part of the unit.
While the trenching and drilling program focused on only 3 of the over 20 target areas on the Dewdney Trail property, approximately 60% of the 20 target areas have been preliminarily assessed by prospecting and mapping. More than 400 rock grab samples have been collected and submitted for assay. Analytical results of all the prospecting samples, trench samples and drill core are expected to be received over the coming months. The results will be compiled with existing geological mapping, surface sampling and geophysics to identify and prioritize targets for trenching and drilling on the Dewdney Trail property in 2012.
Dewdney Trail Map
The large Lewis Creek, Tackle Creek and M1 target areas, along with other target areas, will be the focus of further exploration on the Dewdney Trail Property in 2012
View southeast at quartzite forming the headwall of Lewis Creek. Intense sericite-quartz-pyrite-Fe-carbonate alteration imparts orange weathering color. Rock and soil samples are anomalous in gold.
Typical vein morphology and spacing within quartzite. Bedding is horizontal in photograph, most veins are perpendicular to bedding. Note the close spacing (Cdn penny for scale) of veins, and vein widths from millimeter to centimetre scales.
Exposure of quartzite along exploration trench at the south end of the eastern panel. Turbidites, decimetres to metres thick, are separated by thin, argillaceous partings.
Massive, steep (overturned) west-dipping beds of quartzite separated by cm thick cleaved argillite interbeds.