Champion
Project

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With a trailblazing attitude and innovative mindset, Plutonic is applying modern exploration methodologies to challenge entrenched dogma in an under-explored frontier region, partially concealed beneath shifting Simpson Desert sands.

Plutonic’s Champion Project (Figure 1) is hosted by Neoproterozoic Sturtian sedimentary shelf sequences, adjacent to the Georgina Basin, and occurs near the junction of multiple Proterozoic plate margins. It is located along the poorly understood south-eastern margin and termination of the Aileron Province, a piece of Palaeoproterozoic crust in the Arunta Inlier that forms part of the North Australian Craton (Figure 2). The area preserves a record of protracted tectono-thermal activity spanning the Paleoproterozoic to Mesozoic.

Plutonic first recognised the potential of the Champion Project by considering large-scale geodynamics and the relationship between Paleozoic Central Australian orogenesis and the processes that led to enhanced gold endowment in parts of Eastern Australia. The Paleozoic Alice Springs Orogeny, well developed in the Northern Territory, was noted as being coeval with, and probably dynamically-related to, the highly-endowed Tabberabberan to Benambran Orogenies in Victoria and New South Wales.

This novel idea occurred in the context of evolving mineral-system models for gold mineralisation which see a diverse array of gold-hosting environments linked by a small number of key underlying processes. An important part of this new perspective is that although most gold mineralisation occurs at actively-deforming continental margins, it can also occur locally along major trans-lithospheric structures that may penetrate a long way into the adjacent continent. This is exactly the interpreted Paleozoic setting of the Champion project, which sits along the major, long-recognised and long-lived, continental-scale G3 Structural Corridor (Figure 3).

Major structural corridors such as these are known to host multiple mineral deposits with a variety of geological ages and commodity types, attesting to their long-lived nature and metallogenic importance. Notably, the G3 Corridor hosts the Paleoproterozoic-aged Tanami Gold Province, with a > 20 Moz endowment.

The Champion project is located in a highly favourable structural setting, adjacent to several major fault zones (Figure 4):

  • Bisecting the Arunta Inlier, the G3 Structural Corridor broadly corresponds to the WNW-WSE-striking Willowra Suture or Trans Tanami-Arunta Fault (Alston, 2000), which can be traced in magnetic and gravity data from the Granites-Tanami gold province to Champion and beyond.
  • The NE-SW-striking Cork Fault Zone separates the Arunta Inlier to the north from the Diamantina River Domain of the Thomson Orogen to the south.
  • The NW-SE-striking Toomba Fault, a high angle, SW-dipping reverse fault that has been active from the Palaeoproterozoic to the Cretaceous.


This geodynamic setting is considered ideal for the formation of giant mineral systems, especially within the context of a potential Palaeozoic convergent plate boundary and a major structure capable of channelling intrusions and fluids that are crucial to the formation of mineral systems.

Regional scale quartz veins, vein arrays and breccias, along with associated alteration minerals are primary exploration targets for Plutonic. Extensive quartz veins and breccias that clearly cross-cut (and hence post-date), Neoproterozoic sequences are interpreted to be related to a protracted period of orogenesis and extension during the Alice Springs Orogeny (c.a. 450-300 Ma), broadly contemporaneous with the major orogenic and extensional events and emplacement of mineralisation within the Tasmanides to the east. Age dating of sericite (40Ar/39Ar method) conducted by specialists from Curtin University on behalf of Plutonic provides a maximum age of ~450-400 Ma for an associated alteration event, adding further weight to Plutonic’s interpretation.

Age dating of carbonatites located ~100-200km SE of Champion returned age dates of ~375-380Ma.  Plutonic have discovered and sampled igneous rocks from Champion that have been submitted for radiometric age dating, results of which are expected within 6 months.

Champion’s favourable geodynamic setting, combined with compelling evidence for large-scale mineralising processes gives the area outstanding potential for district scale discoveries. Plutonic is pursuing an aggressive exploration strategy in the hunt for giant and super-giant deposits.

  • HyVista Corporation was commissioned by Plutonic to conduct an airborne hyperspectral survey covering c.a. 1,800 km2, collecting close-spaced, high resolution (1.7m pixel size) hyperspectral data. This was completed in 2023 (Figure 5). Hyperspectral instruments measure the light reflected from the earth’s surface, enabling accurate identification of materials by their unique spectral signature at very high spatial resolution.  This makes the data ideally suited to mapping the distribution of alteration systems that are commonly associated with mineralisation.
  • Over 860 rock chip samples have been collected from across the project area, most of which have been geochemically analysed. Selected surface geochemical ‘highlights’ are shown on Figure 5.
  • Completion of a 129 sample ultra-fine fraction (UFF) orientation soil sampling program (Figure 6) over the Saraya prospect and surrounding area (Figure 7).
  • Field studies have catalogued blade replacement textures, chalcedonic quartz and other vein textures (Figure 8) that indicate many of the exposed quartz veins are likely to be above the “boiling zone” where economic gold, if present, is expected to precipitate. This hints at the potential for complete preservation of epithermal ore systems below the surface.
  • Rock chip samples collected by Plutonic have returned anomalous levels of gold, silver, bismuth and copper; a significant combination due to the common association of these metals with felsic to intermediate composition magmatic-hydrothermal related ore systems.  Rock chip assay highlights include gold to 1.3 g/t, silver to 21 ppm, bismuth to 0.32% and copper to 1,840 ppm, confirming the prospectivity of the region for these key metals of interest (Figure 5). 
  • Geochronological studies were used to date intrusive samples and to determine a maximum age of ~450-400 Ma for a key phase of alteration. In situ Rb-Sr dating is currently being conducted on these samples to further constrain the age of this important regional alteration event.
  • Completed 2D and 3D geochemical modelling of rock chip assays have provided vectors towards areas of interest, based on elemental abundances and trends in diagnostic elemental ratios. Results strongly support the porphyry-epithermal system model (Figure 9).
  • Innovative Fuzzy Logic modelling for porphyry and low sulphidation epithermal mineral systems confirmed the interpreted prospectivity of key prospects and assisted with the identification of others (Figure 10).
  • Cataloguing and assessment of rock samples and geochemical data by epithermal, porphyry and structural targeting experts.

The hyperspectral survey data contain indications of alteration mineral assemblages that are characteristic of both high sulphidation epithermal systems and geologically related (deeper) porphyry systems. The potential for both, geologically related systems to be preserved in the area is further supported by field observations and geochemical modelling. The processed hyperspectral data are a powerful tool for the assessment of known exploration targets and for providing indications of new targets in areas that have not previously been visited by geologists.

Hyperspectral data are supported by on-ground observations including diagnostic quartz textures (Figure 8), arrays of quartz veining, hydrothermal breccias (Figure 11), sulphide mineralisation and observed silicic and advanced argillic alteration (Figure 12). Rock chip geochemistry for metals and pathfinder elements is highly encouraging and supportive of the interpreted mineral system model. All of these features are consistent with the outflow zones of significant porphyry/epithermal mineral systems that may be preserved at depth and near the surface.

Work completed up until now has quickly advanced Plutonic’s understanding of the Champion project, and the geological model has evolved as a consequence. Plutonic has developed its exploration model based on patterns of alteration, veining and other observable features that are characteristic of well understood mineralisation systems that contain significant quantities of ore minerals. The observed similarities are extremely encouraging, especially considering the number of targets and scale of the mineral system under consideration at Champion.

Low sulphidation epithermal systems and high sulphidation epithermal systems contribute a significant proportion of global gold reserves and production, and porphyry systems are the geological style that constitutes the largest proportion of world copper reserves.

Plutonic has identified the potential for gold or copper mineral systems in a range of genetically-related settings at Champion:

  • Low sulphidation epithermal gold (+/- silver).  Observed quartz textures in outcropping veins strongly suggest that the upper levels of the systems are intact and the prospective “boiling zone”, where gold is typically concentrated, is likely preserved at depth.
  • High Sulphidation epithermal gold (+/- copper, silver).   Multiple zones of steam-heated alteration of the country rock is evidenced by field observations (Figure 12) and advanced argillic alteration minerals mapped in the hyperspectral data.
  • Porphyry copper-gold.  The presence of widespread porphyry veining (distal stockwork) and alteration systems including propylitic, advanced argillic and potentially phyllic are observed in both field samples and hyperspectral data. If the porphyry roots of the advanced argillic alteration zones are mineralised, they are likely to be preserved at depth and/or lateral to these zones. Copper and gold mineralisation, if present, is usually associated with the early stage potassic core of the system.

Detailed interpretation of the hyperspectral data in combination with recent and historic geochemical sampling and structural interpretation has led to the delineation of several stand-out areas of interest (Figure 13).

McLovin’

  • Six-kilometre quartz vein corridor (Figure 14) hosting numerous large veins with abundant blade replacement quartz textures signifying the top of a large potential low sulphidation epithermal system (above the boiling zone where gold is typically enriched), with some overprinting alteration possibly linked to a later porphyry event
  • Numerous large hydrothermal breccia zones, broad stockwork veining and large discrete vein corridors
  • Highly anomalous geochemical footprint yielding bismuth up to >0.3%, anomalous gold to 0.17g/t, and copper to 654 ppm in rock chip samples
     

Icarus

  • Large (Figure 15) 26km x 10km zone of Epidote + Chlorite + Carbonate (Propylitic alteration) and Sericitic-phengite/silicic alteration (possible phyllic alteration)
  • Pervasive phlogopite (Mg-rich biotite, potentially system core proximal)
  • Magnetic low corridor (interpreted very large alteration system) enveloped within adjacent magnetic high corridors and proximal advanced argillic alteration (pyrophyllite-dickite-kaolinite) at the Apotheosis and I Am the One prospects
  • Located at the junction between N-S and NW-trending regional-scale structures
  • The combined structural setting and broad scale alteration pattern are analogous with porphyry style intrusive target

Apotheosis

  • Extensive >5km pyrophyllite-dickite-kaolinite footprint (intense advanced argillic alteration) within the broader Icarus alteration zone (Figure 15), hosted by Neoproterozoic tillite/diamictite/conglomerate 
  • Discrete target of concentrically zoned alteration with an inner hypogene pyrophyllite-dominant core (Figure 16)
  • Kaolin is highly ordered (i.e., crystalline and related to alteration, not weathering)
  • These features are consistent with a high sulphidation epithermal gold system, which is a style of deposit which are known to be linked to porphyry systems

I Am the One

  • Extensive >9km x >1km intense advanced argillic alteration footprint (Figure 17). Similar to Apotheosis with a hypogene pyrophyllite dominant core.  Alteration is less intense at the margins, but a lot more extensive in size than Apotheosis
  • Extensive hydrothermal breccias and quartz stockwork veining
  • The alteration footprint terminates at a zone of silica that covers an area of approximately 3.5km x 2km, which is interpreted as a potential silica cap.  This silica cap was identified early in Plutonic’s prospecting efforts at Champion, and formed the basis for the original target area Saraya, which is substantially expanded now
  • Elevated levels of Cu, Mo, As, Te and high levels of Se are consistent with high temperature epithermal systems, similar to the Loki prospect to the southeast

Loki

  • Loki contains the target area previously referred to as the Keyser Group, but the identified extent of alteration and anomalous geochemistry has significantly expanded the footprint (Figure 14), and encircled other target areas within a common, enlarged area of interest
  • Very large footprint of ~5km x 6km, containing extensive residual quartz, acid leached capping, stockwork veining, hydrothermal breccias and advanced argillic alteration (Figure 12)
  • Some veins carry anomalous gold (including the highest grade gold assay returned so far: 1.3g/t Au), silver, copper, arsenic and molybdenum and zinc 
  • The observed alteration pattern, quartz veining and gold anomalism are interpreted as a high sulphidation epithermal gold target.  Additionally, the presence of elevated base metals leads Plutonic to consider that Loki may be an area that there is potential for a proximal associated porphyry target

Greater I’m Not a Vampire

  • I‘m Not a Vampire (Figure 18) is one of the original key areas of interest at Champion.  It features large scale outcropping quartz veins that are visible in Google Earth, which are amongst the features that originally attracted Plutonic to the area
  • Main vein exposure outcrops over a 5.2km section with exposures of quartz vein up to 30m wide.  This is within a structure that is interpreted to be over 60km in length, where quartz veins of similar appearance and orientation have been mapped.
  • The quartz veins (Figure 19) feature significant chalcedonic quartz, crustiform-colloform banding, multigenerational hydrothermal breccias, blade and replacement textures, minor sulphides in cut samples and more widespread interpreted ex-sulphides. 
  • Elevated gold-silver-bismuth-tellurium-selenium geochemistry
  • The main outcrop is interpreted as the upper expression of a large low sulphidation epithermal system that may have been later overprinted by a deeper porphyry system based on the presence of geochemistry and specular hematite (higher temperature fluids) in some outcrops
  • The work conducted during 2023 has identified new targets to the east and west of the main I’m Not a Vampire outcrop. These targets are proximal to the main prospect but are comparatively small patches of outcrop surrounded by sand dune cover, so geological unification is so far only interpreted on the basis of proximity.  These new target areas feature sulphides in low sulphidation vein samples and both epithermal and possible porphyry hyperspectral alteration signatures. Samples have elevated metals including up to  returned up to 4ppm bismuth, 339ppm copper, 8.8ppm molybdenum, 16.8ppm selenium, 0.8ppm tellurium and 184ppm zinc.
  • A large exposure of geyserite at the Knobby Geyser prospect could indicate large scale hydrothermal processes in the area.

Camp Lake Bottom

  • A large ~6km x 3km area of multiple advanced argillic alteration zones (Figure 14)  associated with the bases and tops of elevated topography; strong and pervasive alteration throughout, extensive veining and fracturing
  • The Camp Lake Bottom prospect area features the strongest K/Th ratio in radiometric data in the project area
  • Rock chip geochemistry demonstrates mildly elevated tellurium, tungsten, and tin 
  • The combined features of Camp Lake Bottom highlight potential for near surface high sulphidation epithermal and deeper porphyry gold-copper mineralisation at depth.

The key areas of interest described above are the areas Plutonic expects to focus on through the 2024 season, as they have the strongest combined target credentials.  They are not the only areas of interest identified, and a brief summary of other target areas is presented in Table 1

 

TARGETDESCRIPTION
SarayaLarge >3.4km silica cap/barren lithocap with porphyry hyperspectral and geochemical footprint. Flanked by low sulphidation epithermal veins.
ValhallaVery large >9km silica cap/barren lithocaps with extensive porphyry hyperspectral and sporadic geochemical footprint. Cross-cutting multi-km vein corridors.
Chupapi Munyanyo~27km x 7km corridor of low sulphidation veining, suspected recrystallised sinter material and both epithermal and porphyry hyperspectral signatures; stockwork and sheeted veining;
Asgard NorthVery large low sulphidation style epithermal veins, in some areas overprinted by later suspected porphyry alteration; Presence of specular hematite veining signifies warmer hydrothermal fluids associated with a proximal intrusive/porphyry system. Elevated copper and presence of fluorite support the proximity to intrusive
Shaft of Destiny6km vein system with strong coincident epithermal hyperspectral signature terminating at the NNE end into the McLovin’ target zone
RonnieVery large silica cap/barren lithocaps with zones of interpreted intense acid leaching and associated quartz veins; extensive porphyry favourability in hyperspectral data
PorpheticIntense epithermal hyperspectral response along the NW trending Toomba Range, flanked to the west by porphyry hyperspectral responses in Cambrian-Cambro-ordovician carbonate sequences. Some evidence for skarnification of carbonates.

Table 1. Additional important target areas at Champion.

The addition of new target styles to the Champion exploration model, and identification of key areas of interest positions Champion for a more focused work program in 2024, intended to take several of the high priority targets to “drill ready” status.

The proposed work program includes:

  • Geochemistry – analysis and expansion of the well-established rock chip database, to provide vectoring to areas of potential economic interest via metal abundance, alteration intensity and key pathfinder element and ratio analysis
  • Geophysics – Induced Polarisation (IP) geophysics measure chargeability and resistivity responses, which can provide proxies for sub-surface sulphide accumulation or quartz vein development or alteration. A very large survey to screen our targets is due to commence around late April 2024.
  • Field mapping, reconnaissance, texture cataloguing and ground truthing.

Plutonic looks forward to an exciting year of discovery work and relishes the opportunity to be pioneers in this highly prospective new district.

Project Gallery

Chasing Hypergiants

Figure 19

I’m Not a Vampire quartz vein – south-western side, view looking NW.

Figure 18

HyMap Hyperspectral imagery – Sericite/Mica/Illite Crystallinity in the Greater I’m Not a Vampire and area. Water content within illites and white micas can be measured by the ratio of H20 versus Al-OH absorption near 1950 nm and 2200 nm respectively – termed illite crystallinity (IX). Warmer colours (red/orange/yellow) generally indicate a higher temperature of sericite/mica crystallisation. Cooler colours (blues) commonly reflect areas of poorly crystalline micas (illites) characterised by high water and low Al-OH content.

Figure 17

HyMap Hyperspectral imagery – Advanced argillic alteration (ternary Pyrophyllite – Dickite – Kaolin) over the I Am the One prospect. Also shown are the locations of rock chip samples collected by Plutonic. The background image is a false colour composite (HyMap bands 16, 8 and 3 – equivalent to true colour air photo).

Figure 16

HyMap Hyperspectral imagery – Advanced argillic alteration (ternary Pyrophyllite – Dickite – Kaolin) over the Apotheosis prospect. Also shown are the locations of rock chip samples collected by Plutonic. The background image is a false colour composite (HyMap bands 16, 8 and 3 – equivalent to true colour air photo).

Figure 15

(a) Porphyry and (b) Epithermal Gold Fuzzy Logic favourability maps covering the Icarus prospect and surrounding areas (the field of view is the same in both images). Prospectivity models were constructed by combining several different spatial data ‘layers’, with each model input being carefully selected to represent a critical component of the mineral system. The resulting maps are a useful first-pass indicator of relative prospectivity and a powerful targeting tool.

Figure 14

HyMap Hyperspectral imagery – Advanced argillic alteration (ternary Pyrophyllite – Dickite – Kaolin) over the Camp Lake Bottom, McLovin and Loki prospects. Also shown are the locations of rock chip samples collected by Plutonic. The background image is a false colour composite (HyMap bands 16, 8 and 3 – equivalent to true colour air photo).

Figure 13

High-priority target areas at Plutonic’s Champion Project.

Figure 12

Typical advanced argillic outcrop from the Loki target area. Rock chips local to this outcrop returned elevated copper (to 396ppm), tellurium (to 0.93ppm), selenium (to 3.2ppm), molybdenum (to 3.1 ppm), germanium (to 2.75 ppm) and zinc (to 1240ppm).

Figure 11

Examples of breccias from Champion. (a) I’m Not a Vampire reef – Epizonal quartz outcrop – multi-veined breccia with strong crustiform banding and some comb quartz, (b) Angular quartz clasts in a matrix dominated by specular haematite – I’m Not a Vampire reef, (c) Quartz-haematite breccia – Asgard Dome North, (d) Sample Dam002, McLovin’ Prospect – Hydrothermal breccia with cockade textures, quartz matrix dominant, (e) I’m Not a Vampire reef –  cut hand specimen of multi-phase Infill breccia with cockade/colloform textures, fine chalcedonic banding, dark quartz, ex-sulphides.

Figure 10

Fuzzy Logic prospectivity modelling attempts to digitally combine large amounts of spatial data using sound logic and reasoning. It is an entirely knowledge-driven approach to computer-aided favourability mapping. The models are designed to reflect the geoscientists’ thoughts and ideas. Two distinct models have been prepared for the Champion Project; the results display relative favourability for (a) Low sulphidation epithermal mineral systems, and (b) Porphyry/high sulphidation mineral systems.

Figure 9

3D geochemical modelling of rock chip assays provide vectors towards areas of interest based on elemental abundances and trends in diagnostic elemental ratios. Also shown is Plutonic’s 3D inversion of magnetic data (interpreted as potential intrusive corridors) and a preliminary structural interpretation. 3D view looking NW.

Figure 8

Examples of geochemically anomalous rock samples and epithermal/hydrothermal quartz textures from the Champion Project.

Figure 7

View looking southwest, across plains covered by recent sedimentary cover and towards the mesas and outcropping quartz veins of the Saraya prospect. This area was selected for a trial Ultra Fine Fraction (UFF)  soil survey.

Figure 6

Examples of gridded Ultra Fine Fraction (UFF) orientation soil survey results (a) Gold – Au, (b) Silver – Ag and (c) Mercury – Hg.

Figure 5

HyMap Al-OH wavelength shift map. Spatial variation in the wavelength of a diagnostic electromagnetic absorption feature is a result of element substitution within the crystal lattice, reflecting the chemical conditions at the time of crystallisation. Warmer colours (red/orange) in the Al-OH wavelength shift map generally indicate more alkaline conditions. Cooler colours (blue/green) indicate higher Al content and more acidic conditions. Surface geochemical ‘highlights’ are also shown.

Figure 4

Structural setting of the Champion Project. Source: Geoscience Australia 1: 1 million-scale structure and regional interpretation by Plutonic Limited over Geoscience Australia Variable Reduction to Pole (VRTP) Magnetics V6, 2015.

Figure 3

Continental Scale architecture showing the distribution of Paleozoic rifts in close proximity to the G3 structural corridor, the “Tasman Line” separating stable Paleozoic continental rocks to the west from the accretionary orogen to the east and significant gold occurrences associated with these structural zones. Paleozoic rifts are commonly concealed by younger (post-Paleozoic) sedimentary basin sequences. The Champion Project area is interpreted as a rare exception.

Figure 2

Precambrian and early Palaeozoic provinces of the North Australian Craton. The Aileron Province, part of the Arunta Inlier is indicated by the black hashed area.

Figure 1

Plutonic’s Champion Project location map. Granted tenements are shown in dark grey, applications are shown in light grey.