Tritton

Greenfields and Brownfields Exploration at the Tritton Copper Operations (NSW)

Greenfields and Brownfields Exploration at the Tritton Copper Operations (NSW).  The Tritton tenement package in New South Wales comprises seven exploration and mining licences covering 2,160km2 of highly prospective ground for base metal deposits within the Girilambone Basin. Since modern exploration commenced in the 1980s, more than 750,000 tonnes of copper, has been discovered within the 100% Aeris-owned Tritton tenement package. Geological mapping has extended the known extents of the Budgery Sandstone unit a further 65 kilometres through the northern half of the tenement package, with the potential to extend a further 40 kilometres.

The nearby Canbelego Project (Aeris 30%) is held through a Joint Venture with Helix Resources.

Aeris’ exploration strategy within the Tritton tenement package is based on growing the operations through the extension of mineralisation at the current Mineral Resource deposits, principally at Tritton and Murrawombie, and focussing on the potential discovery of new copper sulphide deposits.

Recent greenfields exploration has been focused on the under-explored northern half of the tenement package above and east from Avoca Tank. The principal form of exploration was via the utilisation of airborne and ground-based electromagnetic (EM) survey techniques.

The EM technology is designed to detect for massive sulphide deposits to 500 metres (ground) and 300 metres (airborne) below surface. Advancements in the genetic understanding of the mineralised system have continued to focus on structural and mineralogical relationships. Copper sulphide mineralisation is considered to occur along late stage structural fabrics in regions containing secondary magnetite.

Exploration activities in FY2020 included:

  • Underground drilling at the Murrawombie deposit further extended the limits of the known mineralized envelopes, with variable quantities of sulphides intersected, culminating in the identification of three new copper sulphide lodes;
  • Completion of ground-based electromagnetic (MLTEM) surveying over each priority airborne EM anomaly within the northern half of the tenement package. Constellation deposit (previously known as Anomaly K) was confirmed as bedrock conductor;
  • Completion of MLTEM surveying between the Murrawombie and Avoca Tank prospective corridor;
  • Completion of a modest drill campaign, totalling three drill holes within the Murrawombie to Avoca Tank prospective corridor – which confirmed downplunge extension of mineralisation at the Caribou Prospect; and
  • Exploration licence (EL) EL8987 was granted and covers a potential extension of Constellation deposit off the current Tritton tenement package.

 

Regional Geology Compilation

Exploration work across the Tritton tenement package has historically been focused around the current Mineral Resource deposits. The amount of greenfield exploration further afield was historically focused, primarily along the Budgery Sandstone stratigraphic corridor between the Budgery and Avoca Tank deposits and along the Kurrajong – Birrimba magnetic complex. From 2018 onwards, there has been renewed interest in the northern half of the tenement package with the understanding that the prospective Budgery-Sandstone unit extends throughout the field, with regional mapping confirming an additional 65 kilometres and the potential for a further 40 kilometres within EL8810.

Known mineralisation discovered within the Tritton tenement package to date located proximal to the Budgery-Sandstone unit is approximately 750,000 tonnes of copper metal along a 50 kilometre section of the Budgery-Sandstone corridor.

To date, the majority of the on-ground exploration within the Tritton tenement package has been focussed within the southern half, along the prospective “Budgery Sandstone” corridor between the Budgery and Avoca Tank deposits.

Exploration of the northern part of the tenement package has been limited until the recently completed airborne EM surveys, with previous exploration limited to one airborne EM survey flown in the late 1990s. A recent review of the historical EM survey data from the late 1990s indicated it was largely ineffective in detecting concealed mineralisation below surface.

Recent regional mapping and follow-up geophysical interpretation over the northern half of the tenement package was successful in identifying the continuation of the Budgery Sandstone unit for a further 65 kilometres than originally thought. Additionally, the prospective corridor was interpreted to extend a further 40 kilometres further northwest, into an area now covered by EL 8810.

EL8810 was granted in late 2018 and is located adjacent to the north-west corner of the current Tritton tenement package. The new tenement, covering an area of  296km2, brings the total Tritton tenement package to 2,160km2, covering the known 155-kilometre strike extent of the Budgery Sandstone unit.

An initial trial airborne EM (AEM) survey was flown over selected areas of the Tritton tenement package in January 2018 to determine the effectiveness of this method in the detection of potential bedrock conductors. The survey was successful in identifying 4 new potential bedrock conductors along the northern margin of the tenement package.

A second AEM survey covering the remainder of the under-explored northern half of the tenement package (617km2– excluding EL8810) was flown in January 2019 and identified a further 25 EM anomalies, including 9 high-priority targets. The airborne EM survey was flown using the SKYTEMTM 312 EM system, which is designed and optimised for deep conductor bodies. This system enabled exploration to quickly and cost-effectively identify potential copper sulphide mineralisation.

A ground based moving loop electromagnetic (MLTEM) surveying was completed over the AEM conductive bodies.  The MLTEM survey was designed to filter out the AEM anomalies which are legitimate bedrock conductors from those which are related to noise or near surface cover responses.  One anomaly (Anomaly K) has been confirmed as a legitimate bedrock conductor

A separate ground MLTEM survey was completed within the highly prospective Murrawombie to Avoca corridor. In total, seven copper sulphide bodies have been discovered within the 7.5 kilometre strike corridor to date. A modest drill campaign was completed within the corridor after the completion of the MLTEM survey. A drillhole at the Caribou prospect intersected low grade copper mineralisation downplunge and also detected an off-hole EM conductor (Murrawombie North). Both warrant additional work.

Aeris will focus it’s exploration efforts at Tritton on the most prospective areas throughout the tenement package in FY2021. Regional surface geochemical sampling programs will be completed over high priority regions which may host either massive sulphide deposits analogous to the style of mineralisation which characterises Tritton and Murrawombie and non-conductive mineralisation styles analogous to the north-east deposit.

Constellation deposit 

The Constellation deposit is located approximately 45 kilometres north east from the Tritton Operation in central western New South Wales. The deposit was first detected via an airborne electromagnetic survey with follow-up ground moving loop (MLTEM) surveying completed in the previous quarter. The MLTEM survey verified the EM response represented a legitimate bedrock conductor. Two bedrock conductors were identified.

The Constellation deposit is defined by two modelled EM conductors based off a moving loop electromagnetic (MLTEM) survey.  The larger EM plate is approximately 250 metres (strike) x 250 metres (dip) and located from 150 metres below surface.  Approximately 300 metres to the west is a smaller modelled EM plate with dimensions in range of 30 metres (strike) x 100 metres (dip).

Diamond Drill Summary

Drilling at the Constellation deposit has focused on drill testing the larger moving loop electromagnetic (MLTEM) plate.  Of the 24 drill holes completed to date, 22 have targeted the larger primary copper sulphide MLTEM plate, whilst the remaining drill hole (TAKD002) intersected a shallower supergene copper system approximately 300 metres to the west.

Apart from drill hole TAKD004, each drill hole assayed to date on the larger MLTEM plate has reported high grade copper intervals, irrespective of whether they intersected the core or known margins of the mineralised system. High grade copper assay results reported from within the larger MLTEM plate include:

  • TAKD001 19.95m @ 2.41% Cu, 0.64g/t Au, 4.6g/t Ag;
  • TAKD003 27.10m @ 1.61% Cu, 0.43g/t Au, 3.4g/t Ag;
  • TAKD005 2.60m @ 6.10% Cu, 0.99g/t Au, 11.0g/t Ag;
  • TAKD006 5.85m @ 4.60% Cu, 0.96g/t Au, 8.4 g/t Ag;
  • TAKD007 24.6m @ 1.45% Cu, 0.49g/t Au, 3.0g/t Ag;
  • TAKD009 0.7m @ 2.58% Cu, 0.61g/t Au, 6.9g/t Ag;
  • TAKD010 7.0m @ 1.43% Cu, 1.77g/t Au, 2.4g/t Ag; and
  • TAKD011 1.75m @ 8.54% Cu, 5.62g/t Au, 21.9g/t Ag.

Based on the diamond drilling program completed to date the mineralised system has been traced 850m down plunge and 200m along strike.  Mineralisation remains open along strike (south) and down plunge.

The key drivers of the size of mineral deposits within the Tritton tenement package is the strike and down plunge lengths.  The Tritton deposit, which is between 25 to 30Mt, is the largest deposit and has a maximum strike length of 300m and a down plunge length of approximately 2km (still open).  The next largest deposit, Murrawombie, is between 10 to 15Mt in size.  Mineralisation at Murrawombie is defined within multiple stacked sulphide bodies with a maximum strike length of 300m and a down plunge length of approximately 1km (still open).

In comparison, from drilling data to date, Constellation has been traced to date 200m along strike and 850m down plunge.  Recently completed DHEM surveying has identified two large (75m x 350m) moderate to strong conductance (1,500S to 2,000S) EM plates which extend approximately 300m further down plunge.  Including the modelled EM plates, the mineralised system is continuous 1,150m down plunge.  Importantly mineralisation remains open along strike (south) and down plunge.

Drill hole TAKD002 targeted a smaller conductive plate approximately 300 metres further west.  The drill hole intersected a chalcocite dominant supergene copper interval (3.55m @ 22.56% Cu).  Further drilling is required to understand how the shallow supergene mineralisation relates to the deeper primary copper mineralisation.  Approval has been received for 60 RC drill holes and these will be focused on the EM plates around TAKD002.

Plan view showing location of drill holes completed at the Constellation deposit and the interpreted extents of the mineralised system.

Cross section through the Constellation deposit showing completed drill holes and significant assay results through the oxide and supergene copper horizons. The modelled lenses are interpretative and subject to change with additional drilling along the section.

A summary of drill holes completed at the Constellation deposit are included below:

Drill Hole Result
TAKD001 19.95m @ 2.41% Cu, 0.64g/t Au and 4.6g/t Ag
TAKD002 3.55m @22.56% Cu, 2.57g/t Au and 16.1g/t Ag
TAKD003 27.1m @ 1.61% Cu, 0.43g/t Au and 3.4g/t Ag
TAKD004 Failed to intersect copper sulphide horizon on northern perimeter
TAKD005 2.6m @6.10% Cu, 0.99g/t Au and 11.0g/t Ag
TAKD006 5.85m @ 4.60% Cu, 0.96g/t Au and 28.6g/t Ag
TAKD007 24.6m @ 1.45% Cu, 0.49g/t Au, 3.0g/t Ag
TAKD008 Hole abandoned due to drill deviating too far from target
TAKD009 0.70m @ 2.58% Cu, 0.61g/t Au, 6.9g/t Ag
TAKD010 25.0m @ 0.66% Cu, 0.71g/t Au, 1.1g/t Ag from 211m including 7.0m @ 1.43% Cu, 1.77g/t Au, 2.4g/t Ag from 221m
TAKD011 1.75m @ 8.54% Cu, 5.62g/t Au, 21.9g/t Ag
TAKD012 TAKD012 intersected an approx.10 metre thick (true thickness) sulphide interval (assays pending)
TAKD013 Failed to intersect copper sulphide horizon on northern perimeter
TAKD014 TAKD014 intersected an approximate 19 metre thick (true thickness) sulphide interval (assays pending)
TAKD015 TAKD015 intersected an approx. 18m thick sulphide interval (assays pending)
TAKD016 TAKD016 intersected an approx. 8m thick sulphide interval (assays pending)
TAKD017 TAKD017 intersected an approx. 20m thick sulphide interval (assays pending)
TAKD018 TAKD018 intersected an approx.16m thick sulphide interval (assays pending).
TAKD019 TAKD019 intersected an approx.60m thick sulphide interval (assays pending)
TAKD020 TAKD020 intersected an approx. 1m thick sulphide interval
TAKD021 TAKD021 intersected an approx. 13m thick sulphide interval
TAKD022 TAKD022 intersected an approx. 20m thick sulphide interval
TAKD023 TAKD023 intersected an approx. 20m thick sulphide interval
TAKD024 TAKD024 intersected an approx. 22m thick sulphide interval

RC Drill Program

RC drilling at the Constellation deposit is focused on defining the lateral extents of shallow oxide/supergene enriched copper mineralisation intersected in diamond drill hole TAKD002 (3.55m @ 22.56% Cu) and two modeled EM plates via ground MLTEM and DHEM surveys.

An RC drill program is underway at the Constellation deposit and is designed to test the extents of shallow oxide and supergene copper mineralisation first identified from diamond drill hole TAKD002.  The RC drill program has now defined the oxide and supergene copper footprint approximately 150m along strike and 130m down plunge.  Mineralisation remains open to the south.

52 RC drill holes have been completed to date, with assays received for 22 and assays pending on the remaining 30.  Two applications to the NSW Resources Regulator have been submitted for an additional 40 RC holes in the adjoining two exploration tenements.  The application to complete 19 RC holes in EL8084 has been approved.

Between 10 to 15 RC drill holes intersected water at or within the mineralised horizon and were stopped.  Work is currently underway to extend each hole via diamond drilling and once this work is completed the RC drill program will continue on new holes.

Significant high grade copper intersections returned from the assay results include:

  • TAKRC024 – 38m @ 3.72% Cu, 0.36g/t Au, 3.1g/t Ag (from 8m)
  • TAKRC025 – 47m @ 3.90% Cu, 0.96g/t Au, 5.6g/t Ag (from 11m)
  • TAKRC004 – 38m @ 2.91% Cu, 0.47g/t Au, 1.8g/t Ag (from 44m)
  • TAKRC003 – 10m @ 5.48% Cu, 0.83g/t Au, 3.7g/t Ag (from 40m) including:
    • 5m @ 10.77% Cu, 1.56g/t Au, 6.8g/t Ag (from 45m)
  • TAKRC010 – 42m @ 1.56% Cu, 0.92g/t Au, 1.7g/t Ag (from 31m) including
    • 14m @ 2.37% Cu, 1.18g/t Au, 0.9g/t Ag (from 41m)
    • 10m @ 2.65% Cu, 1.28g/t Au, 4.6g/t Ag (from 62m)
  • TAKRC006 – 30m @ 1.47% Cu, 0.47g/t Au, 2.9g/t Ag (from 92m) including
    • 8m @ 2.58% Cu, 0.53g/t Au, 5.4g/t Ag (from 103m)
    • 6m @ 3.02% Cu, 1.31g/t Au, 4.7g/t Ag (from 116m)
  • TAKRC006 -12m @ 2.58% Cu, 1.41g/t Au, 3.6g/t Ag (from 127m)
  • TAKRC009 – 13m @ 2.15% Cu, 0.27g/t Au, 4.5g/t Ag (from 94m)
  • TAKRC022 – 4m @ 4.26% Cu, 1.05g/t Au, 9.3g/t Ag (from 122m)

RC drilling assay results received to date are from a majority of the initial 40m x 40m spaced drill holes.  The reported copper intersections are thicker than expected, when compared to the initial visual estimates of copper minerals recorded from the RC chips.  Surrounding most of the logged chalcocite lenses are broader zones of disseminated sulphides also containing copper minerals.  The proportion of copper minerals within the disseminated sulphides are greater than initial visual estimates and account for the increased reportable thicknesses.

A copper oxide horizon, forming sub-horizontal “blankets” from 5m to 40m below surface, has shown to be associated with lower grade copper mineralisation. Copper assays within this oxide horizon are generally less than 1%, with localized zones of higher grade copper, as reported in drill holes TAKRC024 and TAKRC025.

Higher grade copper mineralisation is primarily associated with the supergene copper horizon beneath the oxide horizon(s).  The main copper mineral within the supergene zone, chalcocite, has been traced approximately 150m along strike and down to 130m below surface.  The supergene horizon seems to be best developed along the mineralised structure, dipping moderately southeast and trending northeast-southwest.

Native copper has been observed in some RC holes.  The assay results reported do not discriminate between oxide, supergene, native copper or primary copper minerals.  Samples through the mineralised zones will undergo more sophisticated analytical techniques to quantify the proportion of oxide, supergene, primary and native copper within.

Plan view showing location of drill holes completed at the shallower end of the Constellation deposit.
Cross section through the Constellation deposit showing completed drill holes and significant assay results through the oxide and supergene copper horizons. The modelled lenses are interpretative and subject to change with additional drilling along the section.

Tritton – Budgerygar Corridor

Tritton Deposit 

The Tritton – Budgerygar corridor is a highly prospective copper rich mineralised system. In the context of base metal deposits within the Girilambone basin, the Tritton deposit represents a very large mineralised system. The copper sulphide mineralised footprint has been traced over 1.9 kilometres down plunge based on current drilling data, and the deposit remains open down plunge.

The level of geological understanding of the Tritton deposit has increased significantly during the year as the underground development exposes more of the mineralised system. Although the Tritton deposit was discovered in the mid 1990s and mining commenced in 2004 the geological understanding is continually evolving.  In recent years the geology has changed at depth and as the mining front has exposure to more of the geology, it has also allowed a greater understanding of the mineralised system.

The deposit has transitioned from a tabular north/south trending system to an elongated east-west trending ellipsoid, with the deposit thickness increasing from a minimum of 20 metres to more than 80 metres in places. Copper grades have steadily decreased with the increasing depth. As the mineralised system has changed with increasing depth, internal high grade copper shoots have been identified within the Measured Mineral Resource classified sections of the Tritton deposit. It appears that the high-grade shoots may extend deeper within sparsely drilled sections of the deposit, with further work planned in the coming year to better define their potential to be mined.

Several drill programs have been completed targeting down plunge extensions (below 4,000m.RL level) to the Tritton mineralised system.  Notable assay results include:

    • TRGC1001 21.50m @ 2.26% Cu;
    • TRGC1009 17.00m @ 1.57% Cu;
    • TRGC1010 7.00m @ 5.26% Cu and 6.80m @ 1.82% Cu;
    • TRGC1011 2.06m @ 2.28% Cu; and
    • TRGC1023 23.40m @ 1.86% Cu.

Within the larger 2,000 metre (horizontal) Tritton – Budgerygar mineralised corridor there are numerous drill hole intersections peripheral to both deposits which contain elevated (+0.5% Cu) intersections over multiple metres. The sparsely drilled North Wing prospect immediately north of Tritton, is considered highly prospective and drilling is planned to target extensions to the sulphide mineralisation previously intersected.

Following a focus on geological interpretation work undertaken during FY2020, the Tritton geology model was updated to reflect the changing geology at depth below the 4,300mRL. Whilst the macro scale geometry change was clear, controls on the internal distribution of high-and-low grade copper mineralisation and their spatial continuity has taken longer to unravel.

The updated geology model provides an improved understanding of the potential grade profile below the current mining front (4,110mRL level) and the spatial location of potential higher-grade corridors. Drill coverage becomes progressively sparse down to the limit of drill coverage at the 3,850mRL level.

Importantly, the Tritton mineralised system remains open at depth with drill holes continuing to exhibit high grade and low grade copper horizons. The revised geological model will be used to assist with a FY2021 drill program designed to target extensions to the known Tritton mineralisation down plunge from current drilling. Downhole electromagnetic (DHEM) surveying will be completed on some drill holes to assist with vectoring toward mineralisation.

Budgerygar Deposit

The Budgerygar deposit is located approximately 600 metres along strike (north) from Tritton. The mineralised system is defined by four discrete lodes which cover a footprint of 250 metres (strike) by 800 metres down plunge. An exploration access drive is currently being developed toward the deposit to provide a drill platform for resource definition drilling planned to commence in FY2021. Planned drilling off the exploration drive will target the upper extensions of all four lodes within a 30 metre vertical window from 5,250mRL to 4,900mRL.

Drilling will also target sporadic copper intersections in the footwall the Mineral Resource from historical drill holes completed in the late 1990s to early 2000’s.

 

Tritton and Budgerigar deposits showing current underground planned development and down plunge opportunities.

Murrawombie – Avoca Tank Corridor

Murrawombie

At the Murrawombie deposit, underground drilling continued throughout the year with a focus on extending the mineralised footprint further along strike and down plunge. Towards the end of 2019, underground drilling was completed targeting extensions to the Indicated Mineral Resource along strike (north) and down plunge. Drilling in both directions intersected copper sulphide mineralisation, highlighting the potential to increase the Mineral Resource base.

Drilling results announced on 27 February 2020 (refer to a previous ASX Announcement dated 27th February 2020 “Exciting Drilling Results at Murrawombie”), targeting the periphery of the main mineralised body (102 lode) and down plunge extensions beneath the Indicated Mineral Resource.  Significant assay intercepts down-plunge include:

    • MWGC509 15.25m @ 3.07% Cu;
    • MWGC507 34.70m @ 2.06% Cu;
    • MWGC500 4.60m @ 2.63% Cu; and
    • MWGC496 17.30m @ 2.05% Cu.

Long section view showing drillhole pierce points through the Murrawombie main and emerging lobe

This drill program has extended the down plunge extents a further 50 metres beyond the June 2019 Mineral Resource outline and mineralisation remains open down plunge.

A total of 80 drill holes were completed during FY2020, with a majority intersecting sulphide mineralisation. Drilling through the main mineralised bodies (lode 102 and 108) resulted in the delineation of additional mineralisation along strike and down plunge. The majority of the drill holes were extended further into the hanging wall (HW) testing extensions / continuity to mineralisation previously intersected beyond the 102 and 108 lodes.

In total, eight drill holes were completed in the first quarter of 2021, with six focused on constraining the known northern extents of the hanging wall (HW) lodes (111, 113 and 115 lodes). The remaining two drill holes targeted down plunge extensions below the southern margin of the HW lodes.

Drilling through the HW horizon consistently intersected copper sulphide mineralisation. Drilling density was sufficient to enable an updated geological interpretation which delineated three new copper sulphide lodes in the HW to the main Murrawombie lodes. The HW lodes are and exciting discovery which highlights the prospectivity of the field and potential to increase the Mineral Resource base with the delineation of new sulphide bodies from additional near mine exploration.

The first of two deep (~1,100 metre) diamond drill holes from surface commenced in September. Both drill holes are targeting the projected down plunge continuation of the Murrawombie mineralised system, 150 metres to 200 metres below the current footprint.

Following the completion of both drill holes down-hole electromagnetic surveys (DHEM) will be completed to detect for conductive bodies within a 200 metre radius from each drill hole.

Avoca Tank

The deposits discovered on the Tritton tenement package typically have a long down plunge extent and the same is expected to be true at the Avoca Tank deposit. Future exploration drilling of the deposit will be most efficient from an underground platform. However, to assist with feasibility studies, a small drilling program of up to 3 drill holes to test the vertical extension of the deposit is planned. This program has the aim of helping to improve the understanding of the deposit’s structural controls to optimise future underground drilling locations.

Kurrajong

The HP MLTEM survey completed over the Kurrajong prospect detected two strong bedrock conductors commencing at 400 metres below surface. The detection of the plates provided the impetus to commence a limited drill program testing the potential extents to mineralisation intersected from previous drilling at the prospect. The initial two holes (TKJD014 and TKJD015) targeted the interpreted mineralised extensions at 150 metres up and down plunge. Both drill holes intersected massive sulphides:

  • TKJD014 returned 19.4 metres @ 2.2% Cu; and
  • TKJD015 returned two intersections of 4.60 metres @ 5.1% Cu and 5.65 metres @ 2.5% Cu.

These results were encouraging enough for Aeris to extend the drill program with a further 12 drill holes completed in November 2018. The drilling program extended the limits of sulphide mineralisation to 300 metres along strike and 1,100 metres down plunge.

Within the large sulphide envelope, an exploration target was defined ranging from 3 to 4 million tonnes at 1.5% to 2.0% copper.

Regional Geology Compilation

Regional Geology Compilation

To date, the majority of the on-ground exploration within the Tritton tenement package has been focussed within the southern half, along the prospective “Budgery Sandstone” corridor between the Budgery and Avoca Tank deposits.

Exploration of the northern part of the tenement package has been limited until the recently completed airborne EM surveys, with previous exploration limited to one airborne EM survey flown in the late 1990s. A recent review of the historical EM survey data from the late 1990s indicated it was largely ineffective in detecting concealed mineralisation below surface.

Recent regional mapping and follow-up geophysical interpretation over the northern half of the tenement package was successful in identifying the continuation of the Budgery Sandstone unit for a further 65 kilometres than originally thought. Additionally, the prospective corridor was interpreted to extend a further 40 kilometres further northwest, into an area now covered by EL 8810.

EL8810 was granted in late 2018 and is located adjacent to the north-west corner of the current Tritton tenement package. The new tenement, covering an area of 296km2, brings the total Tritton tenement package to 2,160km2, covering the known 155-kilometre strike extent of the Budgery Sandstone unit.

An initial trial airborne EM (AEM) survey was flown over selected areas of the Tritton tenement package in January 2018 to determine the effectiveness of this method in the detection of potential bedrock conductors. The survey was successful in identifying 4 new potential bedrock conductors along the northern margin of the tenement package.

A second AEM survey covering the remainder of the under-explored northern half of the tenement package (617km2 – excluding EL8810) was flown in January 2019 and identified a further 25 EM anomalies, including 9 high-priority targets. The airborne EM survey was flown using the SKYTEMTM 312 EM system, which is designed and optimised for deep conductor bodies. This system enabled exploration to quickly and cost-effectively identify potential copper sulphide mineralisation.

A ground based moving loop electromagnetic (MLTEM) surveying was completed over the AEM conductive bodies.  The MLTEM survey was designed to filter out the AEM anomalies which are legitimate bedrock conductors from those which are related to noise or near surface cover responses.

Aeris’ exploration focus on the Tritton tenement package within FY2021 is principally within the northern half of the tenement package, focusing conductive bodies detected from AEM and MLTEM geophysical surveys.

Caribou Prospect

 

Plan view showing the airborne EM survey coverage and potential bedrock conductors through the northern extents of the Tritton tenement package.

Plan view showing the airborne EM survey coverage and potential bedrock conductors through the northern extents of the Tritton tenement package.

A modest drill campaign, totalling three drillholes was completed within the Murrawombie to Avoca Tank prospective corridor following the completion of a geological review and additional MLTEM survey data.  Two drillholes targeted geophysical anomalies, one 1.5 kilometres north west from Murrawombie and the other 500 metres south of Avoca Tank. The third drillhole targeted down plunge extensions to mineralisation at the Caribou prospect (located within the Larsens – Northeast mining province).    Previous exploration drilling activities at the Caribou prospect intersected variable amounts of copper sulphide mineralisation with several encouraging results including;

  • TCBD007 6.00m @ 3.45% Cu (true thickness approx. 4m);
  • TLRNM006 4.70m @ 3.05% Cu (true thickness approx. 2m);
  • TLRNM002 28.80m @ 1.56% Cu (true thickness approx. 16m) including 15.5m @ 2.03% Cu (true thickness approx. 10m).

Drillhole TCBD010 was drilled targeting 100 metres down plunge to the known mineralised system.  The drillhole intersected a broad zone of pyrite +/- chalcopyrite disseminations and minor stringer veins (total sulphide content <5%) over an approximate 40 metre interval (assays pending).  Strong chlorite alteration was observed throughout the sulphide interval which is commonly in close association to mineralised systems elsewhere in the region.

A downhole EM (DHEM) survey was completed down TCBD010.  The DHEM survey detected an off-hole conductor above the drillhole which corresponds with the mineralised zone intersected from previous drilling.  The modelled plate extends further down plunge than previously modelled DHEM plates (combined total plunge extent 200 metres).

The drill results and modelled DHEM plates at the Caribou prospect are encouraging and may reflect a similar mineralised system to the Larsens deposit (~1Mt @ +2% Cu), located 300 metres to the west.

The remaining two drillholes did not intersect sulphide mineralisation.  MNWD002 targeting an IP anomaly north west from Murrawombie intersected a graphitic shear at the target depth.  Drillhole TAVD002 targeted a potential MLTEM conductor south of Avoca Tank.

 

Long section view showing drillhole pierce points through the Caribou prospects.