Thick Intersections of Strong to Intense Copper Mineralisation at Bluebird
- Significant copper mineralisation intersected at Bluebird East, a potential repeat of the high-grade Bluebird copper-gold discovery, with more drilling to come.
- Strongly mineralised intersections produced in latest drilling phase at the high-grade Bluebird copper-gold discovery, including immediate extensions and new targets across an expanded 1.5km strike-length (see Appendix 1 for mineralisation descriptions):
Drilling of the exceptionally high-grade gold-copper zone on the western side of Bluebird has intersected 63m of hematite alteration with 48m of strong to intense copper mineralisation in BBDD0045, including zones of massive chalcopyrite (see Figures 1,2,3). Drilling of the shallow eastern extensions of Bluebird has intersected thick zones of copper mineralisation including 111m of hematite alteration with 47m of strong copper and bismuth (indicator of gold) mineralisation in BBDD0042 (see Figures 1,2,4). Drilling of the Bluebird East target has intersected a 24m zone of chlorite-silica-hematite alteration and sulphide mineralisation including 8m of copper mineralisation (chalcocite, malachite) in BBDD0043. This intersection is highly significant, as it could represent the upper part of a repeat of the Bluebird high-grade copper-gold mineralised zone. Further drilling will now test down dip and to the west of this drill hole (see Figures 1,2,5).
- The new western intersections are on a previously un-drilled section (448,300mE) to the west of recent bonanza gold with copper results (see longitudinal projection, Figure 2) which included:
17.95m @ 11.08 g/t Au, 2.66% Cu from 131m downhole in BBDD00261,
incl. 15.9m @ 12.45 g/t Au, 2.91% Cu from 131.8m,
incl. 5m @ 38.6 g/t Au, 6.11% Cu from 142.7m incl. 2.25m @ 64 g/t Au, 9.57% Cu.
- Over 3,000m of RC and diamond drilling now completed in this latest phase of the Stage 3 program, with assay results from strong to intensely mineralised holes expected in December-January.
Tennant Minerals acting Chairman Neville Basset commented:
“We are very encouraged by the visual indications from the latest phase of drilling at our high-grade Bluebird copper gold discovery in the Northern Territory.
Not only have we intersected thick intersections of strong to intense copper, and possibly gold mineralisation, in the western high-grade gold-copper zone at Bluebird, but we may also have discovered a repeat of the high-grade Bluebird discovery associated with geophysical targets at Bluebird East.
Identifying a repeat of this exceptional discovery could significantly enhance the economic potential for Bluebird to be developed as a high-grade, stand-alone copper-gold mine.”
15 November 2023 - Tennant Minerals Ltd (“Tennant” or “the Company”) (ASX:TMS) is pleased to announce strongly mineralised intersections in multiple targets from the latest phase of drilling at the high-grade Bluebird copper-gold discovery, located within the Company’s 100%-owned Barkly Project, 40km east of Tennant Creek in the Northern Territory (see Appendix 1 for descriptions of mineralisation).
Cautionary note regarding visual estimates:
In relation to the disclosure of visual mineralisation above, within the text below and as detailed in Appendix 1, the Company cautions that visual estimates of oxide, carbonate and sulphide mineralisation material abundance should never be considered a proxy or substitute for laboratory analyses. Laboratory ICP-MS and ICP-OES analyses are required to determine widths and grade of the elements (e.g., copper, Cu) associated with the visible mineralisation reported from preliminary geological logging. The Company will update the market when laboratory analytical results are received and compiled. Assay results for the majority of this program are expected to be available within the next 2-6 weeks. Target mineral abundances are estimated along with general geological descriptions.
A further 15 reverse circulation (RC) and diamond drill-holes, for just over 3,000m, have been completed during September and October during the second phase of the Stage 3 drilling program at Bluebird. Assay results are pending with the majority of results expected to be available within the next 2-6 weeks.
The current drilling is testing three key target areas across a 1.5km expanded footprint at Bluebird, including shallow eastern extensions of the copper-gold mineralisation; a new section in the exceptionally high-grade gold-copper zone on the western side of Bluebird, and initial holes into the Bluebird East target. Drilling completed to date, and planned holes, are shown with gravity inversion on Figure 1 below:
Figure 1: Bluebird in plan projection with 3D gravity inversion model, current progam and planned drilling
Strongly mineralised intersections have been produced in the latest phase of drilling from:
i) The Bluebird Western High-Grade Gold-Copper Zone:
The recent drilling included two drillholes in the western high-grade gold-copper zone at Bluebird, on a previously un-drilled section, 448,300mE (see Figure 2 and cross section, Figure 3). Both holes intersected thick zones of strong to intense copper mineralisation (see Appendix 1 for descriptions of mineralisation):
- 63m of hematite altered ironstone with 48m of strong to intense copper mineralisation, including massive chalcopyrite intervals in BBDD0045, and, above this hole.
- 47.5m of hematite altered ironstone with 36m of strong to intense copper mineralisation, including chalcopyrite, chalcocite and native copper in BBDD0046.
Figure 2: Bluebird longitudinal projection showing key copper-gold intersections and new strongly mineralised intersections at Bluebird Extension, East and Western Zone
Figure 3: Cross-section 448,300mE with new drillholes BBDD0045-46 showing hematite and copper intersections
These new intersections are down-plunge to the west of the recent exceptional gold and copper intersection in BBDD00261 of 17.95m @ 11.08 g/t Au, 2.66% Cu from 131m downhole, including 5m @ 38.6 g/t Au, 6.11% Cu. The new holes have also extended the zone of massive chalcopyrite sulphide mineralisation to the west of previous drillhole BBDD00185, which intersected 30.5m @ 6.2% Cu, 6.8 g/t Au from 153.6m including 17.8m @ 5.2% Cu, 11.5 g/t Au from 153.6m and 16.1m @ 10.5% Cu and 0.44 g/t Au from 164.9m (see longitudinal projection, Figure 2).
ii) The Bluebird Shallow Eastern Extensions Zone:
New drilling to extend the shallow up-plunge eastern extension of Bluebird has confirmed continuity and extended the mineralisation to shallower depths. Key mineralised intersections (see Appendix 1 for descriptions of mineralisation) on section 448,500mE (see Figure 2 and cross section, Figure 3) include:
- BBDD0042 which intercepted 111m of hematite-silica alteration of the host ironstone formation and includes 46.8m of strong copper mineralisation (5% to 30% chalcocite, bismuth sulphides, minor bornite, chalcopyrite and native copper), and,
- BBRC0026 which intersected 22.5m of hematite alteration including 12.5m of copper mineralisation (chalcocite, bornite, native copper).
Figure 4. Cross-section 448,500mE, with new strongly mineralised intersections in BBDD0042 BBRC0026
Previous significant intersections in the eastern extension remain open at depth and include 17.4m @ 2.18% CuEq* (1.58% Cu, 0.06 g/t Au, 0.25% Bi) in BBDD00332 (see Figures 2 and 4) including 5.44m @ 3.66% Cu, 0.1 g/t Au including 3.2m @ 1.62% Cu, 0.08 g/t Au) (*refer Appendix 2 for copper equivalent (CuEq) calculations).
The new drilling has defined the Bluebird east extension mineralisation and extended the zone to within 60m of the surface (see Figure 4), which may allow open pit mining to access the Bluebird Cu-Au zone.
iii) The Bluebird East Target
Drilling which targeted coincident gravity highs (ironstone) and IP-resistivity lows, 250 to 500m east of the main Bluebird discovery2,3, has intersected thick ironstone and hematite alteration, including significant copper mineralisation (see Appendix 1 for descriptions of mineralisation).
New diamond drillhole BBDD0043 intersected thick ironstone in the modelled position then passed into a 24m zone of hematite-chlorite-silica alteration from 252.8m downhole, with significant copper mineralisation (visible chalcocite and malachite on fracture surfaces) over 8 metres (see Figure 5).
Figure 5. Cross-section 448,800mE, Bluebird East, with significant hematite and copper intersection in BBDD0042
The intersection of copper mineralisation in the footwall of the Bluebird ironstone at Bluebird East is highly significant, as it may indicate the discovery of a repeat of the Bluebird high-grade copper-gold zone. Further drilling will now test down-plunge extensions of this zone extending west, where the ironstone and mineralisation are indicated to extend by gravity and IP resistivity modelling (see Figures 1 and 2).
The potential discovery of a repeat of Bluebird at Bluebird East offers the potential to double the footprint of the copper-gold mineralised zone (see Figure 2).
NEXT STEPS
Assay results are pending for all 15 holes drilled as part of this drilling phase to date. It is anticipated that the majority of these results will be available within the next 2-6 weeks.
Further drilling will now test the down-plunge extensions of the Bluebird East target (see Figure 2) before the drilling is completed prior to the northern wet season.
Other targets remaining to be tested include down-plunge extensions of the main copper-gold zone and geophysical targets at Bluebird West. Northern Territory government co-funding will be sought to test the deeper targets and other regional targets such as Perseverance North and at Babbler (see Figure 6).
Bulk metallurgical samples will be generated from the strongly mineralised holes, BBDD0045 and 0046, which tested the high-grade western part of the Bluebird deposit. This work will include flotation tests for sulphide mineralisation as well as gravity tests for native copper and gold.
Mineral Resource modelling will be carried out after receipt of results from the current phase.
ABOUT THE BARKLY PROJECT AND THE BLUEBIRD COPPER-GOLD DISCOVERY
The high-grade Bluebird copper-gold discovery is located within the Company’s 100% owned Barkly Project, on the eastern edge of the richly endowed Tennant Creek Mineral Field, which produced over 5.5Moz of gold and over 700kt of copper from 1934 to 20056 (see Figure 6 below).
Figure 6: Location of the Barkly Project and major historical mines in the Tennant Creek Mineral Field
The mineralisation intersected at Bluebird is typical of the high-grade copper-gold orebodies in the Tennant Creek Mineral Field. The high-grade mineralisation is associated with intense hematite alteration and brecciation with secondary malachite (copper-carbonate) in the upper parts as well as native copper, which transitions to primary sulphide mineralisation at depth e.g. chalcocite, bornite and chalcopyrite.
Drilling to date has identified copper-gold mineralisation at Bluebird over a 500m strike length and to over 250m depth. The mineralisation remains completely open in all directions (Figure 2).
The Company has the dual approach of defining the Mineral Resource potential of the Bluebird discovery while also testing other key targets in the Bluebird-Perseverance corridor based on gravity, magnetics and IP resistivity survey modelling7.
Table 1: Bluebird Stage 3 drillhole details
Hole #
Dip°
Az Grid°
GRID
GRID_N
RL
Pre-Collar/RC
DDC
Depth
Hole Type
BBDD0026
-60
0
448322
7827056
332
122.7
96.7
219.4
DD
BBDD0027
-60
0
448280
7827060
332
101.5
115.9
217.4
DD
BBDD0028
-65
0
448280
7827010
330
122.0
-
122.0
DD
BBDD0028A
-67
352
448278
7827005
332
147.2
213.2
360.4
DD
BBDD0029
-60
0
448280
7827085
332
71.8
108.7
180.5
DD
BBDD0030
-60
357
448240
7827060
332
96.2
122.8
219.0
DD
BBDD0031
-53
358
448320
7827060
332
-
204.3
204.3
DD
BBDD0032
-53
0
448500
7827050
330
78.1
178.9
257.0
DD
BBDD0033
-53
358
448500
7827010
332
71.6
147.1
218.7
DD
BBDD0034
-53
357
448580
7827015
331
72.0
269.1
341.1
DD
BBDD0035
-55.5
353
448580
7827035
332
29.5
136.7
166.2
DD
BBDD0036
-54
359.5
448660
7827050
333
-
163.5
163.5
DD
BBDD0037
-55
356.6
448660
7827032
331
51.1
138.7
189.8
DD
BBDD0038
-55
0
448460
7827045
332
74.8
82.0
156.8
DD
BBDD0039
-55.5
356.
448547
7827028
330
59.9
70.8
130.7
DD
BBDD0040
-54.9
356
448980
7827002
330
80.7
272.8
353.5
DD
BBDD0041
-51.5
356
448980
7827068
330
119.8
159.3
279.1
DD
BBDD0042
-56.6
355
448500
7827030
330
66.0
137.9
203.9
DD
BBDD0043
-51.2
355
448800
7827019
330
98.3
248.9
347.2
DD
BBDD0044
-52.7
354
448200
7827025
330
144.0
-
144.0
DD
BBDD0044A
-57.3
345
448200
7827020
330
143.6
129.0
272.6
DD
BBDD0045
-79.5
357
448297
7827093
330
78.0
153.9
231.9
DD
BBDD0046
-79.5
357
448297
7827033
330
78.0
102.6
180.6
DD
BBRC0021
-52
359
448,321
7,827,079
331
150
-
150
RC
BBRC0022
-54
356
448462
7827065
332
106.2
28.4
134.6
RCD
BBRC0023
-56.2
357
448579
7827052
332
174.0
-
174.0
RC
BBRC0024
-50
357
448571
7827076
332
126.0
-
126.0
RC
BBRC0025
-55
358
448615
7827085
332
126.0
-
126.0
RC
BBRC0026
-50.5
0
448502
7827071
332
54.0
71.6
125.6
RCD
BBRC0027
-50.3
353
448540
7827066
332
126.0
-
126.0
RC
Authorised for release by the board of directors.
***ENDS***
For enquiries please contact:
Stuart Usher
Company Secretary
M: +61 (0) 499 900 044
Andrew Rowell
White Noise Communications
M: +61 (0) 400 466 226
REFERENCES
1 19/07/2023. Tennant Minerals (ASX.TMS): “Drilling Doubles Strike Length of Bluebird copper-Gold discovery”
2 15/08/2023 Tennant Minerals (ASX.TMS): “New Results Confirm Eastern Bluebird Extension Discovery”
3 15/05/2023. Tennant Minerals (ASX.TMS): “Drilling Resumes at high-Grade Bluebird Cu-Au Discovery”
4 01/9/2023 Tennant Minerals (ASX.TMS): “New Bluebird Drilling to Target Triple the Strike Length”
5 08/02/2023. Tennant Minerals (ASX.TMS): “Spectacular Bluebird Drill-Hit 30.5m @ 6.2% Cu, 6.8 g/t Au”.
6 Portergeo.com.au/database/mineinfo. Tennant Creek - Gecko, Warrego, White Devil, Nobles Nob, Juno, Peko, Argo.
7 25/08/2022. Tennant Minerals (ASX. TMS): “Standout Geophysical Targets to Replicate Bluebird Cu-Au Discovery”.