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High-Res Biogeochemical
Exploration Under Deep
Cover - a Tanami case study
AIG – BEDG Presentation, 2 July 2013
By Ian Hodkinson
Disclaimer This presentation has been prepared by Murrumbo Ltd (Murrumbo). The information contained in this presentation is a professional opinion
only and is given in good faith at the time of preparation of this document.
Certain information in this document has been derived from third parties and although Murrumbo has no reason to believe that it is not
accurate, reliable or complete, it has not been independently audited or verified by Murrumbo. Any forward‐looking statements included in
this document involve subjective judgement and analysis and are subject to uncertainties, risks and contingencies, many of which are
beyond the control of, and maybe even unknown to, Murrumbo. In particular, they speak only as of the date of this document, they assume
the success of Murrumbo’s strategies, and they are subject to significant regulatory, business, competitive and economic uncertainties and
risks. Actual future events may vary materially from the forward looking statements and the assumptions on which the forward looking
statements are based. Recipients of this document ("Recipients") are cautioned to not place undue reliance on such forward‐looking
statements.
Murrumbo makes no representation or warranty as to the accuracy, reliability or completeness of information in this document and does not
take responsibility for updating any information or correcting any error or omission which may become apparent after this document has
been issued. To the extent permitted by law, Murrumbo and its officers, employees, related bodies corporate and agents ("Agents")
disclaim all liability, direct, indirect or consequential (and whether or not arising out of the negligence, default or lack of care of Murrumbo
and/or any of its Agents) for any loss or damage suffered by a Recipient or other persons arising out of, or in connection with, any use or
reliance on this presentation or information.
Competent Person Statement The exploration data and results contained in this presentation are based on information reviewed by Mr Ian Hodkinson, a member of the
Australian Institute of Geoscientists. He is Exploration Director of the Company and has sufficient experience which is relevant to the styles
of mineralisation and types of deposits under consideration and to the activity which he is undertaking to qualify as a Competent Person as
defined in the December 2004 edition of the ‘Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore
Reserves’ (the JORC Code). Mr Hodkinson has consented to the inclusion in this presentation of the matters based on his information in
the form and context in which it appears.
TANAMI PROJECT
MURRUMBO BACKGROUND
Murrumbo Limited is an unlisted, privately-
funded, Australian-based, precious and
strategic metal exploration company
operating in the world-class mineral districts
of the Lachlan Fold Belt in New South Wales
and the Tanami Province in Western
Australia.
• Chris Vose - BE Mech (Hons) Q’ld.
• Ian Hodkinson - MSc Leics., MAIG,
RPGeo.
• Andrew Tunny – BCom, BEcon Q’ld MTM
Syd GradDipCA ICAA CA
TANAMI PROJECT
TANAMI GOLD NL - ACKNOWLEDGEMENT
Murrumbo Limited wishes to acknowledge the cooperation and assistance of Tanami
Gold NL and numerous individuals at Coyote Mine and the Central Tanami site.
TANAMI PROJECT
Location
• WA
• Five ELs
• Granted -886km2
• Applications -291km2
• Total 1177km2
TANAMI PROJECT
TANAMI PROJECT
Company Deposit Tonnes (Mt) Grade (g/t Au) MOz Au
Newmont Callie 14.5 4.7 2.190
Tanami Gold Groundrush 6.7 4.8 1.034
ABM Resources Buccaneer 15.3 2.23 1.097
Tanami Gold Coyote 0.8 12.7 0.327
ABM Resources Old Pirate 1.9 10.1 0.617
The Tanami - Au ‘Elephant Country’
The Tanami – Seeing Through the Cover
The Traditional Approach… • Geophysics - aeromagnetics
• Soils: BLEG, lag, MMI
• Drill, drill, drill, drill, drill….$$$$$
• Time for a new approach…
m
TANAMI PROJECT
The Coyote Saga – a discovery case study
1988 – ACM, Cactus Prospect, BL103, 4m @ 2.13 g/t Au - 7.3km WSW
1987 – Ellis & Wellington Resources, new tenement, E80/994
1988 – CRA JV, no work done
1991 – Perilya JV, no work, tenement surrendered
1991 – Billiton, E80/1483, new tenement
1993/94 – Billiton regional soil sampling - but not at Coyote
1994/95 – Acacia, 2ppb Au in soil sampling lines 26 & 27 - 2km W
1995/96 – Acacia, RAB drilling – but not at Coyote
1996/97 – Acacia, more RAB drilling, Line 67 - 1km too far W
Line 68 - too short 0.9km NNE
1997/98 – Acacia, more RAB drilling, BRPH1557, 12ppb Au - 800 m SW
BRPH1558, 10ppb Au - 525 m WSW
1998/99 – Acacia, RAB hole BRPH1735, 3m @ 8.81g/t Au - Bingo !
Coyote was discovered almost 8 years after the tenement was applied for. The
dispersion train was intersected during the fourth drilling programme … $$$$
A decent geochemical programme would have found it a lot earlier …
TANAMI PROJECT
Recent Developments in the Tanami
• Predictive Targeting, CET 2011
• ‘New’ mineralisation style – ABM’s Buccaneer
• Biogeochemical Sampling PhD, Nathan Reid, 2008
TANAMI PROJECT
Predictive Targeting
• MERIWA / CET, Project
M389, 2011 ‘A four-
dimensional interpretation of the
geological evolution of the
Proterozoic West Tanami region
and its mineral systems
• 32 Priority Target Areas
• ‘Decision Support Aid’
not a Treasure Map
• Predictable or self-
fulfilling ?
TANAMI PROJECT
New Mineralisation Style
• ABM’s Buccaneer Prospect
• NFM RAB discovery
• Acquired early 2010
• ‘New’ mineralisation style
• Stockwork, low-grade
• Large – 128 Mt @ 0.65g/t Au
• 2.7Moz Au
• Syeno-granite hosted
• Sulphide Cu zone, Ag & Mo
After ABM Resources
TANAMI PROJECT
Biogeochemical Sampling
• Long established method in
Canada & Scandinavia
• Slow acceptance in Australia
despite ideal conditions
• Arid climates → ideal deep
rooted species
• Nathan Reid, PhD, Adelaide
University, 2008 at Coyote
(WA) and Titania (NT)
• Soft Spinifex preference
After Nathan Reid
TANAMI PROJECT
Spinifex Sampling
• Species - Triodia pungens • Wide distribution
• Virtually ubiquitous
• Deep rooted >30m
• Easily and quickly harvested
• Hedge clippers
• Spines or ‘awls’
• Calico bags (~400 gms)
• Geochemically Responsive • Major cations
• Pathfinders
• Precious metals
• Base metals
After Nathan Reid / CRC LEME
TANAMI PROJECT
Spinifex Sampling - Coyote Prospect, WA
• Anomalous Au, As, Zn, also S – raw samples
After Nathan Reid
TANAMI PROJECT
Spinifex – Maturity and Seasonality
• Bushfires → maturity variations
K, B, Li, Rb (Al, Cs, P etc.)
• Seasonality
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Spinifex Sampling – practical problems
• Species identification
• Sticky - contamination issue
• OHS issues
• Volume problem
Spinifex Sampling – some solutions
• Increase sample volume, numerous plants (>5), ~400gms
• Clean up sample → ~30gms
• Consult the experts → ashing, the critical step
TANAMI PROJECT
Colin Dunn
Helen Waldron
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Ashing Methodology
• Ashing at Acme Laboratories, Vancouver, Canada ~30g for
16 hours at 475°C in Al pans
• Ash yield ~5% = ~20x metal increase most elements
• Ash aliquot 0.25 g → HNO3 + Aqua Regia digestion
• ICP-MS multi-element analysis:
• Au, Ag, Hg, Re, Pd, Pt (ppb), Mo, Cu, Pb, Zn, Ni, Co, Mn,
As, U, Th, Sr, Cd, Sb, Bi, V, La, Cr, Ba, B, Sc, Tl, Se, Te,
Ga, Cs, Ge, Hf, Nb, Rb, Sn, Ta, Zr, Y, Ce, In, Be, Li (ppm),
Ca, Fe, Al, Na, K, Mg, P, S, Ti (%)
• QA/QC critical, ash standards, field duplicates, laboratory
duplicates, blanks etc.
TANAMI PROJECT
Au nucleation → nugget effect between/within plants
• BLAC1875 Spinifex Biogeochemical ‘Standard’
• 33 samples – field duplicates
• Poorly behaved statistically for Au, better for Cu
• False negatives very common
• False positives rare (non-existent - contamination ?)
0
2
4
6
8
10
12
0.1
2
0.8
2
1.5
2
2.2
2
2.9
2
3.6
2
4.3
2
5.0
2
5.7
2
6.4
2
7.1
2
Mo
re
Fre
qu
en
cy
Au ppb
Au ppb
Frequency
0
1
2
3
4
5
6
7
8
9
10
32 36 40 44 48 52 56 60 64
Mor
e
Freq
uenc
y
Cu ppm
Cu ppm
Frequency
Gold in bark
TANAMI PROJECT
But does it work ?
TANAMI PROJECT
Validation - ash (A) vs. -80# soils (S) at Test Site C (NT)
0
10
20
30
40
50
60
Au p
pb
Test Site C North Line - Au
AuAppb
AuSppb
0
100
200
300
400
500
600
700
800
Zn p
pm
Test Site C North Line - Zn
ZnA ppm
ZnS ppm
0
0.5
1
1.5
2
2.5
3
3.5
4
As
pp
m
Test Site C North Line - As
AsA ppm
AsS ppm
0
50
100
150
200
250B
a p
pm
Test Site C North Line - Ba
BaAppm
BaSppm
TANAMI PROJECT
What are we looking for ?
• Au – high grade (>10g/t), low tonnage, underground
• Au – low grade (<5g/t), high tonnage open cut
• REE alkaline intrusive style
• U/REE – Killi Killi Hills, unconformity type
• U – ‘roll front’ or calcrete style in cover sediments
• Base metals ?
TANAMI PROJECT
Tanami Geology & Prospect Locations
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Atlantic Prospect - Location
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Atlantic Prospect – Ashed Spinifex Au results
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Anomaly Magnitude Comparison – Test Sites v.
Prospects Location Au ppb
in ash
Ag ppb
in ash
As ppm
in Ash
Pt ppb
In Ash Comment
Test Site A 29.5 19 14.8 3 5m laterite cap
Test Site B 67.5 81 2.3 5 Minimal cover
Test Site C 53.3 28 3.4 8 3 to 10 m sand cover
Test Site D 12.6 31 23.3 14 1.5 to 6 m sand cover
Atlantic East 17.2 76 1.2 9 19 to 35 m sand/colluvial cover
Atlantic W 41.0 144 2.2 21 28 to 86 m sand/colluvial cover
Atlantic Far W 13.4 24 2 9 50 to 70 m sand/colluvial cover
Dolerite 9.1 49 19.2 11 Minimal cover
TANAMI PROJECT
Dolerite Prospect - Location
TANAMI PROJECT
Dolerite Prospect – Ash Geochemistry – As (ppm) •
•
•
•
•
•
•9ppb Au
5.8ppb Au
6.3ppb Au
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Blondie Prospect - Location
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Blondie Prospect – Lag Geochemistry Cu (ppm)
TANAMI PROJECT
• Gabbroic intrusives
• TMI magnetic anomalies
• Afmeco - rock GT0072
• Hematite quartz breccia • 76.5 ppm U
• 273 ppm Nd
• 593 ppm Ce
• 589 ppm Cu
GT0072
Gabbro
Gabbro
E80/4801 Selby – the forgotten corner of the Tanami
TANAMI PROJECT
E80/4801 Selby – REE Geochemistry
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REE ratio review
courtesy of Professor
Ken Collerson
• Geographe Lag Anomaly • 380 ppm Cu
• 27 ppm As
• 63 ppm Pb
GT0072
Gabbro
Gabbro
E80/4801 Selby – the forgotten corner of the Tanami
Cu
ppm
TANAMI PROJECT
THANK YOU
TANAMI PROJECT