"Finding the NEXT Broken Hill". Mark Dugmore, Director, BHT Minerals. Technical presentation at 2015 Broken Hill Resources Investment symposium.

1. Discovering
the
NEXT
Broken
Hill
Mark
Dugmore
Broken
Hill
Symposium
27
May
2015

2. The
in-­‐ground
value
of
the
(pre-­‐mined,
pre-­‐eroded)
Broken
Hill
deposit
at
current
metal
prices
is
AUD$165
Billion
Deposit
of
NaLonal
Interest
-­‐
Town
of
NaLonal
Heritage
Assumes:
300Mt
@
148
g/t
Ag,
18.5%
combined
Pb+Zn.
Source:
O’Brien
et
al,
2015

3. § Broken
Hill
is
among
the
great
ore
deposits
of
the
world
§ Cannington
is
the
world’s
largest
primary
producer
of
silver
~30
Moz
annually
Broken
Hill-­‐type
Deposits.
A
big
prize!
Mt
Ag
g/t
Zn
%
Pb
%
Ag
Moz
Zn
mt
Pb
mt
Broken
Hill
300
148
8.5
10.0
1,430
26
30
Cannington
44
538
4.4
11.6
760
2
6

4. Only
Five
‘Large’
BHT
Mines
around
the
World
Large
‘single’
deposits
dominaLng
a
district
are
the
norm.
Lower
discovery
risk
exists
in
NEW
districts.

5. SchemaLc
Broken
Hill
Type
Environment
Host
quartzofeldspathic
gneisses,
minor
amphibolite
*Fe-­‐Mn-­‐Ca-­‐rich
‘iron
fm’
Silica
±
garnet,
sillimanite,
K-­‐feldspar
Si
altera>on,
thin
exhalites
±
garnet,
gahnite
Bif
photo
courtesy
Steve
Walters
K/Na
>
10.
Whole
rock
Pb
to
300ppm
500m

6. How
do
you
airact
a
BHT!

7. Follow
the
Eastern
Cratons
Margin
§ BHT
deposits
occur
on
the
E
edge
of
the
Precambrian
§ IdenLficaLon
of
a
NEW
terrane
is
essenLal
for
a
new
discovery
§ Woodmurra
is
a
NEW
terrane
Woodmurra

8. MagneLcs
show
the
Craton
Margin
§ Inferred
‘pop-­‐up’
block
of
Broken
Hill
Gp
equivalent
§ Leading,
E
edge
of
craton
-­‐
magneLcally
acLve
§ PaleoProt
to
MesoProt
metamorphic
terrane
Woodmurra
Olympic
Dam
Broken Hill

9. Woodmurra
Project
-­‐
Geology
Outcrop
(to
Sth
of
project)
§ Paleoprot
volcano-­‐sedimentary
package
§ Age
≡
Lower
Eastern
Succession
(???
top
of
Lower
Willyama
Supergroup)
§ StraLgraphically
below
BH
&
Cannington
Drillholes
(to
SE
of
project)*
§ MetasomaLsed
qfs
gneiss/amphibolite
§ Ca-­‐Mn-­‐Fe-­‐P-­‐F
rich
assemblages
*

10. Geophysicists
ONE
(1)
–
Geochemists
NIL
(0)

11. MagneLcs
–
Broken
Hill
• Lower,
magneLc
oxidised
felsic-­‐
dominant
package
• Upper,
reduced
metasediment-­‐
dominant
package
(mag
quiet)
• ProspecLve
‘TransiLon
Sequence’
–
in
between
– DisLncLve
extensive
linear
responses
-­‐
amphibolites
– Short
strike
length
Mn-­‐P
‘bif’
Broken
Hill
Main
Lode

12. Cannington
TMI-­‐RTP
&
Falcon
Airborne
Gravity
3,000
m
Source:
Witherly
&
Mackee,
2015
TMI
AGG
• Overall
low
magneLc
host
package
• MagneLc,
short
strike
length
features
with
indicaLons
of
structural
complexity
• Cannington
ore
directly
associated
with
magneLte

13. § Broken
Hill
&
Cannington
lie
near
flank
of
a
large
gravity
high
§ Major
‘gravity
gradients’
evident
§ Woodmurra
shows
similariLes
Gravity
–
Flanks
of
Highs
are
Very
Important
Cannington
Broken
Hill
Main
Lode
Images at same scales
Woodmurra

14. Woodmurra
Project
–magneLcs
• Lower,
magneLc
package
?quartzo-­‐
feldspathic-­‐rich
• ProspecLve
‘transiLon’
package
with
short-­‐strike-­‐
length
(bif?)
and
disLncLve
linear
(amphibolite?)
features
• ‘Feature-­‐deficient’
upper,
?metasediment-­‐
dominated
package

15. Woodmurra
Project
–
gravity
• Dense
host
package
• ConcentraLon
of
amphibolites
???
• SpaLally
associated
with
max
development
of
BHT
mineralisaLon
and
lode
marker
horizons
at
BH

16. § Integrate
geophysical
data
from
SA
Gov’t-­‐funded
iniLaLves.
§ Regional
magneLcs
used
to
define
structure,
favourable
lithostraLgraphy
and
possible
direct
targets.
§ OLD
technology
(aeromagneLcs)
in
a
NEW
terrane
will
work.
§ Drill
a
range
of
short
strike
length
magneLc
anomalies.
§ Aim
to
i/sect
Pb-­‐Mn-­‐P-­‐F
anomalous
‘bif’
proximal
to
ore.
Woodmurra
Project
–
Strategy
under
cover

17. § IdenLficaLon
of
NEW
terrane
essenLal
for
discovery
of
a
BHT
deposit
§ NEW
high
grade
Proterozoic
metamorphic
terrane
ranked
highly
as
interpreted
NW
extension
of
Broken
Hill
Block
on
craton
margin
§ MagneLc
(short
strike
length
&
‘boat-­‐shaped’
anomalies)
and
gravity
seung
(large
dense)
similar
to
Broken
Hill
&
Cannington
§ Apparent
BHT
‘alteraLon’
/
‘unusual’
lithologies
in
previous
drilling
§ Outcrop
age
equivalent
to
sequence
below
Cannington
&
BH
§ Successful
PACE
Discovery
Drilling
2015
grant
Woodmurra
Project
–
Technical
Summary

18. Reliable
Team
Required

19. BHT
Minerals
Pty
Ltd
was
incorporated
in
2014
to
specifically
explore
for
giant
Broken
Hill-­‐type
(BHT)
base-­‐metal
deposits
within
Australia.
Who
Are
BHT
Minerals?
Dr
Douglas
Haynes
Formally
Chief
Geologist
WMC,
BHP/BHPBilliton.
Key
member
of
discovery
teams
on
Olympic
Dam,
Ernest
Henry,
Kamoa.
Bob
Skrzeczynski
Formally
ExploraLon
Manager
BHP
Cannington
discovery.
Mark
Dugmore
Formally
ExploraLon
Manager
BHP,
Global
Base
Metals.

20. Discovering
the
NEXT
Broken
Hill
Mark
Dugmore
Mobile:
+61
(0)407
132
975
Email:
markdugmore@bigpond.com