Iron ore mining in proximity to a significant Aboriginal heritage rock shelter, Pilbara Region, Western Australia. Brendan Bow Atlas Iron Limited

1. Iron ore mining in proximity to a significant Aboriginal heritage rock
shelter, Pilbara Region, Western Australia.
Brendan Bow
Atlas Iron Limited

2. Overview
Background – Atlas Iron, Traditional Owners, Abydos Iron Ore Project.
Yurlu Kankala cave discovery and its significance.
Scarborough deposit and pit proximity to cave.
Decision to mine.
Detailed Investigations – Aboriginal Heritage and Mining.
Summary.
Conclusion.

3. Acknowledgements
The Turrball People, the original owners and
custodians of the region of present-day Brisbane.
Njamal Traditional Owners, the original owners
and custodians of the region of the Abydos Mine.
Mr Jin Jun Jiang (JJJ), co-author.

4. Atlas Iron Limited
Mid-sized iron-ore miner.
Operations in the northern Pilbara, WA.
Mines closed and undergoing
rehabilitation
- Pardoo, Wodgina and Abydos.
Current operations
- Mt Webber and Mt Dove.
Future projects
- Corunna Downs and McPhee Creek.
Road haulage to port, export via Utah
Point, Port Hedland.

5. Traditional Owners
Mining/Native Title Agreements
- Njamal, Ngarla, Kariyarra and Palyku
Traditional Owners.
Atlas works closely with Traditional
Owners to ensure compliance with
Aboriginal heritage protocols.
Archaeological and Ethnographical
surveys prior to any ground disturbance,
including exploration drilling.

6. Abydos Iron Ore Project
Located 130km south of Port Hedland.
Within the Njamal Native Title Claim.
Exploration drilling commenced in 2008.
Seven iron ore deposits identified.
Mine development commenced in late
2012, mining in June 2013.
Mining completed in September 2017.

7. Discovery of Rock Shelter
2008
- Aboriginal heritage clearance survey for
exploration drill lines and pads.
- Scarborough deposit mineralisation identified.
- No caves recorded.
2012
- Conceptual mine layout developed.
- Cave identified during archaeological and
ethnographic surveys with Traditional Owners.
- Probing of the cave floor suggested earlier
occupation.

8. Discovery of Rock Shelter
April 2013
- Archaeological excavation and salvage to record
the nature and extent of Aboriginal occupation.
- Charcoal sent to University of Adelaide for radio-
carbon dating.
November 2013
- Carbon dating indicated that the cave contained
artefacts significantly older than others in the area.
- Cave registered as a heritage site and protected
under the WA Aboriginal Heritage Act.

9. Significance of Rock Shelter
A large, single chamber cave with two
entrances.
Extends over an area of 60m long by
20m wide.
Occupied from between 44950 –
42760 years ago.
One of the oldest known utilised caves
in the Pilbara.

10. Significance of Rock Shelter
Site is rare – charcoal samples
showed continued human occupation
during the Last Glacial Maximum.
Ranks amongst the most important
sites in Aboriginal archaeological
heritage in Australia.

11. Scarborough Pit
High grade hematite ore.
780kt of high grade ore (57.1% Fe)
Waste: ore strip ratio of 0.66:1.
Pit shell daylights through the ridge,
such that the economic ore can be fully
recovered.

12. Scarborough Pit
The proposed pit was 20m from the cave.
Increasing the cave buffer sterilised
significant ore reserves.
Reducing the Scarborough ore reserve
would have resulted in accelerated and
early mine closure.
Expert global stability assessment
suggested mining was achievable subject
to appropriate controls.

13. Decision to Mine
Commencement of;
- Extensive consultation with Traditional
Owners and Government.
- Approvals under the Aboriginal Heritage
Act.
- Detailed Aboriginal heritage and
geotechnical investigations.
- Multi-disciplinary working group.
Finalisation of environmental approvals.

14. Excavation
Consultation and negotiation with Traditional
Owners.
Approvals under the Aboriginal Heritage Act
obtained for further archaeological excavation.
Extensive excavation with assistance from
University of Western Australia.
Detailed recording and salvage of
archaeological material for further research.
Occupation extended to 46150–42820 years
ago.

15. Approvals
Approvals from Minister for Aboriginal Affairs
subject to commitments in mining application.
Atlas committed to;
- Detailed geotechnical assessment.
- Blasting and vibration model.
- Cave monitoring and inspection plan.
- Risk assessment and Trigger-Action Response
Plan.
- Cultural Heritage Management Plan.
- No impact to the global stability of the cave.

16. Geotechnical Assessment
Development of a global stability model
based on mining within 20m.
Photography and mapping of cave.
Assessment of stress relief induced rock
damage from pit excavation.
Assessment of blasting induced impacts
from rock damage and seismic effects.
Acceptable risk if blasting and vibration
control measures applied.

17. Blasting Control Measures
Reduction of blast depths, benches less than
5m in height.
Reduction of maximum instantaneous
charge including reduced blast hole diameter
and loading.
Delay sequences that promote single hole
firing, thus reducing ground vibrations.
Optimisation of blast design by altering
drilling patterns and blast hole inclination
from the vertical.
Firing to free faces.

18. Blasting and Ground Vibration
Site Vibration Law established.
Seed holes adjacent and within deposit.
Blast simulation modelling.
Charge weights and delay times modelled to
meet ground vibration limits.
Ground vibration measured using two
accelerometer tri-axial arrays.
Continuous calibration and update of ground
vibration model.

19. Cave Monitoring and Inspection
Visual inspections.
Digital photography to provide a
comprehensive and comparative
photographic record.
Laser scan of cave.
Shade cloth ground sheet to assist
identification of any rockfalls.
Vibration monitoring of blast events.

20. Trigger-Action Response Plan
Action and responsibility for mine
operations personnel in response to
deviations in site conditions.
How to respond appropriately to any
observed deviations.
i.e. exceedance of vibration limits.
Any change in condition that may affect
environmental or heritage status
i.e. size or quantity of rockfall.
Trigger Action Response Plan (TARP): Yurlu Kankala Cave - Ground Monitoring Sheet 1 of 1 (original size A3)
Atlas Iron Ltd. - Abydos Project Revision: C (draft for review)
Monitoring objective: Identification and measurement of mechanismsthat control ground behaviour in the vicinity of the Yurlu Kankala cave; visual observations of ground conditions and changes in conditions; measurement of physicalparameters that indicate or respond to mining activities; validation and calibration of stability assessments (includingnumerical modelling) and predictive blast vibration models; and
assistance with risk management.
Monitoring system: Visual observation/inspection; photography to provide comprehensive comparative record of the Yurlu Kankala cave and surrounds; installation of shade cloth ground sheet to assist identification of any falls of ground within the Yurlu Kankala cave; and vibration monitoring of blast events.
Status & Response Level: Condition: Green Condition: Orange Condition: Red Notes
Monitoring: Monitoring Frequency: Alert Thresholds:
Required
Action:
Alert Thresholds: Required Action:
Visual Monitoring Exterior:
Crest of slope above Yurlu Kankala: visual
observation only
Daily during any blasting or excavation within Yurlu Kankalaactive
zone (refer Note 1).
No discerniblechange in ground conditions.
Any observed change in ground conditions or category 2 Rockfall
Event.
A
Any observed change in ground conditions or Category 3
Rockfall Event.
A,B,C
Slope face around Yurlu Kankala: visual
observation only
Weekly during any blasting or excavation within Yurlu Kankala
active zone (refer Note 1).
No discerniblechange in ground conditions.
Any observed change in ground conditions or category 2 Rockfall
Event.
A
Any observed change in ground conditions or Category 3
Rockfall Event.
A,B,C
Slope face around Yurlu Kankala:
photography
Once prior to, and once following, each Scarborough pit or ramp
blast.
No discerniblechange in ground conditions.
Any observed change in ground conditions or category 2 Rockfall
Event.
A
Any observed change in ground conditions or Category 3
Rockfall Event.
A,B,C
Visual inspection - slope below Yurlu Kankala
Weekly during any blasting or excavation within Yurlu Kankala
active zone (refer Note 1).
No discerniblechange in ground conditions.
Any observed change in ground conditions or category 2 Rockfall
Event.
A
Any observed change in ground conditions or Category 3
Rockfall Event.
A,B,C
Visual Monitoring Interior:
Yurlu Kankalainterior: visual observation
Once prior to, and once following, each Scarborough pit or ramp
blast.
No discerniblechange in ground conditions.
Any observed change in ground conditions or Category 1 or 2
Rockfall Event
A, B
Any observed change in ground conditions or Category 3
Rockfall Event.
A,B,C
Yurlu Kankalainterior: photography
Once prior to, and once following, each Scarborough pit or ramp
blast.
No discerniblechange in ground conditions.
Any observed change in ground conditions or Category 1 or 2
Rockfall Event
A, B
Any observed change in ground conditions or Category 3
Rockfall Event.
A,B,C
Yurlu Kankalainterior: observation and
recording of any fallen material on shade
cloth
Once prior to, and once following, each Scarborough pit or ramp
blast.
No fallen material.
Any observed change in ground conditions or Category 1 or 2
Rockfall Event
A, B
Any observed change in ground conditions or Category 3
Rockfall Event.
A,B,C
Blast Monitoring:
Vector Peak Particle Velocity (VPPV) -
monitored using triaxial accelerometers
For each Scarborough pit or ramp blast. VPPV < 40 mm/sec VPPV > 40 mm/sec, < 50 mm/sec D VPPV > 50 mm/sec E
To be reviewed by project team, &
subject to review after each blast
event.
Ground acceleration (a) - monitored using
triaxial accelerometers
For each Scarborough pit or ramp blast. a <0.3 g a > 0.3 g, < 0.4 g D a > 0.4 g E
To be reviewed by project team, &
subject to review after each blast
event.
Roles and Responsibilities Required Actions
Company Person Title Role
Action A:
Inform the Abydos QM, Abydos RM and Atlas PrincipalGeotechnicalEngineer of the event.
A meeting is to be conducted to;
1. Risk assess the impact of the event and implement any additionalcontrols required to;
a). Ensure safety of persons carrying out monitoringactivities and;
b). To reduce further events as far as reasonably practical.
2. Log the event as a hazard in INX with "YKC" at the beginning of the event title and event report subtype "10 Ground Conditions".
3. Mark on the photography where the ground conditionshave changed. Attach marked photo to INX hazard report.
4. Attach any inspection and photographic information to the hazard in INX
5. Suspend all mining activity and restrict access to cave until RM approval has been given to re-commence activities.
Atlas Iron Ltd.
Adam Liebenberg Registered Manager Overall responsibility for Monitoring Plan and its implementation
Adam Martin Alternate Registered Manager Alternate for Registered Manager. Action B.
As for Action A and;
1. Notify the GM Operations as soon as practicable in person or by phone within 12hrs of the event and the COO as soon as practicable but not
exceeding 24hrs.
2. Notify the Manager- Land Access, Heritage and Approvals and the GM Technical Services as soon as practicable within 12hrs of the event.
3. Log the event as an incident in INX with "YKC" at the beginning of the event title and event report subtype "Incident - Geotechnical".
4. Suspend all mining activity and restrict access to cave until GM Operations approval has been given to re-commence activities.
5. Site visit to inspect cave by PrincipalGeotechnicalEngineer Required, external specialist involvement as required.Nigel Dilkes Senior Production Engineer
Responsible for development of 3 month schedules, blasting
designs and collection of monitoring data.
Daniel McKeon Senior Production Engineer
Responsible for development of 3 month schedules, blasting
designs and collection of monitoring data.
Action C:
As for Action A and B and;
1. Notify the COO as soon as practicable not exceeding 2hrs in person or by phone and the MD within 12hrs.
2. Suspend all mining activity and restrict access to cave until COO approval has been given to re-commence activities.
3. External Geotechnicalspecialist to be engaged to inspect the site and provide a written assessment
Peter Dunstan Junior Engineer Weekly plans and blast designs. Collection of monitoring data.
Action D:
As for B and;
1. Formal review of the site vibration law by the Technical Services Team Leader - Iron Ore Pilbara Mining Services is required to calibrate with
blast outcomes.
2. Review of blast design is required to ensure levels are reduced below established limits .
Jin Jun Jiang PrincipalGeotechnicalEngineer All aspects of geotechnical support and advice.
Action E:
As for action C and;
1. Formal review of the site vibration law by the Technical Services Team Leader - Iron Ore Pilbara Mining Services is required to calibrate with
blast outcomes.
2. Review of blast design is required to ensure levels are reduced below established limits .
Sarah Eatough Senior Land Access Advisor
Manage all aspects of land access. External stakeholder liaison.
Assist Land Access, Heritage & Approvals Manager.
Brendan Bow Manager – Land Access, Heritage and Approvals
Key stakeholdermanager and responsible for compliance with
heritage approvals.
Orica Mining Services James Tiedgen
Technical Services Team Leader - Iron Ore Pilbara Mining
Services
External specialist technicaladvisor – blasting. Conduct blast
review and simulation. Calibration of site blasting model.
Coffey International Ltd. Peter Lamb Instrumentation & Monitoring Group Manager
External specialist technicaladvisor – geotechnical, including
instrumentation & monitoring
Notes:
(1) The Yurlu Kankala active zone is defined as the area between 72015mE (i.e. the west end of Scarborough Pit) and 721260mE (i.e. the east end of the Leighton road cut), and between 766100mN and 766200mN.

21. Cultural Heritage Management Plan
Outlines how potential impacts to the Yurlu Kankala cave
from the development and mining of the Scarborough
deposit will be managed;
- Risk Assessment.
- Table of Commitments.
- Monitoring Plan and TARP.
- Communication Plan.
- Access Procedure.
- Blast Procedure.
- Maps.
- Reference List.
The CHMP was approved and signed by the Atlas CEO.

22. Summary - Blasting and mining
Mining successfully completed in September 2017.
99 production blasts (and 4 seed hole test blasts) recorded in the 22 months
of operation.

23. Summary - Rockfall
A total of 343 minor rock falls were
reported.
The majority of the rock falls were from
areas of weathered foliation.
Less than an estimated 0.2% of the cave
roof area affected.

24. Summary - Traditional Owners
The project has delivered Njamal Traditional
Owners;
- Strong sense of pride and reinforced
connection to their country.
- Expanded the groups understanding of
their Njamal identity.
- Significant contribution to Native Title
determination.
- The cave acts as an important focal point
for the transmission of traditional
knowledge and skills.

25. Summary - Community
Significance to broader community;
- Contributes to the research in
understanding the lifeways of Aboriginal
people in the Pilbara past and present.
- Public and media interest in cave has
focused on the archaeological date of
the cave.
- Initiated a number of post-graduate
research projects.

26. Conclusion
- Native Title Agreement obligations exceeded.
- Mining successfully completed.
- The mine is currently in a process of rehabilitation and closure.
- Traditional Owners have requested that access to the cave be restricted.

27. Thank you
Mr Don Miller, Principal Engineering
Geologist.
Mr James Tiedgen, Technical
Service Team Leader - Pilbara