GREAT BOULDER RESOURCES LIMITED — Capital/Financing Update 2019

Mar 4, 2019

More strong metallurgical results from Mt Venn highlight development potential

High-quality copper, nickel and cobalt concentrates produced from the Mt Venn deposit within the Yamarna Project, WA

Highlights

• Latest results demonstrate a robust, reliable flowsheet developed in the preliminary metallurgical program can produce readily marketable copper and nickel-cobalt sulphide concentrates

• The results strengthen the economic potential of Great Boulder’s Yamarna project as they show high-quality sulphide concentrates can be produced from Mt Venn

• High overall copper recovery of more than 90% achieved in the flotation and leach circuit to produce a +20% saleable copper sulphide concentrate

• Exceptionally high-value nickel-cobalt sulphide concentrate produced grading 26% Ni and 9% Co, suitable for use in the battery and EV markets

• Overall nickel and cobalt recoveries approaching 80% in a combined nickelcobalt sulphide product demonstrated in these initial trials

• Improved nickel and cobalt recoveries expected from higher-grade and highertenor mineralisation at the Eastern Mafic and Winchester (drilling underway)

Great Boulder Resources (ASX:GBR) is pleased to announce more strong results from initial metallurgical testwork completed on samples from the Mt Venn deposit, within the Company’s Yamarna project in Western Australia.

The testwork was completed on a composite diamond drill hole sample from Mt Venn containing copper mainly as chalcopyrite, and nickel and cobalt in solid solution in pyrrhotite.

The primary purpose of the testwork was to demonstrate a viable flowsheet that would maximize recovery for multiple, high-value products containing copper, nickel and cobalt.

Copper is recovered primarily through a conventional flotation circuit to produce a copper concentrate, with nickel and cobalt recovery from a separate bulk concentrate through a hydrometallurgical circuit to produce a high purity nickel-cobalt sulphide concentrate.

The leaching circuit recovered over 90% of nickel and cobalt from pyrrhotite and also captured the majority of copper rejected from the floatation circuit, producing a high purity (46% Cu) sulphide that when combined with the flotation concentrate, improves overall copper recovery to above 90%.

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The testwork was completed on a relatively low-grade sample, containing 0.43% Cu, 0.18% Ni and 0.06% Co. Recent drilling at the Eastern Mafic and Winchester has identified significantly higher grade and tenor nickel sulphide that is expected to improve recoveries through the flotation and leach circuits.

Great Boulder Managing Director Stefan Murphy said the results exceeded expectations and a clear development path had been set for the Yamarna project.

“These results show that high-quality concentrates can be produced at high recoveries from sulphide mineralisation at Mt Venn,” Mr Murphy said.

“Our preference to pursue a combined nickel-cobalt sulphide concentrate has demonstrated an exceptional high value product can be produced, with scope to further improve concentrate grade through process optimization.

“These results are based on early drilling from Mt Venn before the Eastern Mafic was discovered and we are confident that the higher nickel grades we are seeing at the Eastern Mafic and nearby Winchester deposits will further improve overall recoveries.”

Metallurgical Testwork Summary

Initial metallurgical testwork has been completed on a composite diamond drill hole sample from Mt Venn

The key objective of this phase of metallurgical testwork is to develop a robust, viable flowsheet for Mt Venn.

Testwork was completed to:

• Test the ability to separate copper into a saleable concentrate, with minimal losses of other value metals

• Select leaching conditions for nickel and cobalt extraction from bulk pyrrhotite concentrate

• Demonstrate effective impurity rejection

• Select the preferred route for nickel and cobalt recovery that would be relatively simple and generate high value products

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Figure 1 . Simplified process flowsheet

Flotation testwork was conducted on the Mt Venn Composite sample to produce a separate

• Copper concentrate (chalcopyrite), and

• Bulk nickel-cobalt-copper concentrate (pyrrhotite +/- chalcopyrite)

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A clean copper flotation concentrate with no deleterious elements was produced in the flotation circuit grading between 16 and 20% Cu. This flotation concentrate is mixed with the high purity copper sulphide (46% Cu) produced from the hydrometallurgical circuit to generate a combined saleable +20% Cu concentrate at over 90% overall recovery.

~90% of both nickel and cobalt was recovered into a bulk concentrate following copper flotation. The nickel and cobalt upgrade into the bulk concentrate is modest (~70%) to 0.31% Ni and 0.10% Co, which reflects the tenor of metal in sulphide.

Drilling at the Eastern Mafic and Winchester projects has returned considerably higher nickel tenor of 1-3% Ni which should positively influence the future nickel and cobalt upgrade to the hydrometallurgy circuit and recoveries.

The bulk concentrate underwent leaching and solution purification testing to produce high value sulphide products that are in demand in the battery and EV markets. Two leaching processes were investigated:

• Atmospheric oxidative leach, and

• Pressure oxidation (POX).

While atmospheric leach tests indicated good metal recoveries of over 85%, POX process was selected in this phase of work due to higher recoveries and improved quality of leach solution for downstream processing.

Successful tests were carried out at 1,000 kPa oxygen pressure and 150°C temperature, with almost complete extractions of value metals typically achieved within 60-90 minutes. Average extractions of 92%, 97% and 96% were achieved for nickel, cobalt and copper respectively.

The selected POX leach conditions are less costly and energy intensive than those used for High Pressure Acid Leach (“HPAL”) of nickel laterites that typically operate at very high pressure (~4,500 kPa) and temperature (~250°C) and require significant acid addition.

Following POX, the leached slurry is neutralised with limestone to remove residual acid and the majority of iron from solution.

Minor losses of copper occur at this stage but most of the nickel and cobalt metal is retained in solution (>95%). As the subsequent nickel and cobalt recovery by sulphide precipitation is not sensitive to iron concentration at low levels, metal losses in neutralisation can be further reduced by targeting a lower terminal pH through reduced limestone addition.

Precipitation testwork on neutralised liquor successfully produced very high-quality copper sulphide and a combined nickel and cobalt sulphide product with no deleterious elements and at very high extraction rates of 95-99%.

Precipitation testwork on neutralised liquor successfully produced very high-quality copper sulphide and a combined nickel and cobalt sulphide product with no deleterious elements and at very high extraction rates of 95-99%.	Precipitation testwork on neutralised liquor successfully produced very high-quality copper sulphide and a combined nickel and cobalt sulphide product with no deleterious elements and at very high extraction rates of 95-99%.	Precipitation testwork on neutralised liquor successfully produced very high-quality copper sulphide and a combined nickel and cobalt sulphide product with no deleterious elements and at very high extraction rates of 95-99%.	Precipitation testwork on neutralised liquor successfully produced very high-quality copper sulphide and a combined nickel and cobalt sulphide product with no deleterious elements and at very high extraction rates of 95-99%.	Precipitation testwork on neutralised liquor successfully produced very high-quality copper sulphide and a combined nickel and cobalt sulphide product with no deleterious elements and at very high extraction rates of 95-99%.	Precipitation testwork on neutralised liquor successfully produced very high-quality copper sulphide and a combined nickel and cobalt sulphide product with no deleterious elements and at very high extraction rates of 95-99%.	Precipitation testwork on neutralised liquor successfully produced very high-quality copper sulphide and a combined nickel and cobalt sulphide product with no deleterious elements and at very high extraction rates of 95-99%.	Precipitation testwork on neutralised liquor successfully produced very high-quality copper sulphide and a combined nickel and cobalt sulphide product with no deleterious elements and at very high extraction rates of 95-99%.
SUMMARY OF RESULTS: PRECIPITATE ASSAYS
	Assay (%)
Product	Cu	Ni	Co	Fe	Al	Ca	Mg
Copper sulphide	45.9	2.85	1.28	0.30	0.20	2.10	0.36
Mixed sulphide	0.81	25.9	9.22	1.49	0.29	0.22	0.31

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The copper sulphide product is extremely high-grade and free of any deleterious elements. It is added back into the copper flotation concentrate to produce an attractive +20% copper concentrate at a high overall recovery of over 90%.

The mixed nickel-cobalt concentrate is a high-grade and very high value intermediate product (+35% Ni+Co) suitable for the battery and EV markets.

Overall recoveries of ~80% for Ni and Co are impacted by the low nickel and cobalt tenor of the selected Mt Venn material used in this preliminary testwork. Sulphide mineralisation at the Eastern Mafic and Winchester both exhibit significantly higher nickel tenor and are expected to materially improve overall recoveries.

Solvent extraction (“SX”) and crystallisation testwork has also been successfully completed to produce a very high purity cobalt sulphate product grading 29% Co or +99% Cobalt sulphate (see below product specifications).

The particularly high-grade and purity cobalt sulphate is a premium refined product in demand for use in the battery and EV markets.

Additional nickel sulphide precipitation testwork was conducted on cobalt free liquor post cobalt removal by SX. A very high purity nickel sulphide concentrate grading 41% Ni and 1.5% Co was produced (see below product specifications).

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Figure 2 . Cobalt Sulphate crystals produced from SX and crystallisation testwork

SUMMARY OF RESULTS: CRYSTAL ASSAYS	SUMMARY OF RESULTS: CRYSTAL ASSAYS	SUMMARY OF RESULTS: CRYSTAL ASSAYS	SUMMARY OF RESULTS: CRYSTAL ASSAYS	SUMMARY OF RESULTS: CRYSTAL ASSAYS	SUMMARY OF RESULTS: CRYSTAL ASSAYS	SUMMARY OF RESULTS: CRYSTAL ASSAYS	SUMMARY OF RESULTS: CRYSTAL ASSAYS
Product	Assay (%)
	Al	Ca	Co	Cu	Fe	Mg	Ni
Cobalt sulphate	0.25	0.00	28.9	0.00	0.06	0.74	0.02

SUMMARY OF RESULTS: PRECIPITATE ASSAYS	SUMMARY OF RESULTS: PRECIPITATE ASSAYS	SUMMARY OF RESULTS: PRECIPITATE ASSAYS	SUMMARY OF RESULTS: PRECIPITATE ASSAYS	SUMMARY OF RESULTS: PRECIPITATE ASSAYS	SUMMARY OF RESULTS: PRECIPITATE ASSAYS	SUMMARY OF RESULTS: PRECIPITATE ASSAYS	SUMMARY OF RESULTS: PRECIPITATE ASSAYS
Product	Assay (%)
	Ni	Co	Cu	Ca	Fe	Mg	Al
Nickel sulphide	40.9	1.49	0.0	0.60	0.08	0.22	0.08

While the testwork to produce a high-value and readily saleable cobalt sulphate product was successful, the solvent extraction circuit and additional solution purification requirements add significant cost and technical risk to the process flowsheet.

It was decided at this stage of testwork to focus on a simplified precipitation flowsheet, producing copper and nickel-cobalt sulphide concentrates.

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The significantly larger, well established markets and ability to freely trade and hedge copper and nickel-cobalt sulphide concentrates makes this an attractive process route.

The reduced capital and operating costs, as well as transport, logistics and marketing benefits in a more transparent market are all important considerations when deciding the optimal process flowsheet for future metallurgical testwork.

The next steps will be to collect diamond drill core from the Eastern Mafic during this current drilling campaign and conduct metallurgical testwork using similar but more optimised conditions than the initial Mt Venn testwork.

Once the formal joint venture agreement is in place for Winchester, further drilling will be completed to define the mineralised lenses and collect representative samples for additional metallurgical testwork.

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Winchester
Yamarna
Mt Carlon
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Figure 3 . Project Location Map

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Competent Person’s Statement

Exploration information in this Announcement is based upon work undertaken by Mr Stefan Murphy whom is a Member of the Australasian Institute of Geoscientists (AIG). Mr Stefan Murphy has sufficient experience that is relevant to the style of mineralisation and type of deposit under consideration and to the activity which he is undertaking to qualify as a ‘Competent Person’ as defined in the 2012 Edition of the ‘Australasian Code for Reporting of Exploration Results, Mineral Resources and Ore Reserves’ (JORC Code). Mr Stefan Murphy is an employee of Great Boulder and consents to the inclusion in the report of the matters based on their information in the form and context in which it appears.

Forward Looking Statements

This Announcement is provided on the basis that neither the Company nor its representatives make any warranty (express or implied) as to the accuracy, reliability, relevance or completeness of the material contained in the Announcement and nothing contained in the Announcement is, or may be relied upon as a promise, representation or warranty, whether as to the past or the future. The Company hereby excludes all warranties that can be excluded by law. The Announcement contains material which is predictive in nature and may be affected by inaccurate assumptions or by known and unknown risks and uncertainties and may differ materially from results ultimately achieved.

The Announcement contains “forward-looking statements”. All statements other than those of historical facts included in the Announcement are forward-looking statements including estimates of Mineral Resources. However, forward-looking statements are subject to risks, uncertainties and other factors, which could cause actual results to differ materially from future results expressed, projected or implied by such forward-looking statements. Such risks include, but are not limited to, copper, gold and other metals price volatility, currency fluctuations, increased production costs and variances in ore grade recovery rates from those assumed in mining plans, as well as political and operational risks and governmental regulation and judicial outcomes. The Company does not undertake any obligation to release publicly any revisions to any “forward-looking statement” to reflect events or circumstances after the date of the Announcement, or to reflect the occurrence of unanticipated events, except as may be required under applicable securities laws. All persons should consider seeking appropriate professional advice in reviewing the Announcement and all other information with respect to the Company and evaluating the business, financial performance and operations of the Company. Neither the provision of the Announcement nor any information contained in the Announcement or subsequently communicated to any person in connection with the Announcement is, or should be taken as, constituting the giving of investment advice to any person.

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Appendix 1 –Drill hole 17MVDD002 Significant Intersections

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17MVDD002
Cu % Ni % Co ppm
From To Interval
(max graph 2%) (max graph 0.3 %) (max graph 1000ppm)
8 9 1 0.37 0.04 141
9 10 1 0.50 0.03 188
10 11 1 0.45 0.05 229
11 12.3 1.3 0.27 0.07 327
12.3 13 0.7 0.76 0.08 323
13 14 1 0.89 0.16 587
14 15 1 0.38 0.24 867
15 15.75 0.75 0.60 0.24 831
15.8 16.3 0.55 0.22 0.04 89
16.3 17 0.7 0.43 0.07 281
17 18 1 1.51 0.05 213
18 19 1 0.38 0.15 537
19 20 1 0.55 0.11 421
20 21 1 0.85 0.13 483
21 22 1 0.43 0.23 798
22 23 1 0.26 0.24 823
23 24 1 0.72 0.26 890
24 25 1 0.37 0.28 964
25 26 1 0.30 0.22 755
26 27 1 0.30 0.18 611
27 28 1 0.40 0.13 458
28 29 1 0.50 0.16 551
29 30 1 0.41 0.15 531
30 31 1 1.39 0.11 396
31 32 1 0.22 0.24 804
32 33 1 0.28 0.26 866
33 34 1 0.19 0.26 857
34 35 1 0.56 0.17 577
35 36 1 0.43 0.16 548
36 37 1 0.54 0.11 358
37 38 1 0.35 0.21 671
38 38.5 0.5 0.41 0.19 617
47 48 1 0.61 0.08 343
48 49 1 1.74 0.06 184
49 50 1 0.19 0.20 569
50 51 1 0.81 0.03 108
51 52 1 0.23 0.17 538
52 52.65 0.65 0.67 0.04 126
52.7 53.4 0.75 0.06 0.26 758
53.4 54.1 0.7 1.46 0.15 460
54.1 55 0.9 0.20 0.25 739
55 56 1 0.39 0.24 707
56 57 1 0.31 0.24 699
57 58 1 0.28 0.20 606
58 59 1 0.16 0.24 714
59 60 1 0.18 0.25 757
60 60.9 0.9 0.18 0.24 734
60.9 61.9 1 0.30 0.05 162
61.9 62.9 1 0.08 0.10 306
62.9 63.9 1 0.26 0.01 29
63.9 64.3 0.4 1.37 0.04 154
64.3 65 0.7 0.53 0.17 499
65 66 1 0.24 0.22 667
66 66.6 0.6 0.12 0.24 716
66.6 67 0.4 1.08 0.12 380
67 68 1 0.11 0.18 554
68 68.5 0.5 0.73 0.15 469
68.5 69 0.5 0.12 0.22 652
69 70 1 0.20 0.18 561
70 71 1 0.19 0.18 546
71 71.38 0.38 0.11 0.21 664
71.4 72.18 0.8 0.80 0.08 257
72.2 73 0.82 0.14 0.01 49
83.8 84.2 0.38 0.36 0.02 57
84.2 85 0.8 0.41 0.18 567
85 86 1 0.11 0.24 735
86 87 1 0.31 0.20 621
87 87.68 0.68 0.70 0.15 485
98 99 1 0.61 0.06 189
107 108 0.7 0.07 0.21 616
108 108.5 0.5 0.29 0.18 513
109 108.8 0.3 0.21 0.04 132
109 109.2 0.4 1.12 0.06 178
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JORC Code, 2012 Edition Table 1

The following table relates to activities undertaken at Great Boulder’s Yamarna project.

Section 1 Sampling Techniques and Data

(Criteria in this section apply to all succeeding sections.)

Criteria	JORC Code explanation	JORC Code explanation	Commentary
Sampling	•	Nature and quality of sampling (eg cut	This announcement reports metallurgical test work on
techniques		channels, random chips, or specific	diamond drill hole 17MVDD002 from the Company’s Mt
		specialised industry standard measurement	Venn project.
		tools appropriate to the minerals under
		investigation, such as down hole gamma	Drill hole and assay data for 17MVDD002 has previously
		sondes, or handheld XRF instruments, etc).	been reported to the ASX on 14 February 2018.
		These examples should not be taken as
		limiting the broad meaning of sampling.	Samples were chosen from mineralised zones determined
			by assay results, obtained from ALS Minerals (Perth).
	•	Include reference to measures taken to
		ensure sample representivity and the	Sample intervals of the mineralised zone was undertaken,
		appropriate calibration of any	based on the guidance above.
		measurement tools or systems used.
	•	Aspects of the determination of
		mineralisation that are Material to the
		Public Report.
	•	In cases where ‘industry standard’ work has
		been done this would be relatively simple
		(eg ‘reverse circulation drilling was used to
		obtain 1 m samples from which 3 kg was
		pulverised to produce a 30 g charge for fire
		assay’). In other cases more explanation
		may be required, such as where there is
		coarse gold that has inherent sampling
		problems. Unusual commodities or
		mineralisation types (eg submarine
		nodules) may warrant disclosure of detailed
		information.
Drilling	•	Drill type (eg core, reverse circulation, open-	See ASX Announcement on 14 February 2018
techniques		hole hammer, rotary air blast, auger,
		Bangka, sonic, etc) and details (eg core
		diameter, triple or standard tube, depth of
		diamond tails, face-sampling bit or other
		type, whether core is oriented and if so, by
		what method, etc).
Drill sample	•	Method of recording and assessing core and	Recovery on 17MVDD002, selected for metallurgical test
recovery		chip sample recoveries and results assessed.	work, was good.
	•	Measures taken to maximise sample
		recovery and ensure representative nature
		of the samples.
	•	Whether a relationship exists between
		sample recovery and grade and whether
		sample bias may have occurred due to

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		preferential loss/gain of fine/coarse
		material.
Logging	•	Whether core and chip samples have been	See ASX Announcement on 14 February 2018
		geologically and geotechnically logged to a
		level of detail to support appropriate
		Mineral Resource estimation, mining
		studies and metallurgical studies.
	•	Whether logging is qualitative or
		quantitative in nature. Core (or costean,
		channel, etc) photography.
	•	The total length and percentage of the
		relevant intersections logged.
Sub-sampling	•	If core, whether cut or sawn and whether	Diamond Core was cut using a core saw. ¾ core was
techniques		quarter, half or all core taken.	submitted to the laboratory for metallurgical test work
and sample
preparation	•	If non-core, whether riffled, tube sampled,	Samples for metallurgical testing were assayed before
		rotary split, etc and whether sampled wet or	commencement of metallurgical test work, to ensure
		dry.	appropriate material was sampled.
	•	For all sample types, the nature, quality and	A total of 430.5 kg of core was collected from
		appropriateness of the sample preparation	17MVDD002 for metallurgical test work.
		technique.
	•	Quality control procedures adopted for all sub-sampling stages to maximise representivity of samples.	Two 16 kg subsamples of the composite were used in the flotation circuit to make approximately 2.3 kg of Copper rougher concentrate and approximately 16 kg of a bulk nickel-cobalt pyrrhotite concentrate.
	•	Measures taken to ensure that the sampling
		is representative of the in situ material	Cleaner flotation tests were completed on the copper
		collected, including for instance results for	rougher concentrate, adjusting for reagent addition,
		field duplicate/second-half sampling.	regrind and a magnetic separation of the pyrrhotite. The
			best results were obtained using the removal of magnetic
	•	Whether sample sizes are appropriate to	pyrrhotite on a P8075μm copper rougher concentrate
		the grain size of the material being sampled.	prior to the copper cleaner stage
			The bulk nickel-cobalt pyrrhotite concentrate and some
			unseparated chalcopyrite was used for leaching testwork.
			The bulk concentrate was reground to P8020 µm and
			transferred into a 1-gallon autoclave, where it was mixed
			with site water to form a slurry.
			Solutions produced from the autoclave tests were
			assayed and subsequent sulphide precipitation tests were
			performed on a synthetic solution made to represent
			different stages of the metal purification process
Quality of	•	The nature, quality and appropriateness of	The samples for metallurgical test work were shipped to
assay data		the assaying and laboratory procedures	ALS Metallurgy, Balcatta. They were assayed individually,
and		used and whether the technique is	and as a composite, prior to commencement of
laboratory		considered partial or total.	metallurgical test work.
tests
	•	For geophysical tools, spectrometers,	ALS Metallurgy also completed assays on the products
		handheld XRF instruments, etc, the	generated from metallurgical test work.

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parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc. • Nature of quality control procedures adopted (eg standards, blanks, duplicates, external laboratory checks) and whether acceptable levels of accuracy (ie lack of bias) and precision have been established.	▪ General base metals and major oxide elements: XRF ▪ Multi-element scans: 4-acid digest/ICP-OES, ICP-MS ▪ Non-sulphide nickel: HClO4/HF digest/AAS ▪ Gold: Fire Assay ▪ Total and Sulphide Sulphur: CS2000 analyses No mineralogy has yet been undertaken on the solid products from the hydrometallurgical process.
Verification of sampling and assaying • The verification of significant intersections by either independent or alternative company personnel. • The use of twinned holes. • Documentation of primary data, data entry procedures, data verification, data storage (physical and electronic) protocols. • Discuss any adjustment to assay data.	The samples for metallurgical test work are from diamond drill hole 17MVDD002 that twinned an earlier RC hole. Mineralised zones reported in assays correspond well with the same zones from the RC twin hole. Great Boulder has strict procedures for data capture, flow and data storage, and validation.
Location of data points • Accuracy and quality of surveys used to locate drill holes (collar and down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation. • Specification of the grid system used. • Quality and adequacy of topographic control.	The hole has been surveyed using Differential GPS (DGPS).
Data spacing and distribution • Data spacing for reporting of Exploration Results. • Whether the data spacing and distribution is sufficient to establish the degree of geological and grade continuity appropriate for the Mineral Resource and Ore Reserve estimation procedure(s) and classifications applied. • Whether sample compositing has been applied.	Composite sample intervals used for metallurgical test work are below, Hole ID From (m) To (m) Wt. (kg) 17MVDD002 12.3 38.5 212.5 17MVDD002 47.0 60.9 114.0 17MVDD002 63.9 72.2 60.5 17MVDD002 84.2 87.7 30.0 17MVDD002 107.3 109.2 13.5 Total 430.5
	Hole ID From (m) To (m) Wt. (kg)
	17MVDD002 12.3 38.5 212.5
	17MVDD002 47.0 60.9 114.0
	17MVDD002 63.9 72.2 60.5
	17MVDD002 84.2 87.7 30.0
	17MVDD002 107.3 109.2 13.5
	Total 430.5
Orientation of data in relation to geological structure • Whether the orientation of sampling achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type. • If the relationship between the drilling orientation and the orientation of key	See ASX Announcement on 14 February 2018

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		mineralised structures is considered to have
		introduced a sampling bias, this should be
		assessed and reported if material.
Sample	•	The measures taken to ensure sample	Great Boulder has strict chain of custody procedures that
security		security.	are adhered to for drill samples.
			The sample for metallurgical test work were prepared for
			dispatch to ALS Metallurgy by senior Great Boulder staff.
Audits or	•	The results of any audits or reviews of	None completed.
reviews		sampling techniques and data.

Section 2 Reporting of Exploration Results

(Criteria listed in the preceding section also apply to this section.)

Criteria	JORC	Code explanation				Commentary
Mineral	•	Type, reference name/number, location				Great Boulder Resource Ltd (GBR) is comprised of several
tenement and		and ownership including agreements or				projects with associated tenements;
land tenure		material issues with	third parties such as
status		joint ventures, partnerships, overriding				Yamarna tenements and details;
		royalties, native title interests, historical
		sites, wilderness or national park and				Exploration licences E38/2685, E38/2952, E38/2953,
		environmental settings.				E38/5957, E38/2958, E38/2320 and prospecting licence
						P38/4178 where,
	•	The security of the tenure held at the
		time of reporting along with any known				GBR holds a 75% interest in the Yamarna Project with its
		impediments to obtaining a license			to	joint venture partner EGMC holding a 25% interest.
		operate in the area.				EGMC has elected to contribute to expenditure to
						maintain its 25% interest I the Yamarna project. If EGMC
						elects to not contribute to the joint venture it will convert
						to a 2% Net Smelter Royalty (NSR) and GBR will have a
						100% interest in the project.
Exploration	•	Acknowledgment	and	appraisal	of	Previous explorers included:
done by other		exploration by other	parties.			− 1990’s. Kilkenny Gold NL completed wide-
parties						spaced, shallow, RAB drilling over a limited
						area. Gold assay only.
						− 2008. Elecktra Mines Ltd (now Gold Road
						Resources Ltd) completed two shallow RC
						holes targeting extension to Mt Venn igneous
						complex. XRF analysis only, no geochemical
						analysis completed.
						− 2011. Crusader Resources Ltd completed
						broad-spaced aircore drilling targeting
						extensions to Thatcher’s Soak uranium
						mineralisation. XRF anlaysis only, no
						geochemical analysis completed.
						− In late 2015 Gold Road drilled and assayed an
						RC drill hole on the edge of an EM anomaly
						identified from an airborne XTEM survey,
						identifying copper-nickel-cobalt mineralisation.

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Geology	•	Deposit type, geological setting and style	Great Boulder’s Yamarna Project hosts the southern
		of mineralisation.	extension of the Mt Venn igneous complex. This complex
			is immediately west of the Yamarna greenstone belt.
			The mineralisation encountered in the Mt Venn drilling
			suggests that sulphide mineralisation is prominent along
			an EM conductor trend, and shows a highly sulphur-
			saturated system within metamorphosed pyroxenite and
			gabbro sequence.
			Visual logging and QEMScan analysis of sulphide
			mineralogy shows pyrrhotite dominant with secondary
			chalcopyrite.
Drill hole	•	A summary of all information material to	See ASX Announcement on 14 February 2018
Information		the understanding of the exploration
		results including a tabulation of the
		following information for all Material drill
		holes:
	o	easting and northing of the drill hole
		collar
	o	elevation or RL (Reduced Level – elevation
		above sea level in metres) of the drill hole
		collar
	o	dip and azimuth of the hole
	o	down hole length and interception depth
	o	hole length.
	•	If the exclusion of this information is
		justified on the basis that the information
		is not Material and this exclusion does not
		detract from the understanding of the
		report, the Competent Person should
		clearly explain why this is the case.
Data	•	In reporting Exploration Results,	No data aggregation was undertaken.
aggregation		weighting averaging techniques,
methods		maximum and/or minimum grade	All results reported are assays on the composite feed
		truncations (eg cutting of high grades)	sample for metallurgical test work, and then assays on the
		and cut-off grades are usually Material	products after the hydrometallurgical tests.
		and should be stated.
	•	Where aggregate intercepts incorporate
		short lengths of high grade results and
		longer lengths of low grade results, the
		procedure used for such aggregation
		should be stated and some typical
		examples of such aggregations should be
		shown in detail.
	•	The assumptions used for any reporting
		of metal equivalent values should be
		clearly stated.
Relationship	•	These relationships are particularly	Samples discussed in this announcement relate to
between		important in the reporting of Exploration	metallurgical test work.
mineralisation		Results.
widths and

ASX Announcement

13

5 March, 2019

==> picture [48 x 57] intentionally omitted <==

==> picture [48 x 57] intentionally omitted <==

intercept	•	If the geometry of the mineralisation with
lengths		respect to the drill hole angle is known, its
		nature should be reported.
	•	If it is not known and only the down hole
		lengths are reported, there should be a
		clear statement to this effect (eg ‘down
		hole length, true width not known’).
Diagrams	•	Appropriate maps and sections (with	See ASX Announcement on 14 February 2018
		scales) and tabulations of intercepts
		should be included for any significant
		discovery being reported These should
		include, but not be limited to a plan view
		of drill hole collar locations and
		appropriate sectional views.
Balanced	•	Where comprehensive reporting of all	Metallurgical test work samples only in this release. For
reporting		Exploration Results is not practicable,	other results, see ASX Announcement on 14 February
		representative reporting of both low and	2018
		high grades and/or widths should be
		practiced to avoid misleading reporting of
		Exploration Results.
Other	•	Other exploration data, if meaningful and	See ASX Announcement on 14 February 2018
substantive		material, should be reported including
exploration		(but not limited to): geological
data		observations; geophysical survey results;
		geochemical survey results; bulk samples
		– size and method of treatment;
		metallurgical test results; bulk density,
		groundwater, geotechnical and rock
		characteristics; potential deleterious or
		contaminating substances.
Further work	•	The nature and scale of planned further	Further metallurgical results will be conducted as part of
		work (eg tests for lateral extensions or	ongoing testwork and studies.
		depth extensions or large-scale step-out
		drilling).
	•	Diagrams clearly highlighting the areas of
		possible extensions, including the main
		geological interpretations and future
		drilling areas, provided this information is
		not commercially sensitive.