DUKETON MINING LIMITED — Interim / Quarterly Report 2021

Oct 26, 2021

27[th] October 2021

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ASX Announcement

Addendum to September 2021 Quarterly Report

Duketon Mining Ltd (DKM) provides the attached amended and re-stated JORC Table 1 (Sections 1 and 2) intended to accompany the ASX Release of today, 27[th] October 2021 “September 2021 Quarterly Report”.

This addendum includes additional technical detail following consultation with ASX.

Authorised for release by:

Stuart Fogarty Duketon Mining Limited - Managing Director

+61 8 6315 1490

Duketon Mining Limited ACN 159 084 107 25 Richardson Street West Perth WA 6005 T: +61 473 798 006

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JORC Table 1

JORC Code, 2012 Edition – Table 1 report – Duketon Project

Section 1 Sampling Techniques and Data – Rosie DHEM Geophysics

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

Criteria	JORC Code explanation	Commentary
Sampling	• Nature and quality of sampling (eg cut channels, random chips, or	•DHEM survey was conducted using the DigiAtlantis system and
techniques	specific specialised industry standard measurement tools appropriate	HP100 transmitter. The readings were recorded at 2.5 to 20m
	to the minerals under investigation, such as down hole gamma	intervals. The survey used a 460m x 500m loop.
	sondes, or handheld XRF instruments, etc). These examples should
	not be taken as limiting the broad meaning of sampling.
	• Include reference to measures taken to ensure sample representivity
	and the appropriate calibration of any 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-hole hammer, rotary air	•N/A – geophysical data only
techniques	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 chip sample recoveries	•N/A – geophysical data only
recovery	and results assessed.
	• Measures taken to maximise sample recovery and ensure
	representative nature of the samples.
	• Whether a relationship exists between sample recovery andgrade

Duketon Mining Limited ACN 159 084 107 25 Richardson Street West Perth WA 6005 T: +61 473 798 006

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Criteria	JORC Code explanation	Commentary	Commentary
	and whether sample bias may have occurred due to preferential
	loss/gain of fine/coarse material.
Logging	• Whether core and chip samples have been geologically and	•	N/A – geophysical data only
	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-	• If core, whether cut or sawn and whether quarter, half or all core	•	N/A – geophysical data only
sampling	taken.
techniques	• If non-core, whether riffled, tube sampled, rotary split, etc and
and sample	whether sampled wet or dry.
preparation	• For all sample types, the nature, quality and appropriateness of the
	sample preparation technique.
	• Quality control procedures adopted for all sub-sampling stages to
	maximise representivity of samples.
	• Measures taken to ensure that the sampling is representative of the in
	situ material collected, including for instance results for field
	duplicate/second-half sampling.
	• Whether sample sizes are appropriate to the grain size of the material
	being sampled.
Quality of	• The nature, quality and appropriateness of the assaying and	•DHEM parameters are as follows:
assay data and laboratory tests	laboratory procedures used and whether the technique is considered partial or total. • For geophysical tools, spectrometers, handheld XRF instruments, etc, the parameters used in determining the analysis including instrument make and model, reading times, calibrations factors applied and their derivation, etc.	• • • • •	Tx Loop Size:460m X 500m Transmitter: HP 100 Receiver: SmartEM Probe: DigiAtlantis Station Spacing: 2.5m to 20m
	• Nature of quality control procedures adopted (eg standards, blanks,	•	Tx Current: 100A
	duplicates, external laboratory checks) and whether acceptable levels	•	Base Frequency: 0.5 and 1Hz
	of accuracy (ie lack of bias) andprecision have been established.	•	Readings: Min 2 repeatable readingsper station

Duketon Mining Limited ACN 159 084 107 25 Richardson Street West Perth WA 6005 T: +61 473 798 006

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Criteria	JORC Code explanation	Commentary	Commentary
		•	Stacks: 64
Verification	• The verification of significant intersections by either independent or	•N/A – geophysical data only
of sampling	alternative company personnel.
and	• The use of twinned holes.
assaying	• Documentation of primary data, data entry procedures, data
	verification, data storage (physical and electronic) protocols.
	• Discuss any adjustment to assay data.
Location of	• Accuracy and quality of surveys used to locate drill holes (collar and	•The grid system used is GDA94, MGA Zone 51
data points	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.
Data spacing	• Data spacing for reporting of Exploration Results.	•N/A – geophysical data only
and	• Whether the data spacing and distribution is sufficient to establish the
distribution	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. _
Orientation	• Whether the orientation of sampling achieves unbiased sampling of	•The orientation of the geology and mineralization at Rosie is steeply
of data in	possible structures and the extent to which this is known, considering	dipping to the south to south-west and striking NNW to W.
relation to	the deposit type.
eological	• If the relationship between the drilling orientation and the orientation
structure	of key 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 security.	•N/A – geophysical data only
security
Audits or	• The results of any audits or reviews of sampling techniques and data.	•No external audits or reviews have been conducted apart from
reviews		internal company review.

Duketon Mining Limited ACN 159 084 107 25 Richardson Street West Perth WA 6005 T: +61 473 798 006

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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 and ownership including	•The tenement (M38/1252) is 100% owned by Duketon Mining Limited
tenement	agreements or material issues with third parties such as joint	and is in good standing and there are no known impediments to
and land	ventures, partnerships, overriding royalties, native title interests,	obtaining a licence to operate in the area.
tenure status	historical sites, wilderness or national park and environmental
	settings.
	• The security of the tenure held at the time of reporting along with any
	known impediments to obtaining a licence to operate in the area.
Exploration	• Acknowledgment and appraisal of exploration by other parties.	•Previous drilling at The Bulge Complex was completed by
done by		Independence Group (IGO) and South Boulder Mines Ltd. This work
other parties		has been checked for quality as far as possible and formed the basis
		of the follow-up conducted as part of the drilling programme
		presented.
Geology	• Deposit type, geological setting and style of mineralisation.	•The Rosie Nickel Deposit is a komatiite-hosted nickel sulphide
		deposit. The mineralisation is characterised by accumulations of
		massive, matrix, breccia and disseminated sulphides at the basal
		contact overlying a basalt footwall.
Drill hole	• A summary of all information material to the understanding of the	•N/A – geophysical data only. All relevant drillhole information
Information	exploration results including a tabulation of the following information	contained within Appendix 2.
	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.

Duketon Mining Limited ACN 159 084 107 25 Richardson Street West Perth WA 6005 T: +61 473 798 006

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Criteria	JORC Code explanation	Commentary
Data	• In reporting Exploration Results, weighting averaging techniques,	•NiEq has been calculated with the following prices (US $) and
aggregation	maximum and/or minimum grade truncations (eg cutting of high	recoveries for Pentlandite (P) and Violarite (V):
methods	grades) and cut-off grades are usually Material and should be stated.	• Ni $8.00/lb., P = 96.9%, V = 88.7%
	• Where aggregate intercepts incorporate short lengths of high grade	• Cu $3.65/lb., P = 99.5%, V = 94.5%
	results and longer lengths of low grade results, the procedure used	• Co $15.30/lb., P = 95.1%, V = 88.5%
	for such aggregation should be stated and some typical examples of	• Pt $1,100/oz., P = 78.2%, V = 57.6%
	such aggregations should be shown in detail.	• Pd $2,300/oz., P = 97.6%, V = 87.3%
	• The assumptions used for any reporting of metal equivalent values	• Rh $15,500/oz., P = 83.4%, V = 64.8%
	should be clearly stated.	•The calculation for the pentlandite domain is: NiEq = Ni% + (Cu% *
		0.995 * (3.65/8.00)) + (Co% * 0.951 * (15.30/8.00)) + (Pt% * 0.782 *
		(1100 * 14.583/8.00)) + (Pd% * 0.976 * (2300 * 14.583/8.00)) + (Rh%
		* 0.834 * (15500 * 14.583/8.00))
		•The calculation for the violarite domain is: NiEq = Ni% + (Cu% * 0.945
		* (3.65/8.00)) + (Co% * 0.885 * (15.30/8.00)) + (Pt% * 0.576 * (1100 *
		14.583/8.00)) + (Pd% * 0.873 * (2300 * 14.583/8.00)) + (Rh% * 0.648
		*(15500 * 14.583/8.00))
Relationship	• If the geometry of the mineralisation with respect to the drill hole	•N/A – geophysical data only
between	angle is known, its nature should be reported.
mineralisatio	• If it is not known and only the down hole lengths are reported, there
n widths and	should be a clear statement to this effect (eg ‘down hole length, true
intercept	width not known’).
lengths
Diagrams	• Appropriate maps and sections (with scales) and tabulations of	•Refer to figures in document.
	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 Exploration Results is not	•All drillhole locations are reported and a table of significant intervals is
reporting	practicable, representative reporting of both low and high grades	provided in the release text.
	and/or widths should be practiced to avoid misleading reporting of
	Exploration Results.
Other	• Other exploration data, if meaningful and material, should be reported	•Refer to document.
substantive	including (but not limited to): geological observations; geophysical
	survey results; geochemical survey results; bulk samples – size and

Duketon Mining Limited ACN 159 084 107 25 Richardson Street West Perth WA 6005 T: +61 473 798 006

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Criteria	JORC Code explanation	Commentary
exploration	method of treatment; metallurgical test results; bulk density,
data	groundwater, geotechnical and rock characteristics; potential
	deleterious or contaminating substances.
Further work	• The nature and scale of planned further work (eg tests for lateral	•A discussion of further work underway is contained within the body to
	extensions or depth extensions or large-scale step-out drilling).	this ASX release.
	• Diagrams clearly highlighting the areas of possible extensions,
	including the main geological interpretations and future drilling areas,
	provided this information is not commercially sensitive.

Duketon Mining Limited ACN 159 084 107

25 Richardson Street West Perth WA 6005 T: +61 473 798 006