GREAT DIVIDE MINING LTD — Capital/Financing Update 2025

Oct 1, 2025

ASX Release

2 October 2025

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Drilling Commences at Coonambula Antimony-Gold Project

Highlights

• Dart Mining NL (ASX:DTM) commenced drilling at the Coonambula Joint Venture’s Banshee Antimony-Gold Prospect on 28 September 2025.

• First hole (CBADD001) intersected stibnite mineralisation 0.6m observed to be approximately 70% Stibnite at 42m. A second zone of stibnite massive sulphide veining was intersected at 70m downhole. First assays are expected to be returned in early November.

• DTM expects to complete 2,000m of HQ core drilling this calendar year.

• CEI-funded IP survey at Banshee has commenced with 12 of 15 lines completed to date.

Chief Executive Offer, Justin Haines, commented:

“ GDM entered into the JV with DTM to rapidly progress the Coonambula Project. DTM has made amazing progress in gaining all necessary approvals to commence site works and progressing drilling and geophysical surveys. With the first core displaying notably positive results, we look forward to receiving the initial results in the coming months. ”

Emerging gold producer and exploration company Great Divide Mining Ltd (the Company or GDM ) (ASX:GDM), is pleased to announce the commencement of exploration works at the Coonambula Antimony-Gold Project, SE Queensland.

The Coonambula Project is subject to a Joint Venture with Dart Mining NL (ASX:DTM) whereby DTM will earn up to 51% equity in the Coonambula Project upon completion of 4,000m of drilling and two annual resource reports, over the next 24-month period (from March 2025).

For further information on the Coonambula Project and the DTM farm-out, please see GDM’s ASX announcements “GDM to Farm-out Coonambula Antimony-Gold Project” of 12 March 2025 and “GDM Completes Farm-out of Coonambula Antimony-Gold Project” of 17 June 2025.

Drilling Commencement

DTM completed the necessary approvals and permissions for drilling activities during August and September 2025 and moved a portable camp to a nearby offsite location. Drilling of the first cored hole into the Banshee Antimony-Gold Prospect was commenced late in September 2025 with hole CBADD001 being drilled near the historic Banshee Antimony mine workings (Figure 1 and 2).

CBADD001 intersected massive sulphide mineralisation 0.6m observed to be approximately 70% Stibnite at 42m (Figure 3). A second zone of stibnite massive sulphide veining was intersected at 70m downholeFigure 3. First assays are expected to be returned in early November.

Great Divide Mining Ltd ACN 655 868 803 GPO Box 154 Brisbane QLD 4001 greatdividemining.com.au

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DTM’s drillers have reported excellent drilling and recovery rates. Sampling and analysis of the first drill core had not been completed as at the date of this announcement.

Drilling is expected to continue through to the end of 2025, with 2,000m of drilling being targeted for completion at the Banshee Antimony-Gold Prospect in that period.

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Figure 1 DTM's core rig onsite at the Banshee Prospect, Coonambula Project

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CBADD001 (Approx.)
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Figure 2 Banshee drill plan and 2024 trenching results (ASX: GDM to Farm-Out Coonambula Antimony-Gold Project - Mar 2025)

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Figure 3 Example of Stibnite veining from hole CBADD001 42.0 to 42.1m approximately. Note that this is provided as an example only as sampling and assay has not yet been completed. Results will be provided when available.

*Visual estimates of mineral abundance should never be considered a proxy or substitute for laboratory analyses where concentrations or grades are the factor of principal economic interest. Visual estimates also potentially provide no information regarding impurities or deleterious physical properties relevant to valuations

IP Geophysical Survey Commencement

GDM was awarded a prestigious CEI (Round 9) grant from the Queensland Government totalling $181,577 to fast-track the Banshee Antimony-Gold target within the Company’s Coonambula

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Project in SE Queensland. The grant was awarded for a detailed IP (geophysical) survey targeting strike and depth extensions to the high-grade Antimony-Gold veins at the historic Banshee Antimony-Gold mine.

The IP survey commenced as required in September and is expected to be completed during October 2025. The data will then be interpreted and the outcomes of the survey reported as soon as possible.

Initial checking of field data shows good responses across the completed lines (Figure 4).

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Figure 4 Initial field data checking of first 12 IP Survey lines. Final interpretation and reporting will be completed once final three lines are surveyed. Results will be released once the report is finalised.

For further information on the QLD Government Collaborative Exploration Initiative funding, please see GDM’s ASX announcements “GDM Awarded $181,577 grant to test Banshee Antimony-Gold Target” of 9 June 2025.

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ASX release authorised by the Board of Great Divide Mining Ltd.

For further information:

Justin Haines

Chief Executive Officer e: justin.haines@greatdividemining.com.au

About Great Divide Mining Ltd (ASX: GDM)

Great Divide Mining is a Gold, Antimony and critical metals miner, explorer and developer with five projects across 17 tenements (including two in application). GDM’s focus is on operating producing assets within areas of historical mining and past exploration with nearby infrastructure, thus enabling rapid development. Through a staged exploration and development programme, GDM intends to generate cash flow from its initial projects to support further exploration across its portfolio of highly prospective tenements.

Competent Person’s Statement

The information in this report has been prepared, compiled, and verified by Mr. Owen Greenberger (B.Sc. Geology), a Competent Person who is a Member of the Australian Institute of Geoscientists. Mr. Greenberger is Head of Exploration for Dart Mining. Mr. Greenberger has sufficient experience that is relevant to the style of mineralisation and type of deposits under consideration and to the activity being undertaken 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”. Mr. Greenberger takes responsibility for the exploration results, and consents to the inclusion in the report of the matters based on his information in the form and context in which it appears.

Forward-Looking Statements

This announcement may contain forward-looking information about the Company and its operations. In certain cases, forward-looking information may be identified by such terms as "anticipates", "believes", “should”, "could", "estimates", “target”, “likely”, “plan”, "expects", "may", “intend”, "shall", "will", or "would". These statements are based on information currently available to the Company and the Company provides no assurance that actual results will meet management's expectations. Forward-looking statements are subject to risk factors associated with the Company’s business, many of which are beyond the control of the Company. It is believed that the expectations reflected in these statements are reasonable, but they may be affected by a variety of variables and changes in underlying assumptions which could cause actual results or trends to differ materially from those expressed or implied in such statements. There can be no assurance that actual outcomes will not differ materially from these statements.

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Appendix 1

Table 1: Collar Details

Hole ID	Easting GDA94(MGA Zone 56)	Northing GDA94(MGA Zone 56)	RL	Dip	Azi
CBADD001	291938.695	7173899.755	237.19	-55	160

Table 2: Mineralisation Logging from CBADD001

From (m)	To (m)	Width (m)	Mineral	Style	Percent (%)	Comments
42	42.6	0.6	Stibnite	Vein	70	Massive Stibnite Vein
42.6	45.4	2.8	Pyrite	Disseminated	0.1
45.4	46.1	0.7	Stibnite	Vein	2	Vein
46.1	68.75	22.65	Pyrite	Disseminated	0.2	Trace Pyin Veins and Disseminated
68.75	69.15	0.4	Sb	Vein	50	Massive Stibnite Vein

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Appendix 2

JORC Code, 2012 Edition – Table 1 report template

Section 1 Sampling Techniques and Data

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

Criteria	JORC Code explanation	Commentary	Commentary
Sampling	• Nature and quality of sampling (eg cut	•	No sampling or results for the
techniques	channels, random chips, or specific specialised industry standard measurement tools appropriate to the		current drilling are reported and is not applicable
	minerals under investigation, such as
	down hole gamma 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,	•	Standard tube NQ diamond drilling
techniques	open-hole hammer, rotary air blast,		was utilised with bottom of hole
	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		core orientation completed every run. An Axis orientation tool was utilised.
	_and ifso, by what method, etc). _
Drill	• Method of recording and assessing core	•	Core recoveries for DD was
sample recovery	and chip sample recoveries and results assessed.		recorded by measuring the total amount of core between each core
	• Measures taken to maximise sample recovery and ensure representative nature of the samples. • Whether a relationship exists between		block. This was then compared to the recovery noted on the core block by the driller and any errors
	sample recovery and grade and whether		were rectified. The Rock Quality
	sample bias may have occurred due to		Designation (RQD) value is
	preferential loss/gain of fine/coarse material.		calculated by summing the total length of core in the run composed
			ofpieces of coregreater than 10 cm

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Criteria	JORC Code explanation	Commentary	Commentary
			in length. The recovery and RQD are
			both converted to a percentage of
			the recovery during the data entry
			phase.
Logging	• Whether core and chip samples have	•	The drill core has been geologically
	been 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		and geotechnically logged to a level to support appropriate mineral resource estimation, mining studies and metallurgical studies. Core is
	quantitative in nature. Core (or costean,		logged both qualitatively and
	channel, etc) photography.		quantitatively. Core and
	• The total length and percentage of the		photography is available.
	_relevant intersections logged. _
Sub-	• If core, whether cut or sawn and whether	•	No sampling or results for the
sampling techniques and sample	quarter, half or all core taken. • If non-core, whether riffled, tube sampled, rotary split, etc and whether sampled wet		current drilling are reported and is not applicable
preparation	or dry.
	• 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	•	No sampling or results for the
assay data and laboratory	of the assaying and laboratory procedures used and whether the technique is considered partial or total.		current drilling are reported and is not applicable
tests	• 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.
	• 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. _
Verification	• The verification of significant	•	No sampling or results for the
of sampling and	intersections by either independent or alternative company personnel. • The use of twinned holes.		current drilling are reported and is not applicable
assaying	• Documentation of primary data, data
	entry procedures, data verification,

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Criteria	JORC	Code explanation	Commentary	Commentary
		data storage (physical and
		electronic) protocols.
	•	Discuss any adjustment to assay
		data.
Location of	•	Accuracy and quality of surveys	•	The location of drill hole collars
data points		used to locate drill holes (collar and		were confirmed with a Trimble DA2
		down-hole surveys), trenches, mine workings and other locations used in Mineral Resource estimation.		receiver and Catalyst 0.3m Subscription set to MGA94 Grid
	•	Specification of the grid system		Datum (Zone 56)
		used.	•	Accuracy is variable but is expected
	•	Quality and adequacy of topographic		to be 0.3m
		control.	•	During the mapping and Collar
				pickup process with constant visual
				quality assessment conducted, the
				receiver maintained an accuracy
				level <0.4m.
			•	Down hole, multi-shot surveys were
				taken at 15m then a nominal 30 m
				interval where possible using a
				Trueshot survey tool. A 3m multi-
				shot survey was conducted at end
				of hole.
Data	•	Data spacing for reporting of	•	No sampling or results for the
spacing and distribution	•	Exploration Results. Whether the data spacing and distribution is sufficient to establish		current drilling are reported and is not applicable
		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.
Orientation	•	Whether the orientation of sampling	•	Drilling is typically orientated
of data in relation to geological structure	•	achieves unbiased sampling of possible structures and the extent to which this is known, considering the deposit type. If the relationship between the		perpendicular to the interpreted strike of mineralization where possible and a target declination of the drill hole of -55 degrees.
		drilling orientation and the
		orientation 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	•	No sampling or results for the
security		sample security.		current drilling are reported and is
				not applicable
Audits or	•	The results of any audits or reviews	•	No audits or reviews have been
reviews		of sampling techniques and data.		completed of sampling techniques.

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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	Commentary
Mineral	•	Type, reference name/number,	•	The Coonambula Project consists
tenement and land tenure status		location and ownership including agreements or material issues with third parties such as joint ventures, partnerships, overriding royalties, native title interests, historical sites,		of six contiguous Queensland exploration permits for minerals (EPMs): o EPM 15203 (Widbury),
		wilderness or national park and		o EPM 16216 (Lady
		environmental settings.		Margaret),
	•	The security of the tenure held at		o EPM 25260 (Coonambula),
		the time of reporting along with any known impediments to obtaining a licence to operate in the area.		o EPM 26743 (Eidsvold), and o EPM 28433 (Coonambula Extended).
			•	Each of the granted Coonambula
				tenements is currently held 100%
				by wholly owned subsidiaries of
				Great Divide Mining Ltd (GDM),
				namely GDM Coonambula Pty Ltd
				and GDM Yellow Jack Pty Ltd. Dart
				Mining Ltd has a joint venture
				agreement (Coonambula Joint
				Venture) to complete exploration
				works on the EPMs.
Exploration	•	Acknowledgment and appraisal of	•	Historical exploration in the
done by other		exploration by other parties.		Coonambula area has been
parties				undertaken by a number of parties
				since the 1970s, primarily
				targeting epithermal-style gold
				and base metal mineralisation.
			•	Work included regional geological
				mapping, soil and rock chip
				geochemistry, and limited
				geophysical surveys. More
				detailed exploration was carried
				out in the early 2000s by junior
				explorers, with emphasis on gold
				and antimony mineralisation
				associated with quartz veining.
			•	In 2013–2014, drilling programs
				were completed at the Banshee
				prospect under the direction of
				Paul Byrne. These programs tested
				near-surface quartz–sulphide
				veining and returned anomalous
				gold and antimony results.
			•	Data from these programs,
				including drill collar locations,

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Criteria	JORC	Code explanation	Code explanation	Commentary	Commentary
					assay results, and geological logs
					which were reported to the ASX by
					GDM
				•	Trenching programs were
					completed across the Banshee
					prospect to test surface
					geochemical anomalies and
					quartz–sulphide veining. These
					trenches exposed mineralised
					structures and returned
					anomalous gold and antimony
					values, providing key targets for
					subsequent drilling. The trenches
					themselves are historic
					(pre‑GDM), but GDM sampled and
					reported those trenches in 2024.
Geology	•	Deposit	type, geological setting	•	The Coonambula Project is located
		and style of mineralisation.			~25 km southwest of Eidsvold in
					southeast Queensland, within the
					northern New England Orogen.
				•	Bedrock geology is dominated by
					Carboniferous to Permian–Triassic
					granitoid intrusions of the
					Rawbelle Batholith, intruding older
					metasedimentary sequences.
				•	Mineralisation at the Banshee
					Prospect is hosted within east–
					west trending shear zones and
					lodes developed in and adjacent to
					the granitoid intrusives.
				•	The Banshee system is
					characterised by antimony–gold
					(Sb–Au) mineralisation, with
					geological similarities to the
					Hillgrove Sb–Au deposit in New
					South Wales.
				•	Mineralisation occurs as stibnite ±
					quartz veins and breccia zones,
					with associated gold enrichment.
Drill hole	•	A summary of all information		•	Drillhole information has been
Information		material to the understanding of the exploration results including a tabulation of the following			included in the release in Appendix 1.
		information for all Material drill
		holes:
		o	easting and northing of the
			drill hole collar
		o	elevation or RL (Reduced
			Level – elevation above

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Criteria	JORC	Code explanation	Commentary	Commentary
		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 methods
aggregation methods		weighting averaging techniques, maximum and/or minimum grade		have been applied.
		truncations (eg cutting of high
		grades) and cut-off grades are
		usually Material 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	•	Mineralisation widths are reported
between mineralisation widths and intercept lengths	•	important in the reporting of Exploration Results. If the geometry of the mineralisation with respect to the drill hole angle is known, its nature		as the downhole length. Final interpretation and inclusion of sample results will allow for true width calculations to be applied.
		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	•	Included in the body of the
		(with scales) and tabulations of		announcement.
		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 mineralisation intersected in
reporting		all Exploration Results is not practicable, representative reporting of both low and high		the completed hole has been included
		grades and/or widths should be

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Criteria	JORC	Code explanation	Commentary	Commentary
		practiced to avoid misleading
		_reporting of Exploration Results. _
Other	•	Other exploration data, if	•	No other material data is
substantive exploration		meaningful and material, should be reported including (but not limited		presented in this announcement.
data		to): geological 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	•	Plans for further work are outlined
	•	further work (eg tests for lateral extensions or depth extensions or large-scale step-out drilling). Diagrams clearly highlighting the areas of possible extensions,		in the body of the announcement which include analysis of the drill core and continued drilling of Dart Mining’s planned locations.
		including the main geological
		interpretations and future drilling
		areas, provided this information is
		not commercially sensitive.

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