GATEWAY MINING LIMITED — Capital/Financing Update 2019

Sep 19, 2019

ABN: 31 008 402 391 Level 11, 52 Phillips Street Sydney NSW 2000 GPO Box 225 Sydney NSW 2001 Tel: 61 2 8316 3998 Fax: 61 2 8316 3999 Website: www.gatewaymining.com.au

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ASX Announcement: 20th September 2019

DETAILED GRAVITY SURVEY TO HELP UNLOCK LONG-TERM EXPLORATION POTENTIAL AT GIDGEE GOLD PROJECT, WA

New high-quality geophysical dataset to pinpoint location of prospective Granodiorite contact, identify key controlling structures and refine drill targets

HIGHLIGHTS

• Detailed ground gravity survey recently completed over the majority of the Company’s highly prospective Gidgee Gold Project in WA. The survey covered an area of 162km[2 ] (Figures 1 and 2).

• The gravity survey has provided a high-quality dataset that will:

• Precisely locate the prospective contact of the Montague Granodiorite, allowing more accurate drill targeting.

• Provide the basis to develop a 3D model to understand the location of key geological contacts at depth.

• Define regionally significant structures that have a controlling effect on the locations of gold mineralisation.

• Integration of the gravity data with existing geophysical (e.g. airborne magnetic) and geochemical datasets will also facilitate targeting of other discovery opportunities across the wider Gidgee Project. These opportunities include:

• The identification of additional granitic intrusions similar to the Montague Granodiorite.

• Establishing the potential for syenitic intrusions, analogous to the multi-million ounce Wallaby gold deposit (Laverton District, WA).

• Locating sub-volcanic intrusions that for part of the volcanic hosted massive sulphide (VHMS) copper-zinc-gold system identified previously at Gidgee.

Gateway Mining Limited (ASX: GML) ( Gateway or Company ) is pleased to advise that it has completed a detailed ground-based gravity survey over the majority of its 100%-owned Gidgee Gold Project , Western Australia as part of its ongoing commitment to unlock the Project’s potential as a Tier-1 gold exploration and development opportunity.

The investment of time and money into collecting high-quality technical datasets provides a key platform for efficient and effective exploration and reflects Gateway’s commitment to technical excellence and the adoption of a systematic approach to exploration that leverages off the full range of available exploration methodologies.

Importantly, the Montague Granodiorite can be accurately modelled using gravity methods, providing the Company with a relatively effective and efficient exploration targeting strategy by allowing it to pinpoint the location of the prospective contact over its tenements.

Gravity surveys has proven to be an invaluable exploration targeting approach at other granite-hosted gold deposits in Western Australia such as Red 5’s King of the Hills deposit.

The gravity data will be integrated with existing geophysical, geochemical and geological datasets to provide a key platform for the Company’s ongoing targeting processes at Gidgee.

KEY POINTS

• The detailed ground gravity survey provides a high-quality dataset that clearly and precisely maps out the prospective contact of the Montague Granodiorite (Figures 1 and 2).

• Accurate positioning of the targeted contact allows for more effective planning of drilling programs.

• Modeling of the contact in 3D will provide a key understanding of the contact geometry at depth.

• The data provides greater clarity on the key structures interpreted to control the gold mineralisation across the wider Gidgee Gold Project.

• The data, particularly when integrated with the airborne magnetic data, allows for targeting of intrusions similar to the Montague Granodiorite that have not previously been identified in the region. These intrusions would be considered as high-ranking targets for future programs of exploration.

• In addition to the Montague analogue targets, gold deposit styles based on Kanowna Belle and Wallaby are considered as viable targets throughout the wider Gidgee Gold Project and will be actively targeted.

• Historical exploration has identified a significant volcanic hosted massive sulphide (VHMS) copper-zinc-gold system at the Flametree Prospect. This new gravity dataset can now be utilised to help identify sub-volcanic intrusions that would help focus any future exploration initiative targeting base metals.

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Figure (1): Gidgee Gold Project Recently acquired detailed gravity Image over open source regional gravity data (Tilt N_Shade)

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Figure (2): Gidgee Gold Project Recently acquired detailed gravity image with outline of the Montague Granodiorite (Tilt N_Shade)

GRAVITY SURVEY DETAILS (See Table 1 for details)

• The survey data was collected by Atlas Geophysics Pty Ltd, a Perth based geophysical contracting company.

• Gravity measurements were acquired using Scintrex CG-5 AUTOGRAV Gravity Meters (SN: 276 and 410811).

• GPS positions were acquired using CHC Nav i70 Base receiver and CHC i70 GNSS Rover Receivers

• Gravity data was acquired on a nominal grid of 200m x 200m station spacing with 100m X 100m infill acquired over high priority areas.

• Gravity and GPS data were independently reviewed and verified by Southern Geoscience Consultants Pty Ltd

MANAGEMENT COMMENT

Gateway’s Managing Director, Mr Peter Langworthy, said the Company’s decision to invest in a gravity survey in parallel with its other ongoing exploration initiatives reflected its strong commitment to apply world-class exploration practices to unlock the Project’s long-term potential.

“The amenability of the Granodiorite to modelling using gravity makes this a logical addition to our existing armoury of exploration data – which now includes extensive geophysical and geochemical datasets complemented by what we are learning from the drilling programs completed to date,” he said.

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“The ability to pinpoint the precise location of the Granodiorite contact should help enormously to target effective and efficient exploration along this highly prospective ‘skin’ or ‘surface’.

“At the same time, we will be able to accurately model major controlling structures and build a three-dimensional model which we believe will be a major breakthrough for our ongoing exploration of the Gidgee Project.

“The gravity data will also help us to unlock the potential of our ground to host other deposit styles, including VMSstyle base metal mineralisation.”

Peter Langworthy Managing Director

For and on behalf of GATEWAY MINING LIMITED

Competent Person Statement

The information in this report that relates to Exploration Results or Mineral Resources is based on information compiled or reviewed by Mr Peter Langworthy who is a full-time employee of Gateway Mining Ltd and is a current Member of the Australian Institute of Mining and Metallurgy. Mr Peter Langworthy has sufficient experience, which is relevant to the style of mineralisation and types of deposit under consideration and to the activities undertaken, to qualify as a Competent Person as defined in the 2012 Edition of the “Australasian Code of Reporting of Exploration Results, Mineral Resources and Ore Reserves”. Mr Langworthy consents to the inclusion in the report of the matters based on the information in the form and context in which it appears.

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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
Sampling	• Nature and quality of sampling (eg cut channels, random chips, or	•GNSS control was established for the new control station by
techniques	specific specialised industry standard measurement tools appropriate	submitting a 10 hour session of static data to AUSPOS, providing
	to the minerals under investigation, such as down hole gamma	coordinates of the base station to better than 10mm for the x, y and z
	sondes, or handheld XRF instruments, etc). These examples should	coordinates
	not be taken as limiting the broad meaning of sampling.	•Data were acquired in a single shift of up to 12 hours duration. Each
	• Include reference to measures taken to ensure sample representivity	shifty consisted of a single loop controlled by observations at the
	and the appropriate calibration of any measurement tools or systems	“South Gidgee” control station. Each loop includes at least two
	used.	repeats to establish drift control and provide an interlocking network
	• Aspects of the determination of mineralisation that are Material to the	of closed loops over the entire survey area.
	Public Report.	•No drilling results are included in this announcement
	• 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
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 ifso, by what method, etc). _
Drill sample	• Method of recording and assessing core and chip sample recoveries	•N/A
recovery	and results assessed.
	• 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 preferential
	loss/gainof fine/coarse material.
Logging	• Whether core and chip samples have been geologically and	•N/A
	geotechnically logged to a level of detail to support appropriate
	Mineral Resource estimation, mining studies and metallurgical

Criteria	JORC Code explanation	Commentary
	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 quarter, half or all core	•N/A
techniques	taken.
and sample	• If non-core, whether riffled, tube sampled, rotary split, etc and
preparation	whether sampled wet 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 of the assaying and	•Gravity measurements were acquired using Scintrex CG-5
assay data	laboratory procedures used and whether the technique is considered	AUTOGRAV Gravity Meters (SN: 276 and 410811)
and	partial or total.	•GPS positions were acquired using CHC Nav i70 Base receiver and
laboratory	• For geophysical tools, spectrometers, handheld XRF instruments, etc,	CHC i70 GNSS Rover Receivers
tests	the parameters used in determining the analysis including instrument	•One new Gravity / GNSS control station was established for the
	make and model, reading times, calibrations factors applied and their	survey (station 201910100001 – South Gidgee)
	derivation, etc.	•Gravity control for the new station was established via multiple tie-
	• Nature of quality control procedures adopted (eg standards, blanks,	loops with existing control station 201506300001 “Gidgee Camp”
	duplicates, external laboratory checks) and whether acceptable levels	•GNSS control was established for the new control station by
	of accuracy (ie lack of bias) and precision have been established.	submitting a 10 hour session of static data to AUSPOS, providing
		coordinates of the base station to better than 10mm for the x, y and z
		coordinates
		•Data were acquired in a single shift of up to 12 hours duration. Each
		shifty consisted of a single loop controlled by observations at the
		“South Gidgee” control station. Each loop includes at least two
		repeats to establish drift control and provide an interlocking network
		of closed loops over the entire survey area.
Verification of	• The verification of significant intersections by either independent or	•Gravity and GPS data were independently reviewed and verified by
sampling and	alternative company personnel.	Southern Geoscience Consultants Pty Ltd.
assaying	• 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. _

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Criteria	JORC Code explanation	Commentary
Location of	• Accuracy and quality of surveys used to locate drill holes (collar and	•All gravity positions are processed from the GNSS raw data (base
data points	down-hole surveys), trenches, mine workings and other locations	station and rover units) to produce positional data with sub-decimeter
	used in Mineral Resource estimation.	accuracy.
	• Specification of the grid system used.
	• Quality and adequacy of topographic control.
Data spacing	• Data spacing for reporting of Exploration Results.	•Gravity data were acquired using 200m x 200m stations spacing with
and	• Whether the data spacing and distribution is sufficient to establish the	100m x 100m infill acquired over high priority target areas
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 of	• Whether the orientation of sampling achieves unbiased sampling of	•Gravity station spacings were taken at a nominal spacing.
data in	possible structures and the extent to which this is known, considering
relation to	the deposit type.
geological	• 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
security
Audits or	• The results of any audits or reviews of sampling techniques and data.	•Gravity and GPS data were independently reviewed and verified by
reviews		Southern Geoscience Consultants Pty Ltd.

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, location and ownership including	•	E57/405, E57/417, E57/687, E57/688, E57/793, E57/807, E57/823,
tenement and	agreements or material issues with third parties such as joint		E57/824, E57/874, E57/875, E57/876, E57/888, E57/945, E57/1004,
land tenure	ventures, partnerships, overriding royalties, native title interests,		E57/1005, M57/48, M57/98, M57/99, M57/217, M57/429, M57/485,
status	historical sites, wilderness or national park and environmental		P57/1407, P57/1409, P57/1410, P57/1411, P57/1412 and P57/1413.
	settings.		Tenements E57/793, M57/429 and M57/485 are 75% Gateway
	• The security of the tenure held at the time of reporting along with any		Mining Ltd and 25% Estuary Resources Pty Ltd. The prospecting (P
	known impediments to obtaining a licence to operate in the area.		prefixed) tenements are held in Gateway Projects WA Pty Ltd’s name
			but owned and operated by Gateway Mining Ltd. All other remaining
			tenements are held in Gateway Mining Ltd’s name and are owned
			and operated by Gateway Mining Ltd.
Exploration	• Acknowledgment and appraisal of exploration by other parties.	•	Whistler open cut was mined from November 1990 (Polaris Pacific
done by other			NL)and ore was toll treated through the Herald mill. Little attention

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Criteria	JORC Code explanation	Commentary	Commentary
parties			was paid to mineralisation other than gold.
		•	Montague open cut was mined from 1989-1990 (Herald Resource
			Ltd) and ore was toll treated through the Herald mill. Little attention
			was paid to mineralisation other than gold.
Geology	• Deposit type, geological setting and style of mineralisation.	•	High grade gold in major shear systems on the margin of a granitoid
			intrusion.
Drill hole	• A summary of all information material to the understanding of the	•	No drilling was undertaken relative to this announcement
Information	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, weighting averaging techniques,	•	N/A
aggregation	maximum and/or minimum grade truncations (eg cutting of high
methods	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 important in the reporting of	•	N/A
between	Exploration Results.
mineralisation	• If the geometry of the mineralisation with respect to the drill hole
widths and	angle is known, its nature should be reported.
intercept	• If it is not known and only the down hole lengths are reported, there
lengths	should be a clear statement to this effect (eg ‘down hole length, true
	_width not known’). _
Diagrams	• Appropriate maps and sections (with scales) and tabulations of	•	Appropriate maps are included in the text of this announcement
	intercepts should be included for any significant discovery being
	_reported These should include, but not be limited to a plan view of _

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Criteria	JORC Code explanation	Commentary
	_drill hole collar locations and appropriate sectional views. _
Balanced	• Where comprehensive reporting of all Exploration Results is not	•N/A
reporting	practicable, representative reporting of both low and high grades
	and/or widths should be practiced to avoid misleading reporting of
	_Exploration Results. _
Other	• Other exploration data, if meaningful and material, should be reported	•Gravity data have been processed to generate enhanced imagery for
substantive	including (but not limited to): geological observations; geophysical	potential field interpretation along with previously acquired airborne
exploration	survey results; geochemical survey results; bulk samples – size and	magnetic data. 3D UBC inversion of gravity and magnetic data have
data	method of treatment; metallurgical test results; bulk density,	been performed to facilitate interpretation and targeting of structural
	groundwater, geotechnical and rock characteristics; potential	setting that host gold mineralisation. 2D forward modelling of gravity
	deleterious or contaminating substances.	and magnetic data are being undertaken to define orientation of
		contacts between mafic greenstones and intrusive granites.
Further work	• The nature and scale of planned further work (eg tests for lateral	•First pass drill testing over areas of interest.
	extensions or 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.

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