Great Southern Mining : Diamond Drilling Confirms Gold System at Southern Star

ASX: GSN

ASX ANNOUNCEMENT

14 February 2022

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Diamond Drilling Confirms Mineralised

Gold System at Southern Star

Highlights

• First two diamond holes completed by Great Southern Mining have confirmed a significant mineralised system at Southern Star.
• Both diamond holes intersected the target mineralised quartz dolerite unit and significant gold bearing assemblages were noted as part of a potentially larger system.
• Standout intersection from the two-hole diamond program:
• • 20m @ 1.7 g/t Au from 62m incl. 1.6m @ 13.2 g/t Au from 76.6m in 21SSDD001
• Four-daylitho-structural review by Outcrop Exploration coincided with diamond drilling to aid target refinement for upcoming Reverse Circulation program.
• Reverse Circulation drilling planned and set to commence this quarter.

Figure 1 - Structural analysis of recent diamond core undertaken by Marcus Willson from Outcrop Exploration

GSN's Executive Chairman, John Terpu, commented:

"Today's results confirm that Southern Star has all the hallmarks of a large mineralised gold system. The structural analysis of the diamond core has given GSN the first visual insight to what the gold mineralisation looked like in core and what structural and alteration assemblages are key for future targeting. The results clearly demonstrate the significance and potential of the deposit given the noted similarities of mineralisation to the much larger million-ounce open pit and underground gold mine at Rosemount and to the Ben Hur Deposit, both along strike on the same regional mineralised structure. We remain very excited at the potential of Southern Star and the wider Duketon Gold Project for continued exploration success."

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Introduction

Great Southern Mining Limited (ASX: GSN) ("GSN" or the "Company") is pleased to announce results from its maiden Diamond Drilling (DD) program from the Southern Star Gold Deposit at its 100% owned Duketon Gold Project located 45km north of Laverton, Western Australia.

A two hole 319.5m DD program has been completed at Southern Star. The purpose of this drilling was to obtain further insight into the gold mineralisation at Southern Star, which is open to the north, south and at depth. The two diamond holes were drilled 580m apart at opposite ends of the current known mineralisation, with the intention to examine the structural orientation of quartz veining, folding and foliation at the current extents of mineralisation.

Figure 2 - Southern Star insert highlighting maximum gold downhole with location of recent diamond holes, draped magnetic data (TMI1vd) highlighting the regional 345° trending stratigraphy that host both Regis Resources' Ben Hur and Southern star deposits.

Technical Discussion

Gold mineralisation at Southern Star is hosted in an east-dipping 345°- trending quartz-dolerite unit which is approximately 80m wide. The drilling was designed to target the footwall of the quartz dolerite unit as this is where the primary lode is persistent and of high-grade based on assessment to date. The high-grade mineralisation can be traced for over 700m of strike length and is open in all directions (Figure 2).

Major shearing runs the length of the deposit with gold mineralisation being associated with quartz veining and sulphides within the fractionated dolerite unit, pervasive foliation was observed in both diamond holes and strikes 345° which matches the regional strike and further supports the relationship between Ben Hur and Southern Star.

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The objective of the diamond drilling program was to build on the geological understanding of the deposit including the orientation of the structures controlling the gold mineralisation.

Diamond hole 21SSDD001 intersected a wide zone of multi-phased quartz veining from 56.6m to 80m. High- grade mineralisation was intersected within this zone of 20m @ 1.7 g/t Au from 62m including 1.6m @ 13.2 g/t Au from 76.6m. The high-grade interval corelates with previous recent Reverse Circulation drilling of 68m

• 1.9 g/t Au from 61m incl 4m @ 15.3 g/t Au from 89m and 5m @ 7.0 g/t Au from 114m in 21SSRC0036 (Figure 3).

Figure 3 - Cross section centered on 6880650mN highlighting previous RC drilling and recent diamond hole.

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Figure 4 - Diamond Core photo of 21SSDD001, highlighting high grade gold intervals (g/t Au) from 72m-78.4m with intense albite alteration overprinting and hydrothermal veining.

Intense sequence of alteration assemblages was observed, logging of alteration of the core took place and intense albite alteration with hydrothermal veining corelates well with the area of high-grade gold intervals (Figure 4 and Figure 5). Reviewing pathfinder data within the Leapfrog model, Bismuth, a known magmatic pathfinder, appears to correlate well with the zone of logged albite alteration.

Arsenic, a known basin/metamorphic pathfinder, appears to correlate well with the sericite/brown mica alteration, which was observed deeper downhole which corelates to a secondary zone of gold mineralisation with 8.3m @ 0.63 g/t Au from 110m intersected. This Arsenic-sericite zone sits adjacent to the albite-bismuth zone. This new understanding of alteration assemblages and pathfinder elements will be key in vectoring in on the high-grade mineralisation at Southern Star.

The second diamond hole (21SSDD002) intersected similar alteration assemblages although notably not as intense, a wide zone of quartz veining was also absent, selective sampling of the second hole from 114m to 131m was undertaken where albite alteration and a quartz veining (118-120m) was intersected. Although only limited intercepts of significant gold (>0.1 g/t Au) were intersected (0.9m @ 0.16 g/t Au from 117.1m and 0.7m @ 0.11 g/t Au from 120.6m), it is interpreted to be proximal to the mineralised zone due to the similarities in the alteration assemblages. The remainder of the core is currently being cut and multi-element analysis is been undertaken on both diamond holes.

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Figure - 5 Alteration zones (Albite and Sericite) logged in recent diamond core with grade shells of Bismuth (green) and Arsenic (blue) highlighting the spatial correlation of the alteration zones relative to gold (discs on drill traces) and pathfinder elements. Section centered on 6880650mN (After Wilson 2022).

Next Steps

Based on the success of today's results, the RC drill rig will immediately return to Southern Star for further drilling to test for strike extensions at Southern Star with a focus on strike extension to the south where no deep drilling has taken place.

This announcement is authorised by the Executive Chairman on behalf of the Board of GSN.

For Further Information Contact:

John Terpu, Executive Chairman [phone]

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