St George Mining : Exploration Update - Mt Alexander

ASX / MEDIA RELEASE

29 March 2022

EXPLORATION UPDATE - MT ALEXANDER HIGH-GRADE NICKEL-COPPER PROJECT

New compelling targets identified, diamond drilling continues

HIGHLIGHTS

Large conceptual targets identified:

• • Comprehensive project-wide review has highlighted five large conceptual targets for nickel-copper-PGE mineralisation, most with minimal or no previous drilling

• • These targets have favourable structural and geological settings for nickel-copper-PGE deposits and warrant prioritised follow-up exploration

• • Compelling conceptual targets identified for drilling include:

  •  Ida Fault: structurally complex area where the Cathedrals Belt is truncated by the craton-scale Ida Fault; the interpreted shallow westerly plunge to high-grade mineralisation towards the Ida Fault suggests the Ida Fault may be linked to mineralisation

  •  Radar and Fish Hook: two large structural targets - Radar and Fish Hook - in the eastern extension of the Cathedrals Belt, with very limited follow-up drilling at Radar - MAD152 intersected 4.0m @ 3.0%Ni, 1.1% Cu, 2.2g/t PGE from 48m

  •  Granite/greenstone contact: the interpreted contact and related structures between the Mt Alexander greenstone belt and the granites located directly north is considered prospective and has yet to be effectively explored

Major expansion of seismic coverage:

• • Recent drilling has confirmed the trial seismic survey was effective in mapping the interpreted structures that host the mineralised intrusions at Mt Alexander

• • Based on the success of the trial survey in identifying potential mineralised intrusions, an expanded seismic survey is planned to commence next month

• • The additional seismic coverage will cover high-priority target areas and has the potential to provide an exploration breakthrough

Growth of known high-grade deposits:

• • Infill and extensional drilling is continuing in areas of known high-grade nickel-copper-PGE mineralisation, including at the Investigators and Stricklands Deposits which remain open

• • Strong downhole EM conductor (22,800 Siemens) identified at West End, near the western end of known mineralisation, suggests mineralisation is open towards the Ida Fault

ST GEORGE MINING LIMITED ACN 139 308 973

Suite 2, Level 2, 28 Ord Street West Perth WA 6005 |PO Box 100 West Perth WA 6872

www.stgeorgemining.com.au | Phone [phone]

1

Growth-focused Western Australian nickel company St George Mining Limited (ASX: SGQ) ("St George" or "the Company") is pleased to provide an update on current activities and planned exploration programmes at its flagship high-grade nickel-copper-PGE Mt Alexander Project, located in the northern Yilgarn Craton.

The Company's exploration strategy is two-fold: firstly, to expand areas of known high-grade massive sulphide mineralisation intersected near surface at Mt Alexander and, secondly, at the same time test several large conceptual targets that have potential to deliver a step change in the scale of the Mt Alexander Project.

Following a comprehensive review of all available technical data for St George's extensive holdings at Mt Alexander, five conceptual target areas with minimal or no previous drilling have been identified for priority testing.

Work on these conceptual target areas is planned to commence on site early in the June quarter.

John Prineas, St George Mining's Executive Chairman, said:

"Our systematic exploration continues to deliver encouraging results that support the potential for further significant mineralisation at Mt Alexander.

"With surface EM surveys having limited detection at depth, the seismic survey has been invaluable in mapping the host structures and revealing prospective areas for exploration. Further seismic surveys will assist with 3D structural interpretation and provide datasets needed to make more discoveries.

"The geological and structural interpretations continue to evolve with new exploration results. Our very experienced and committed technical team is also looking at new concepts and methods to provide additional information that can assist exploration targeting.

"With investor interest in quality nickel exploration opportunities continuing to grow enormously, we are energised by these new exploration initiatives which could help to add to the four shallow high-grade nickel-copper discoveries we have already made across the Cathedrals Belt.

"We are also looking forward to the initial diamond drilling programme at the Paterson Project, in the eastern Pilbara region of WA, that will commence soon.

"This programme will test a number of compelling drill targets for potential copper and gold mineralisation and deliver some exciting newsflow to complement our activities at Mt Alexander.

"With advanced exploration underway around the known high-grade deposits at the Cathedrals Belt and recognition of five large, conceptual targets at Mt Alexander - plus the commencement of diamond drilling at Paterson - this year is shaping as very productive for the Company and a very exciting time for St George shareholders."

MT ALEXANDER - GEOLOGICAL AND STRUCTURAL SETTING OF Ni-Cu-PGE MINERALISATION

The high-grade Ni-Cu-PGE mineralisation at Mt Alexander is structurally controlled, making an understanding of the structural setting critical to exploration targeting. The latest seismic data and drill results have provided important information on the structural setting of the Mt Alexander Project.

The main interpreted geological and structural elements at Mt Alexander are as follows and illustrated in Figures 1 and 2 below:

• • 15km-long, east-northeast oriented Cathedrals Belt with mafic intrusions hosting Ni-Cu-PGE sulphides over a strike of more than 5km

• • Mt Alexander greenstone belt trending north-south that hosts wide mafic-ultramafic sequences south of the Cathedrals Belt

• • Extensive area of granite intrusion, north of the greenstone belt and east of the Ida Fault

• • Near surface, high-grade deposits dipping north and interpreted to plunge to west and east (Fig 2)

• • Multiple structures parallel to Cathedrals Fault within ~5km-wide belt north of greenstone belt

• • Ida Fault is a major craton-scale domain boundary, which may be linked to the mafic intrusions

Figure 1: Mt Alexander Project: Highlighting conceptual target areas (black ellipses) over reduced to pole aeromagnetic image with interpreted structures and mafic dykes or sills, and the interpreted position of the

Ida Fault (Base image provided by CSIRO as part of the Mt Alexander co-funded research project).

Figure 2: Top: Cathedrals Belt schematic long projection at approximately 6806800N extending 15km east-west showing extent of current drilling and three conceptual targets. Bottom: Zoomed in view of long projection showing interpreted shallow plunge of high-grade mineralisation towards the west.

LARGE CONCEPTUAL TARGETS IDENTIFIED

A comprehensive review of all available geological, geophysical and structural data at Mt Alexander has identified five large conceptual target areas where there has been minimal or no prior drilling. All five targets are located in underexplored areas of the Mt Alexander Project.

The five target areas (numbered 1-5) are briefly summarised below with locations shown on Figure 1. Three of the target areas (numbers 1, 2 and 3) are also shown on the long section (Figure 2).

• 1 Ida Fault

  • • Intersection of the Ida Fault and the Cathedrals Belt

  • • Ida Fault represents a well-documented, major intra-cratonic domain boundary

  • • Comprises a wedge of structural complexity >2km west of previous drilling with no effective electromagnetic (EM) survey of the area

  • • Ida Fault may be a potential conduit to mafic intrusions along Cathedrals Belt

• 2 Radar Prospect

  • • 2 to 3km long interpreted structural anomaly with interpreted basal intrusive, 1.5km east of Cathedrals Deposit along the Cathedrals Belt

  • • Previous shallow intersection in MAD152 with 4m @ 3.0% Ni, 1.1% Cu and 2.2g/t PGE from 48m; drilling planned to follow up as soon as possible

  • • Minimal drilling and no effective surface EM coverage over northern portion of Radar target

• 3 Fish Hook Prospect

  • • >4km long, 1km wide structural zone with multiple intrusive units interpreted from magnetic data; located 5km east of high-grade Cathedrals Deposit along Cathedrals Belt

  • • Fish Hook is the largest section of Cathedrals Belt with minimal drilling to shallow depth only

• 4 Granite/Greenstone Contact

  • • Extensive area of granite/greenstone contact, north of outcropping central greenstone belt

  • • Comprises interpreted stoped-out and structurally disrupted granite/greenstone contact

  • • Favourable structures and possible mafic intrusions along the contact are considered to be priority targets for mineralisation

  • • No prior effective drilling to test the granite/greenstone contact

5

Bullseye Anomaly

• • Untested gravity and magnetic anomaly 1km north of Stricklands Deposit

• • Similar geological setting to Stricklands Deposit within a prospective east-west structure

• • Walk-up drill target

Drilling will be accelerated to test these targets. Geophysical surveys including gravity and seismic surveys are also planned to further investigate these new conceptual targets.

EXPANSION OF SEISMIC PROGRAMME

The trial seismic survey completed in September 2021 comprised three north-south 2D seismic lines that covered an east-west strike of ~3km in the West End/Investigators area of the Cathedrals Belt. The trial survey did not cover the Stricklands and Cathedrals Deposits where shallow high-grade massive nickel-copper sulphides have been discovered with mineralisation open at depth.

Interpretation of the trial seismic data with results from drilling the S1, S2 and S3 targets confirmed that seismic had successfully mapped the prospective structures that host the mineralised intrusions at the Project.

Following the success of the trial seismic survey, a further substantial seismic survey will be undertaken to investigate the conceptual targets outlined in this release and assist in generating a 3D model of the Cathedrals Belt and other structures. Approximately eight seismic lines are planned, starting early in the June quarter.

Depending on results, this survey could be expanded further to delineate favourable structures and contacts where massive sulphide mineralisation might have accumulated.

Figure 3 - Plan view of interpreted Cathedrals Belt (against magnetic RTP 1VD) showing the trial seismic lines (yellow), and planned extensional seismic lines (blue).