For personal use only

Activities Report for the Quarter Ended 30 June 2022

13 July 2022

Mount Ridley Mines Ltd (ASX: MRD) (or "the Company") is pleased to provide the following report for

the Quarter ending 30 June 2022.

HIGHLIGHTS

  • A further 328 aircore holes completed this quarter, targeting regional rare earth element (REE) mineralisation at the Company's Mount Ridley Project.
  • A total of 409 holes have now been completed for 18,927m with 8,497 samples at the laboratory. A shortage of personnel at the laboratory has resulted in extensive delays in assay turn-around time.
  • A program of works ("POW") has been approved for Stage 3 - Primary Target expansion drilling, which will resume after the winter rain cycle.
  • The POW provides for another 20,000m of aircore drilling within an area of 250km2 which includes the Keith's, Marcellus', and Winston's Prospects where extensive REE mineralisation has been intersected in earlier Company aircore drilling.

MOUNT RIDLEY REE PROJECT DRILLING

The 100%-held Mount Ridley Project comprises 9 granted exploration licences in south-west Western Australia with an area of approximately 3,400km2 (refer to figure 1). The Company undertook drilling adjacent to known REE mineralisation at the Winston's Prospect and first-pass Regional Drilling throughout the Project where accessible tracks were available, using two aircore drilling rigs for much of the time. When drilling halted, 409 holes for 18,927m had been completed. The Company's strategy is to avoid cultivated land, and this phase of drilling was restricted to existing cleared, dry tracks.

Stage 1 - Primary Target Infill Drilling: 64 aircore holes drilled for 3,168m along the north-western flank

of the known mineralisation at the Winston's Prospect.

Stage 2 - Regional Drilling: 345 aircore holes drilled for 15,759m, spaced 400m apart along existing tracks, to locate previously unrecognised zones of REE mineralisation. It is likely that REE mineralisation will be deposited in anastomosing channels within the greater Eocene-aged Bremmer Basin.

DRILLING TO RESUME AFTER WINTER RAIN

Drilling will resume when dry soil conditions prevail later this year. Two phases will then be undertaken comprising:

Stage 2 - Regional Drilling (continued): Subject to the results from the current round of drilling, anomalous drill holes, currently spaced 400m apart, will be infilled to 200m spacings. Emphasis will be

For personal use only

placed on following up high grade total rare earth oxides (TREO1), high proportion of critical rare earth oxides (CREO2) and areas of shallow cover.

Stage 3 - Primary Target Expansion: Currently planned 20,000m of drilling designed to straddle mineralisation at the Winston's and Keith's Prospects. This will include 8 drill traverses with a total length of 75km, with each drill traverse spaced at approximately 2km intervals, with holes spaced at 200 or 400m apart (refer to figure 2) along each traverse.

Figure 1: The Mount Ridley REE Project comprises 9 granted exploration licences in south-west Western Australia with an area of approximately 3,400km2.

This drilling programme is designed to test an expanded area surrounding the intersections listed in table 1 and shown in figures 2-6. The Company is implementing an Aboriginal Heritage Management Plan with the Esperance Tjaltjraak Native Title Aboriginal Corporation ("RNTBC") and has developed an Exploration Environment Management Plan in conjunction with Government environmental bodies to facilitate the establishment of new drilling access for this drilling programme.

1 TREO means the sum of the 14 REE+Y, each converted to its respective element oxide equivalent using the formulae in Table 4 (See references). 2 Critical or CREO means Critical Rare Earth Oxides; the sum of Dy2O3, Eu2O3, Nd2O3, Tb4O7 and Y2O3

For personal use only

EXPLORATION REVIEW

The Company announced on 1 July 2021 that laterally extensive REE mineralisation had been identified at its namesake Mount Ridley Project3, near Esperance. REE mineralisation is thought to occur within Eocene-aged sediments of the Bremmer Basin. Drill holes that have returned elevated REE extend over an area 25 kilometres long and 3 kilometres wide, representing approximately 2% of the Project area, and mineralisation is 'open' in all directions (refer to figure 2 and figures 3-6).

Work undertaken to date

  • Initially, composite samples from over 3,500m of drilling were analysed for REE using a 'total digest' fusion technique ("Fusion"), designed to report the total amount of REE in each sample.
  • A second analysis of higher grade REE samples was completed using a 'partial digest' weak aqua regia digestion technique ("AR4") which would take into solution only the most soluble or loosely bound REE, a feature of ionic adsorption clay REE deposits. This test indicated that at a grade of approximately 800ppm TREO, 80% of light REO5, 76% of heavy REO6 and 80% of CREO were taken into solution under the conditions trialled.
  • 880 drill pulps have been analysed using a short wave infra-red ("SWIR") instrument to help map clay minerals distribution as a component of an ongoing Research and Development project studying the REE mineralisation genesis.
  • 344 samples were scanned using a Bruker M4 Tornado micro-XRF analyser. Samples were of near fresh rock stubs from the bottom of aircore holes drilled in 2014. Results are also a component of the Research and Development project.
  • Drilling statistics for the 2022 programme to date include a total of 409 aircore holes for 18,927m with 8,497 samples submitted for analysis.

3 Mount Ridley Mines Limited announcements to ASX 1 July 2021,2 August 2021, 13 September 2021

4 AR means Weak aqua regia acid, a mix of 1 molar hydrochloric acid (HCl) and 1 molar nitric acid (HNO3).

5 Light REO or LREO means Light Rare Earth Oxides; the sum of La2O3, CeO2, Pr6O11, Nd2O3, Sm2O3, Eu2O3.

6 Heavy REO or HREO means Heavy Rare Earth Oxides; the sum of Gd2O3, Tb4O7, Dy2O3Ho2O3, Er2O3, Tm2O3, Yb2O3, Lu2O3, Y2O3.

For personal use only

Photograph 1: Aircore drilling at the Mount Ridley Project.

Project Geology

Archaean to Meso-Proterozoic Basement

  • Geological Survey of Western Australia mapping7 shows that basement rocks are interpreted to be Archaean to Meso-Proterozoic-aged gneisses and granites, in parts intermixed with mafic and ultramafic rocks.
  • Basement rocks protrude through younger sediments, forming northeast trending ridges and inselbergs (figure 2). Basement ridges likely control the size and shape of the overlying, REE- mineralised, Eocene-aged basins.
  • Certain ultramafic rocks are considered prospective for nickel mineralisation.

Eocene

  • Eocene-agedsediments fill the onshore Bremmer Basin, infilling depressions in the Meso- Proterozoic-aged basement.
  • The Eocene sediments comprise siltstone, sandstone, spongolite, limestone and lignite. Early indications suggest that unconsolidated kaolin- or montmorillonite- rich clays host the Mt Ridley

rare earth mineralisation (refer to figures 4 and 6).

Recent

  • The current land surface is dominated by deposits of sand and gypsum dunes around numerous ephemeral lakes.

7 (DMIRS) Department of Mines, Industry Regulation and Safety 1:250,000 Interpreted Bedrock Geology (2020)

r personal use only

Figure 2: Drilling Location Plan by Drilling Stage.

This is an excerpt of the original content. To continue reading it, access the original document here.

Attachments

  • Original Link
  • Original Document
  • Permalink

Disclaimer

Mount Ridley Mines Limited published this content on 12 July 2022 and is solely responsible for the information contained therein. Distributed by Public, unedited and unaltered, on 12 July 2022 22:33:06 UTC.