DIATREME RESOURCES LIMITED — M&A Activity 2024

Jul 8, 2024

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ASX ANNOUNCEMENT

9 July 2024

Extension of Offer Period and Acceleration of Payment Terms

Diatreme Resources Limited (ASX: DRX) ( Diatreme or the Company ) refers to its off-market takeover bid for all the ordinary shares in Metallica Minerals Limited (ASX: MLM) ( Metallica ), under which Metallica Shareholders would receive 1.3319 ordinary shares in Diatreme ( Diatreme Shares or the Offer Consideration ) for each ordinary share in Metallica ( Metallica Share ) held by Metallica Shareholders on the record date ( Offer ). The Offer is contained in Diatreme’s bidder’s statement dated 28 March 2024 (as varied and supplemented from time to time) ( Bidder’s Statement ). Words defined in the Bidder’s Statement have the same meaning in this announcement, unless the context requires otherwise.

Extension Rationale

Diatreme notes a marked acceleration in acceptances now currently standing at 79.67% (as at 8 July 2024), feedback from calls and messages received by Diatreme indicates many Metallica Shareholders require longer than the current Offer period to effect the necessary procedures to accept.

Additionally, Diatreme’s acquisition of more than 75% of Metallica Shares under the Offer was an important first step in meeting the anticipated conditions for a delisting of Metallica with the extension of the Offer period by a further two weeks satisfying another of the ASX’s anticipated requirements.

For these reasons, Diatreme has decided to extend the Offer period to facilitate further acceptances.

Extension of Offer Period

The Offer Period has been extended and is now due to close on Tuesday, 23 July 2024 , unless extended. Diatreme encourages all Metallica Shareholders to ACCEPT THE OFFER NOW AND NOT WAIT . Information regarding the formal extension of the closing date for the Offer is set out below.

Acceleration of payment terms

Diatreme has today announced an acceleration of the payment terms under the Offer. Subject to the terms of the Offer:

• Metallica Shareholders that had validly accepted the Offer prior to 7.00pm (Sydney time) on 5 July 2024 will be issued the Offer Consideration on or before 12 July 2024; and

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• Metallica Shareholders that have accepted or do accept the Offer after 7.00pm (Sydney time) on 5 July 2024 will be issued the Offer Consideration within 10 Business Days of validly accepting the Offer. Under these payment terms, it is expected that Metallica Shareholders that have validly accepted the Offer by 7.00pm (Sydney time) each Friday will be issued the Offer Consideration in the following week.

Ineligible Foreign Shareholders and Small Parcel Holders

Metallica Shareholders that are Ineligible Foreign Shareholders or Small Parcel Holders are not entitled to receive Diatreme Shares under the Offer. Ineligible Foreign Shareholders and Small Parcel Holders who accept the Offer will instead have their Offer Consideration sold by the Nominee on ASX and will receive in cash their share of the net proceeds from the sale of all Diatreme Shares sold by the Nominee. A Metallica Shareholder that accepts the Offer will be a Small Parcel Holder if the Diatreme Shares they are entitled to receive as Offer Consideration is a Small Parcel. Further information is set out in clause 5.3 of the Offer Terms in Schedule 1 of the Bidder’s Statement.

How to Accept the Offer

Instructions on how Metallica shareholders can accept the Offer are contained in the Bidder’s Statement and on the acceptance form (which accompanies the Bidder’s Statement). Metallica shareholders can accept the offer by returning their acceptance form or contacting their controlling participant (usually their broker).

To ACCEPT the offer online, scan the barcode to the right with your smart phone or tablet or visit https://investor.automic.com.au/#/signup on your browser and follow these instructions:

1. Click “Register” then select "Metallica Minerals Takeover Offer" from the dropdown list in the Issuer Name Field

2. Enter your Holder Identification Number / Holder Reference (HIN/SRN)

3. Enter your postcode OR country of residence (only if outside Australia)

4. Tick the box "I'm not a robot" and then select "Next"

5. Complete the prompts to set up your username and password details

6. Once you are logged in, select “Offers” from the left-hand vertical menu and follow the prompts.

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Any Metallica shareholders with questions about the Offer, should contact their legal, financial or other professional adviser or call the shareholder information line on 1300 636 752 (or +61 2 8318 7933 for overseas domiciled holders) between 8.30am (Sydney time) and 5.00pm (Perth time) Monday to Friday.

Notice of Variation

Enclosed with this announcement is a notice under section 650D(1) of the Corporations Act 2001 (Cth) ( Corporations Act ) extending the closing date for the Offer to 7.00pm (Sydney time) on 23 July 2024 ( Notice of Variation ). The Notice of Variation has been lodged today with ASIC, served on Metallica, and despatched to each Metallica shareholder and other person referred to in section 650D(1)(c) of the Corporations Act (as modified by ASIC Corporations (Takeover Bids) Instrument 2023/683 ). In accordance with section 650D(2) of the Corporations Act, Metallica Shareholders that have already accepted the Offer will not receive a copy of the Notice of Variation.

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In accordance with section 110D of the Corporations Act, despatch of the Notice of Variation occurred by the following means:

• Metallica securityholders who have provided Metallica with an electronic address for the purposes of receiving electronic copies of securityholder communications have been sent to their electronic address an email providing a link to an electronic copy of the Notice of Variation ( Electronic Letter ); and

• Metallica securityholders who have not provided Metallica with an electronic address for the purposes of receiving electronic copies of securityholder communications have been sent to their registered postal address a letter providing a link to an electronic copy of the Notice of Variation ( Access Letter ).

A copy of the Electronic Letter and the Access Letter is enclosed with this announcement.

This market announcement was authorised for release by:

Neil McIntyre Chief Executive Officer

Contact – Mr Neil McIntyre - Ph – +61 (0)7 3397 2222 Website - www.diatreme.com.au Email - manager@diatreme.com.au

For investor/media queries, please contact: Anthony Fensom, Fensom Advisory anthony@fensom.com.au Ph: +61 (0)407 112 623

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About Diatreme Resources Limited

Diatreme Resources Limited (ASX:DRX) is an emerging Australian producer of mineral and silica sands based in Brisbane. Our key projects comprise the Northern Silica Project and Galalar Silica Sand Project in Far North Queensland, located next to the world's biggest silica sand mine at Cape Flattery.

In Western Australia’s Eucla Basin, Diatreme’s ‘shovel-ready’ Cyclone Zircon Project is considered one of a handful of major zircon-rich discoveries of the past decade. Diatreme also holds a 49% interest in the Clermont Copper-Gold Project located in central Queensland. Diatreme has a farm-in agreement with Metallica Minerals Limited (MLM) which already owns a 51% interest and has provided its intention to earn up to a 75% interest by meeting certain further expenditure obligations of an additional $1 million.

Diatreme has an experienced Board and management, with expertise across all stages of project exploration, mine development and project financing together with strong community engagement skills.

Global material solutions group Sibelco Asia Pacific is Diatreme’s development partner on its Queensland silica projects portfolio. Sibelco Asia Pacific has completed a two tranche investment of $35 million taking its total project interest to 26.8%, with the balance (73.2%) held by Diatreme. In addition, Sibelco Asia Pacific made a $13.97 million investment at the corporate level.

For more information, please visit www.diatreme.com.au

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DIATREME RESOURCES LIMITED ACN 061 267 061

• To: Australian Securities and Investments Commission ( ASIC )

Metallica Minerals Limited ACN 076 696 092 ( Metallica )

Each Metallica shareholder and other person referred to in section 650D(1)(c) of the Corporations Act 2001 (Cth) ( Corporations Act ) (as modified by ASIC Corporations (Takeover Bids) Instrument 2023/683)

NOTICE OF VARIATION

SECTION 650D CORPORATIONS ACT 2001 (Cth)

This notice is given by Diatreme Resources Limited ACN 061 267 061 ( Diatreme ) in respect of the offers dated 11 April 2024 made by Diatreme under its off-market takeover bid to acquire all of the ordinary shares in Metallica ( Offers ). The Offers are contained in Diatreme’s bidder’s statement dated 28 March 2024 (as varied by notices dated 17 May 2024, 24 May 2024, 3 June 2024, 6 June 2024 and 25 June 2024, and as supplemented by the first supplementary bidder’s statement dated 10 April 2024, second supplementary bidder’s statement dated 17 April 2024, third supplementary bidder’s statement dated 8 May 2024 and fourth supplementary bidder’s statement dated 5 June 2024) ( Bidder’s Statement ). Unless the context requires otherwise, terms defined in the Bidder’s Statement have the same meaning in this notice.

A copy of this notice was lodged with ASIC on 9 July 2024. Neither ASIC nor any of its officers takes any responsibility for the content of this notice.

1 Variation of Offer – Extension of Offer Period

Diatreme hereby gives notice for the purposes of section 650D of the Corporations Act that each of the Offers are varied by:

• (a) extending the period during which the Offers will remain open for acceptance until 7.00pm (Sydney time) on 23 July 2024 (unless further extended under the Corporations Act); and

• (b) replacing ‘9 July 2024’ with ‘23 July 2024’ in each place that the closing date of the Offer, or the end of the Offer Period, is referenced in the Bidder’s Statement (including in the Acceptance Forms).

2 Approval of this notice

This notice has been approved by a unanimous resolution passed by the directors of Diatreme under section 650D(3A) of the Corporations Act, as inserted by ASIC Corporations (Takeover Bids) Instrument 2023/683.

Dated 9 July 2024

Signed for and on behalf of Diatreme Resources Limited

by:

Wayne Swan Chairman

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DIATREME RESOURCES LIMITED OFF-MARKET TAKEOVER BID

FOR METALLICA MINERALS LIMITED

Dear Metallica securityholder,

We refer to the off-market takeover bid by Diatreme Resources Limited ( ASX : DRX , Diatreme ) under Chapter 6 of the Corporations Act 2001 (Cth) ( Corporations Act ) for all the fully paid ordinary shares in Metallica Minerals Limited ( ASX : MLM , Metallica ) ( Offer ).

EXTENSION OF OFFER PERIOD

Please be advised that Diatreme has today lodged a notice of variation with ASIC, which includes an extension to the closing date of the Offer to 7.00pm (Sydney Time) 23 July 2024 ( Notice of Variation ).

The Notice of Variation can be downloaded by clicking here.

If you have any questions in relation to the Offer, please call the Metallica Offer Information Line Monday to Friday, between 8.30am and 7.00pm (Sydney time) on 1300 636 752 (within Australia) and +61 2 8318 7933 (outside Australia), or by email to hello@automicgroup.com.au.

Yours sincerely Tuan Do Company Secretary Diatreme Resources Limited

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«Registration_Details_Line_1» «Registration_Details_Line_2» «Registration_Details_Line_3» «Registration_Details_Line_4» «Registration_Details_Line_5» «Registration_Details_Line_6»

Diatreme Resources Limited

Unit 8, 55-61 Holdsworth Street Coorparoo Queensland 4151, Australia

https://diatreme.com.au/

9 July 2024

Dear Metallica securityholder,

RE: OFFER UPDATE AND NOTICE OF VARIATION - DIATREME RESOURCES LIMITED OFF-MARKET TAKEOVER BID FOR METALLICA MINERALS LIMITED

We refer to the off-market takeover bid by Diatreme Resources Limited ( ASX: DRX, Diatreme ) under Chapter 6 of the Corporations Act 2001 (Cth) ( Corporations Act ) for all the fully paid ordinary shares in Metallica Minerals Limited ( ASX: MLM, Metallica ) ( Offer ).

Please be advised that Diatreme has today lodged a notice of variation with ASIC, which includes an extension to the closing date of the Offer to 7.00pm (Sydney Time) 23 July 2024 ( Notice of Variation ).

WHERE CAN I ACCESS THE NOTICE OF VARIATION AND BIDDER’S STATEMENT?

The Diatreme Notice of Variation, along with the Bidder’s Statement and personalised acceptance form, can be viewed and downloaded by following the steps in one of these options:

I already have an online account with the Automic Share Registry

https://investor.automic.com.au/#/home 1. Select: “Existing Users Sign In”. 2. Once you have successfully signed in, click on “Documents and Statements”.

I don’t have an online account with the Automic Share Registry

https://investor.automic.com.au/#/signup 1. Click “Register” then select "Metallica Minerals Takeover Offer" from the dropdown list in the Issuer Name Field 2. Enter your Holder Identification Number / Holder Reference Number (HIN/SRN) 3. Enter your postcode OR country of residence (only if outside Australia) 4. Tick the box "I'm not a robot" and then select "Next" 5. Once you have successfully signed in, click on “Documents and Statements”.

To download the Notice of Variation, Bidder’s Statement and ACCEPT the offer online, scan the barcode to the right with your tablet or visit https://investor.automic.com.au/#/signup on your browser and follow these instructions:

1. Click “Register” then select "Metallica Minerals Takeover Offer" from the dropdown list in the Issuer Name Field

2. Enter your Holder Identification Number / Holder Reference (HIN/SRN)

3. Enter your postcode OR country of residence (only if outside Australia)

4. Tick the box "I'm not a robot" and then select "Next"

5. Complete the prompts to set up your username and password details

6. Once you are logged in, select “Offers” from the left-hand vertical menu and follow the prompts.

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ENQUIRIES

If you have any queries about the terms of the Offer or how to accept, please call the Metallica Offer Information Line (Monday to Friday, between 8.30am (Sydney time) and 5.00pm (Perth time) on 1300 636 752 (within Australia) and +61 2 8318 7933 (outside Australia).

Tuan Do Company Secretary Diatreme Resources Limited