Independent 3D Geophysical Review Ranks Drill Targets at Colosseum

Ranking of Targets Advances Colosseum Gold-REE Project

SAN BERNARDINO, CA / ACCESS Newswire / October 20, 2025 / Dateline Resources Limited (ASX:DTR)(OTCQB:DTREF)(FSE:YE1) (Dateline or the Company) is pleased to announce the completion of an independent geophysical assessment of the Colosseum Project in California, which has refined the ranking of six previously identified breccia pipe gold targets¹. The review, conducted by Dr. Kate Selway (Vox Geophysics), integrated a 3D magneto-telluric (MT) survey with detailed gravity data to evaluate each target’s resistivity and density anomalies. All six targets exhibit the coincident low-density (gravity low) and low-resistivity signatures characteristic of the known gold-bearing breccia pipes at Colosseum. Based on the strength, depth extent, and clarity of these geophysical anomalies, the targets have been ranked to guide upcoming drilling, with Target 1 emerging as the most robust prospect.

¹ASX Announcement 19 August 2025 – Six new gold breccia pipe targets art Colosseum

Highlights

• Target 1 – Highest Ranked Anomaly:Located just to the west of the current breccia pipes, Target 1 was identified as the strongest gold target due to a well-defined coincident gravity low and low-resistivity anomaly extending several hundred metres deep. Dr. Selway described Target 1 as “the most robust target” of the six.

• Target 5 – Extensive Anomaly:Target 5 features the most extensive conductive (low-resistivity) zone (<500 Ω·m) in the survey, co-located with a broad gravity low. This anomaly continues to ~900m depth, highlighting significant vertical potential and ranking Target 5 among the top drill priorities.

• Target 6 – Strong “Bullseye” Anomaly:Target 6 is a distinct 300m x 300m “bullseye” anomaly with a coincident surface gravity low and underlying resistivity low. Both signals show excellent continuity to ~700m depth. Dr. Selway noted the density and resistivity anomalies at 6 are closely co-located, enhancing confidence in this target’s prospectivity.

• Targets 2, 3, and 4:Collectively exhibit encouraging geophysical anomalies (coincident gravity lows and low-resistivity zones) indicative of potential breccia pipe systems, making them promising targets for further exploration.

• Data-Driven Exploration:The prioritisation by Dr. Selway reinforces Dateline’s exploration model by focusing on targets with the clearest coincident geophysical anomalies. All six targets will be further refined with the planned IP survey. This systematic approach is aimed at maximizing discovery success and expanding Colosseum’s 1.1 Moz gold mineral resource base.

Dateline’s Managing Director, Mr. Stephen Baghdadi, welcomed the independent findings, stating:“It is extremely encouraging to have targets ranked by someone of Dr. Selway’s calibre. This independent review not only boosts our confidence in the targets’ geological significance but also helps sharpen our drill prioritisation. As we close out the current infill drilling that is required for our feasibility study, we will immediately focus on the highest-ranking anomalies in the upcoming drill program, aiming to unlock Colosseum’s greater gold potential and continue building value for our shareholders.”

Geophysical Target Assessment and Ranking

Target 1 – West of South Pit (Top Rank):Approximately 250m by 250m in area, Target 1 lies west of the South Pit and is characterized by a strong overlapping gravity low and MT resistivity low. The geology in this area is interpreted to be dominated by felsite intrusives. Dr. Selway’s review highlighted a pronounced low-density anomaly situated between two low-resistivity zones (each <500 Ω·m) that persist a few hundred metres below surface. This well-aligned density and conductivity signature mirrors that of the known Colosseum breccia pipes and elevates Target 1 as the highest-ranked drill target. Dr. Selway described Target 1 as “the most robust target.”

Target 5 – Southwestern Anomaly (High Rank):Target 5 is one of the largest and most intriguing targets defined by the survey. Spanning roughly 500m by 300m in the southwestern part of the tenement, Target 5 is marked by a broad gravity low coincident with a substantial low-resistivity anomaly. Notably, Target 5’s resistivity low is the most extensive in the entire survey area, persisting from near surface to the maximum modelled depth of approximately 900m. Dr. Selway reported a clear co-location of the density and resistivity anomalies at Target 5, with resistivity values below 500 Ω·m – a strong conductive signature that could indicate alteration and mineralisation. This large vertical continuity suggests an extensive breccia pipe or a related structural zone. Target 5 stands out as a compelling target due to the strength and size of its coincident anomalies. It ranks among the top priorities for drilling, as confirming a mineralised system at Target 5 could significantly expand the scale of the Colosseum project’s gold endowment. The planned drilling program will aim to test the core of this deep conductive zone.

Target 6 – Strong “Bullseye” (High Rank):Target 6 is a distinct circular anomaly (~300m by 300m) located south of the existing mineral resource area. It presents as a classic “bullseye” geophysical target, with a well-defined gravity low at surface directly above a low-resistivity MT anomaly. Both the density and resistivity lows at Target 6 show strong continuity down to roughly 700m depth, indicating substantial vertical extent. Dr. Selway’s analysis highlighted that Target 6’s gravity and resistivity anomalies are more closely co-located (overlapping in space) compared to some other targets. This tight overlap of low-density and low-resistivity signals is exactly the geophysical signature expected of a breccia pipe-hosted gold system, increasing confidence in Target 6’s prospectivity. Given its favourable “bullseye” signature and significant depth potential, Target 6 will be a key candidate for early drill testing. Success at Target 6 would reinforce the interpretation that multiple pipe-like structures remain undiscovered within 1.5 km of the known Colosseum orebodies.

Other Targets

Targets 2, 3 and 4 are deemed to be secondary targets to be followed up after drilling the higher ranked targets.

Target 2 – East of North Pit:Target 2 is a gravity low anomaly directly east of the North Pit, occurring over a zone of extremely low resistivity. In fact, the MT response at Targets 2 and 3 includes the lowest resistivity values recorded in the survey. This suggests a highly conductive zone at depth potentially linking Targets 2 and 3.

Target 3 – East of North Pit:Adjacent to Target 2, Target 3 covers part of the same broad low-resistivity zone and spans roughly 200-300m in extent. Together, Targets 2 and 3 appear as distinct gravity lows sitting above a shared conductive zone, possibly indicating they are connected at depth. The MT anomaly at Target 3 is also relatively low in and coincides with a gravity low. Dr. Selway observed that at Target 3, the two anomalies are adjacent rather than perfectly co-located. This spatial offset means the density low and resistivity low do not overlap entirely, which could imply a more complex geology. Despite this, Target 3’s sizeable low-resistivity area (the most pronounced in the survey, shared with Target 2) makes it a plausible breccia pipe candidate. Both Target 2 and Target 3 will benefit from further validation. Drilling at Target 3 will likely be considered after the top targets, or in conjunction with Target 2, to test the potential of this conductive zone to host gold mineralisation.

Target 4 – South of South Pit:Target 4 is an elongate, northwest-trending anomaly (~400m by 300m) situated south of the South Pit. It exhibits a coincident gravity low and resistivity low signature that is strongest near surface but appears to dissipate around 200m depth. This shallower geophysical expression suggested Target 4 might represent a relatively shallow breccia pipe.

Path Forward

With two rigs already drilling on site, and a third rig being set up to commence drilling, Dateline is now planning to systematically test the highest-ranked gold targets alongside the project’s rare earth element (REE) targets. The top ranked gold and REE targets are slated for initial drillholes, aimed at intercepting the interpreted structures at depth. Other targets will likely be addressed at a later stage. This phased strategy balances immediate high-impact exploration with prudent risk management.

The Company remains positive that the refined targeting and prioritisation will translate into new discoveries and mineral resource growth. Further updates will be provided as drilling progresses and additional data become available.

This ASX announcement has been authorised for release by the Board of Dateline Resources Limited.

For more information, please contact:

Stephen Baghdadi Managing Director +61 2 9375 2353 www.datelineresources.com.au

Andrew Rowell Corporate & Investor Relations Manager +61 400 466 226 a.rowell@dtraux.com

Follow Dateline on socials:		@Dateline_DTR @dateline_resources dateline-resources

About Dateline Resources Limited

Dateline Resources Limited (ASX: DTR, OTCQB: DTREF, FSE: YE1) is an Australian company focused on mining and exploration in North America. The Company owns 100% of the Colosseum Gold-REE Project in California.

The Colosseum Gold Mine is located in the Walker Lane Trend in East San Bernardino County, California. On 6 June 2024, the Company announced to the ASX that the Colosseum Gold mine has a JORC-2012 compliant Mineral Resource estimate of 27.1Mt @ 1.26g/t Au for 1.1Moz. Of the total Mineral Resource, 455koz @ 1.47/t Au (41%) are classified as Measured, 281koz @1.21g/t Au (26%) as Indicated and 364koz @ 1.10g/t Au (33%) as Inferred.

On 23 May 2025, Dateline announced that updated economics for the Colosseum Gold Project generated an NPV_6.5 of US$550 million and an IRR of 61% using a gold price of US$2,900/oz.

The Colosseum is located less than 10km north of the Mountain Pass Rare Earth mine. Planning has commenced on drill testing the REE potential at Colosseum.

Dateline has also acquired the high-grade Argos Strontium Project, also located in San Bernadino County, California. Argos is reportedly the largest strontium deposit in the U.S. with previous celestite production grading 95%+ SrSO₄.

Forward-Looking Statements

This announcement may contain “forward-looking statements” concerning Dateline Resources that are subject to risks and uncertainties. Generally, the words “will”, “may”, “should”, “continue”, “believes”, “expects”, “intends”, “anticipates” or similar expressions identify forward-looking statements. These forward-looking statements involve risks and uncertainties that could cause actual results to differ materially from those expressed in the forward-looking statements. Many of these risks and uncertainties relate to factors that are beyond Dateline Resources’ ability to control or estimate precisely, such as future market conditions, changes in regulatory environment and the behaviour of other market participants. Dateline Resources cannot give any assurance that such forward-looking statements will prove to have been correct. The reader is cautioned not to place undue reliance on these forward-looking statements. Dateline Resources assumes no obligation and does not undertake any obligation to update or revise publicly any of the forward-looking statements set out herein, whether as a result of new information, future events or otherwise, except to the extent legally required.

Competent Person Statement

Sample preparation and any exploration information in this announcement is based upon work reviewed by Mr Greg Hall who is a Chartered Professional of the Australasian Institute of Mining and Metallurgy (CP-IMM). Mr Hall has sufficient experience that is relevant to the style of mineralization and type of deposit under consideration and to the activity which he is undertaking to qualify as a Competent Person as defined in the 2012 Edition of the “Australasian Code for Reporting Exploration Results, Mineral Resources and Ore Reserves” (JORC Code). Mr Hall is a Non-Executive Director of Dateline Resources Limited and consents to the inclusion in the report of the matters based on this information in the form and context in which it appears.

Company Confirmations

The Company confirms it is not aware of any new information or data that materially affects the information included in the announcements dated 23 October 2024 with regard to the Colosseum MRE and 23 May 2025 with regard to Colosseum Project Economics. Similarly, the Company confirms that all material assumptions and technical parameters underpinning the estimates and the forecast financial information referred to in those previous announcements continue to apply and have not materially changed.

View the original press release on ACCESS Newswire