The Fort Worth Press - Interpretation of High-Resolution Geophysics at Music Valley HREE Project

SAN BERNARDINO, CA / ACCESS Newswire / June 17, 2026 / Dateline Resources Limited (ASX:DTR)(OTCQB:DTREF)(FSE:YE1) (Dateline or the Company) is pleased to announce the geophysical interpretation of the Music Valley Heavy Rare Earth Project (Music Valley), located in Riverside and San Bernardino Counties, California, USA.

Highlights

• Magnetic and Radiometric Processing Completed: Mitre Geophysics has completed processing of the Music Valley HREE Project datasets.

• Favorable Structural Setting: The interpretation highlights numerous structures across the project area, increasing the likelihood for HREE concentration.

• Priority Areas of Interest: Three prospect areas identified for follow up are all located on claims unaffected by the current litigation.

• Mapping Geophysical Targets: Ground truth mapping underway by Dateline's HREE and structural geology consultants to confirm correlation with geophysical anomalies.

The magnetic and radiometric survey undertaken in March 2026 included all the 20,520 acres highlighted in the Music Valley Project announcement (ASX Announcement 11 March 2026).

The geophysical interpretation highlights significant structural detail, corresponding with areas that the USGS has mapped containing the favorable Pinto Gneiss unit. The Thorium rich domains appear to be the best proxy for HREE mineralization, with local faulting and contact with younger diorite intrusions expected to be the most prospective targets for exploration. The coincidence of these three features will be the focus of future mapping, sampling and drilling campaigns.

All three priority prospects are located outside the 252 claims that are the subject of court proceedings.

Dateline's Managing Director, Stephen Baghdadi, commented:

"Music Valley has always had the ingredients of a significant heavy rare earth district. What these surveys have done is show us where those ingredients come together.

"The interpretation has identified a series of structurally complex zones associated with elevated thorium signatures and favorable Pinto Gneiss geology. These are precisely the types of settings where we would expect rare earth mineralization to be concentrated.

"Rather than searching across a large land package, we are now focusing on a small number of highly prospective target areas. Tony Mariano Jr and Russell Mason are currently ground-truthing these prospects, and that work will guide the next phase of sampling and drill targeting."

Survey Interpretation

The most interesting feature was noted with the Th²/U ratio map from the radiometric survey. The high Th is considered a proxy for elevated HREE in the minerals monazite and xenotime. The processed data highlighted a number of structurally complex zones on the western side of the project for further examination. These appear to correlate in some zones where the Pinto Gneiss was mapped at the regional scale.

Figure 1: Th²/U ratio map (Viridis color palette, with 5% standard deviation stretch) developed to show high Thorium concentrations relative to normal granite / granite gneiss (Th/U ~1). The three priority prospects are highlighted.

The interpretation of the magnetic and radiometric surveys highlights two major structural trends, one trending 286^o that is related to the Pinto Mountain Fault and a younger set trending more towards 330^o. The Pinto Mountain Fault is connected to the San Andreas Fault Zone, which is a right lateral system taking up strain from the interaction of the continental US Plate with the Pacific Plate.

Figure 2: Reduced to Pole (RTP) residual total magnetic intensity data, underlain by the Tilt filtered version of this data, with Mitre structural interpretation overlain. The geology denoted as Xp represents the Pinto Gneiss target unit.

The younger 330^o structures are more prevalent and have intensely deformed the older primary fabrics, leading to structural complexity on the ground. This was mapped by the Dateline consultants, who identified a more complex geology than shown in the regional scale mapping.

Commentary

The aerial geophysics surveys confirms that the Music Valley Project area has a number of structures that have the likelihood to concentrate fluids, with near E-W structures connected to and reacting to the San Andreas Fault Zone to the west. Very young transpressional faulting, mostly represented by the more 330^o striking structures, are accommodating rotation around vertical axes. With all this very intense recent deformation, the preservation of much older (Paleoproterozoic) primary fabrics that have not been reactivated and transposed into the present day deformation fabric is unlikely.

The radiometric signature, particularly the Th elevation, shows that there is a strong structural overprint, rather than high radiogenic activity simply being controlled by lithology. This implies that whilst the Pinto Gneiss is the target rock unit, enrichment of REEs is likely to occur in areas of structural faulting where it has been concentrated.

There are three main zones identified for detailed ground truth mapping and sampling follow up. The southern area in the acquired Fermi claims has USGS mapped Pinto Gneiss and anomalous Th, the high Th zones in the NW corner of the project warrant attention and a zone in the southern centre of the project also contains anomalous Th values.

The three priority target zones for follow up are either within the claims acquired from Fermi Critical Minerals or within staked claims that are outside of the claims currently under litigation by US1 Critical Minerals.

Tony Mariano Jr and Russell Mason are currently at Music Valley undertaking ground truth mapping of the three priority prospects. A larger scale rock chip sampling program will be undertaken as part of this campaign. We expect to have further information on these priority prospects in the next two weeks.

This press release has been authorized for release by the Board of Dateline Resources Limited.

For more information, please contact:

Stephen Baghdadi
Managing Director
+61 2 9375 2353

Andrew Rowell
Corporate & Investor Relations Manager
+61 400 466 226
[email protected]
www.datelineresources.com.au

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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 and is located 10km north of Mountain Pass rare earth mine. Drill testing the REE potential at Colosseum has commenced.

On 11 May 2026, Dateline announced that the BFS economics for the Colosseum Gold Project generated a pre-tax NPV₅ of US$785 million and a pre-tax IRR of 49.5% using a gold price of US$4,200/oz.

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.

In March 2026, Dateline consolidated the Music Valley Heavy Rare Earth Project in Riverside and San Bernardino Counties, California. The region has known HREE mineralisation from USGS rock chip sampling, however it has not been subjected to modern exploration techniques.

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 behavior 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.

SOURCE: Dateline Resources Limited

View the original press release on ACCESS Newswire

B.Martinez--TFWP