One ASX stock is catching the eye with a very strong gain on Monday.

In fact, its shares were up as much as 75% to a 52-week high at one point today.

Which ASX stock?

The stock in question is Dateline Resources Ltd (ASX: DTR).

It is a North America-focused mining and exploration company. Dateline owns 100% of the Colosseum Gold-Rare Earth Element (REE) Project in California.

At the time of writing, its shares are up 50% to 14.5 cents.

The catalyst for this has been the release of recent exploration results from the Colosseum project.

According to the release, recent fieldwork and data reviews have significantly expanded the geological understanding of the Colosseum deposit.

It notes that re-examination of existing 2023 gravity survey data, considering recent geochemical findings, confirms that gravity low anomalies coincide with known breccia pipes and newly discovered felsite outcrops around the Colosseum pits. This correlation strengthens the exploration model and target confidence.

Furthermore, geological mapping has identified new felsite dykes 200–900 metres west and southwest of the historic open pits. Management believes that this mapping supports an updated geological interpretation, suggesting the two known pipes are part of a larger cluster.

Importantly, the presence of additional, intact gold-bearing breccia pipes beyond the mined areas is now considered highly prospective. Commenting on the news, the company stated:

In essence, the Colosseum deposit is now interpreted as a large, zoned breccia pipe complex. The two mined pipes may be just part of this complex, likely the most exposed and eroded tops of the system, while additional pipe structures could be preserved nearby.

In the updated model, the breccia pipes are envisioned to cluster in a broader area around the intrusion, potentially extending at depth and along strike beyond the pit confines. These potential pipes could be "intact" gold-bearing breccia bodies that offer compelling targets for discovery of new gold mineral resources.

What's next?

The ASX stock revealed that a multi-pronged exploration program is being launched to "stack the evidence" from geology, geochemistry, and geophysics for drill targeting.

In addition, a grid-based soil and rock sampling program will commence in mid-June 2025, spanning approximately four weeks.

It has also engaged a geophysics firm to complete a magnetotelluric survey to aid in drillhole targeting.

Finally, the company is finalising the design of a dedicated rare earths drilling program and will subsequently factor in additional evidence collected from the geochemistry and geophysics program.