Sampling and analysis work begins at the Colossus rare earth ore mine

According to a report from Mining.com, Dateline Resources has commenced geological engineering sampling work at its Colosseum gold-rare earth project in San Bernardino County, California, with the aim of delineating targets for future drilling.

The Australian exploration company stated in a press release issued last week that its field team is systematically collecting approximately 1,200 samples across the entire project area, starting with the highest priority targets identified through recent geological mapping and gravity surveys.

The company said that all samples will undergo full-element laboratory analysis (including all rare earth elements) to delineate geochemical anomalies and tracer elements. The results will be used to create detailed geochemical maps and identify gold or rare earth targets for subsequent drilling.

Although preliminary results may be available as early as July, they cannot be analyzed until all data has been compiled.

In addition, the company's team will conduct a magnetotelluric (MT) survey during the later stages of soil sampling to visualize the geological structure of the Colosseum deposit. The company may also utilize ground magnetic surveys to support the MT investigation.

At the right time

The exploration of the Colosseum project coincides with a period of heightened interest in gold and rare earths.

Gold, amidst frequent market fluctuations, has emerged as one of the best-performing commodities this year, reaching a new high of $3,500 per ounce in April. Rare earths have also become a focal point in the tariff war.

For decades, the US has relied on imports for its rare earth needs. Currently, the country has only one operating rare earth mine, Mountain Pass, located approximately 10 kilometers south of Colosseum.

The Colosseum project has a history of gold mining dating back to the California Gold Rush era. Large-scale gold mining at the mine began in the 1980s, owned by LAC Minerals of Canada. Before the mine's closure in 1993, two open pits produced a total of 344,000 ounces of gold. Since then, there has been little mining activity at the site, and its rare earth potential remains unexplored.

"During the mine's last operation, the gold price was less than $350 per ounce, and there were few incentives to conduct subsequent exploration for cryptoexplosive breccia. During that period, rare earth elements were not a priority, so the significance of Colosseum's rare earths was only recently recognized," explained Stephen Baghdadi, the company's manager.

"Now, the environment has changed dramatically, with rising gold prices and strong strategic demand for rare earths, necessitating systematic field investigations into Colosseum's potential," he added.

The company stated that its current exploration program is crucial for unlocking the dual potential of gold and rare earths. Any meaningful anomalies or targets delineated through soil sampling and MT surveys will serve as the basis for the next drilling program. Currently, the company has preliminarily completed a rare earth-focused drilling program.

DOI support

Colossus recently received public support from the US Department of the Interior (DOI), as it has the potential to become the second rare earth mine in the US.

Earlier this month, Interior Secretary Doug Burgum stated in an interview with Fox News that the restart of the Colossus Mountain project in California is a "critical step" in expanding the US's supply of critical minerals.

The company's team has concluded from its review of historical data that Colossus shares a similar geological setting to Mountain Pass. Mountain Pass commenced production in 1952 and was the world's primary source of rare earths from the 1960s to the 1990s.

Currently, the project does not have an estimated rare earth resource, but it does have a JORC-2012 compliant gold resource of 1.1 million ounces, with approximately two-thirds classified as measured and indicated. A scoping study conducted in August 2024 estimated a mine life of over 8 years, with an average annual gold production of 75,000 ounces.