Dateline Resources has kicked off a major geophysical and geochemical survey blitz at its Colosseum gold-rare earths project in California to unlock a potential dual play from one of America’s most geologically prospective corridors.
The company has launched a high-tech magnetotelluric (MT) study across the project to collect detailed imaging data from beneath the surface and spot hidden breccia pipes and other geological anomalies that might be laden with rare earths and gold.
MT surveys use fluctuations in the earth’s natural electrical and magnetic fields originating from solar winds and lightning storms to measure variations in electrical conductivity.
The fabled Mountain Pass mine, which is America’s only rare earths project, sits just 10 kilometres south of Colosseum. The data the company has so far collected from the project hints at a clear geological link between the two.
If Dateline can prove up the connection with the current surveys, the Colosseum gold mine could become a prized rare earth project right next to Mountain Pass’s critical minerals processing plant.
Initial groundwork in May picked up geochemical signs of breccia pipes lying just beyond the rim of the mine’s historic pits. To the west and south-west of the old pit, rock chip samples from felsite outcropping – a key marker of gold – also hinted at a broader mineralised system.
The survey is now 70 per cent complete, with data flowing in from 119 of 167 planned MT stations. Early results from the first three lines have produced 2D resistivity cross-sections, revealing intriguing contrasts that may mark important structural features at depth.
A full 3D inversion model is expected in the next four weeks after the survey wraps up. The data will be a critical component of the company’s “stacked evidence” strategy, combining geophysics, gravity, geochemistry and potentially ground magnetics to pinpoint high-confidence drill targets.
Along with the geophysics, Dateline is running a broad geochemical sampling program, which is halfway complete with 599 of 1200 planned samples collected. The company expects to wrap up the program in about three weeks.
First samples have been submitting for full multi-element analysis, which will include a test for the entire suite of rare earth elements. Dateline says it should receive its first assays in July. When it has a full dataset in hand, the company says it will be in a strong position to prioritise its next drill targets, including those for a maiden rare earth-focused program.
Dateline Resources managing director Stephen Baghdadi said: “Each batch of samples sent to the lab and each line of geophysical data brings us a step closer to uncovering the next phase of Colosseum’s potential. Combining these new datasets will allow us to pinpoint the most prospective zones for both gold and rare earths with a high degree of confidence. This systematic approach is laying the groundwork for our upcoming drilling campaigns, including the maiden REE-focused drill program, to unlock value from this unique gold-REE project.”
Dateline says the geophysical and geochemical campaigns have been extremely useful in building up a more complete picture to add to the already strong economic fundamentals at Colosseum.
Last month, the company updated its gold price assumptions from US$2200 to US$2900 per ounce to unveil a 134 per cent improvement in the project’s net present value (NPV) to US$550 million (A$850M) over a payback of just 19 months.
Production is forecast to reach 635,000 ounces of gold over an 8.3-year mine life with annual production averaging 71,000 ounces grading 1.3 grams per tonne (g/t). The project has a blistering gold recovery rate of 92 per cent.
The fully owned Colosseum already hosts an impressive current JORC resource of 27.1 million tonnes grading 1.26g/t for 1.1 million ounces of gold. Almost 70 per cent of the total inventory sits in the higher confidence measured and indicated categories.
As the data rolls in and the company sharpens up its drill targets, Dateline’s California crusade could be on the cusp of unearthing significantly more gold. It could also pick up a bonus rare earth prize to help improve America’s drive to become self-sufficient in critical metals.
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By James Pearson
