Dateline Resources has reported strong step-out results from a diamond drill hole at its wholly owned Colosseum gold-rare earths project in California, which intersected 150m assaying 1.39 grams per tonne (g/t) gold from surface, including a high-grade interval of 55m at 2.83g/t gold.
The hole targeted a northeast extension of the North Pipe breccia system beyond the current mineral resource boundary and ended in mineralisation with about 1g/t gold at the bottom of the hole, confirming the system remains open at depth.
This latest result has added to earlier broad reverse circulation (RC) drill intercepts in the same north-eastward extension and demonstrates continuity of gold mineralisation over hundreds of metres.
Significant previous RC intercepts included a long run of 296m assaying 1.04g/t gold from surface, featuring a 38-metre section going 2.04g/t gold.
A second RC intercept bored through 297m of rock, averaging 0.68g/t gold from surface, containing a 34-metre slice grading 1.25g/t gold, while a third hole pierced a 105m long zone running 1.24g/t gold from surface, including 53m at 1.45g/t gold.
Notably, those broad intercepts – including the most recent result reported - all begin from surface, underlining the scale and accessibility of the system.
Even more compelling, the mineralisation sits outside the existing JORC-compliant resource boundary, which totals 27.1 million tonnes at 1.26g/t gold for 1.1 million ounces of gold, with more than 67 per cent in the combined measured and indicated resource categories.
The latest drilling results continue to support Dateline’s ongoing bankable feasibility study, slated for later in the year.
Dateline Resources managing director Stephen Baghdadi said: “Colosseum continues to deliver positive results as we work systematically across the project. This latest drilling advances our geological understanding and reinforces the view that there is further value to be unlocked beyond those areas already defined.”
Dateline says it has now arranged for new diamond drill rigs with greater depth capability to probe deeper portions of the system below the 300m maximum depth achieved to date. The new rigs will provide continuous core for geological analysis and better definition of the mineralised pipe geometry.
The big-picture aim of the program is to push Colosseum’s life well beyond the 8.5-year open-pit operation outlined in the May 2025 scoping study, which forecast a 61 per cent internal rate of return at US$2,900 (A$4060) per ounce of gold and a net present value of US$550 (A$785) million using a 6.5 per cent discount rate.
With higher-grade zones starting to reveal themselves, such as the 2.83g/t gold interval in the most recent hole, Dateline says the new area mineralisation could potentially support a selective underground mining phase following open pit completion, which would extend production.
Colosseum also contains potential for rare earths potential at depth. The project is located in the Walker Lane geological trend and is only about 10 kilometres north of MP Materials' Mountain Pass rare earths mine in San Bernardino County, California.
Both operations occupy the same alkaline igneous geological corridor and share similar gravity high, magnetic low and resistivity geophysical signatures that spotlight Mountain Pass.
Dateline Resources is steadily advancing Colosseum towards production, and is being rewarded with ongoing drilling success, including high-grade zones from surface and open mineralisation at depth.
Coupled with integrated geophysics targeting deeper potential, strong project economics and a fortified balance sheet, Dateline looks like it is on the right path towards resource growth and prolonged production at its flagship Colosseum project.
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By Doug Bright
