Dart Mining's (ASX: DTM) Unicorn Deposit in northeast Victoria shows similarities to the Urad Climax-type molybdenum deposit at Red Mountain in Colorado, and is the first of its type in Australia, according to a geology review published by the Australian Institute of Geoscientists.
Geological consultant and former Dart Mining director Bernhard Hochwimmer wrote a report detailing the geological setting of Climax style deposits and the key similarities with the Unicorn deposit.
Hochwimmer noted in his review that the Unicorn molybdenum-copper-silver porphyry deposit is the "first Climax-type molybdenum discovery in Australia and heralds a newly emerging molybdenite province within the southeast Lachlan Fold Belt".
"The Climax-type porphyry is one of the rarer types, known mostly from only 13 examples in the North American Cordillera, compared to hundreds of copper porphyries known worldwide.
"Unicorn is therefore of great importance to Australia, and Victoria in particular, by showing the discovery of a Climax-type porphyry is possible outside the North American Cordillera."
According to Hochwimmer, Unicorn also displays one of the most important Climax-type features - stacked mineralisation shells.
Multi pulsed intrusions or multiple cupola intrusions result in vertically stacked ore shells such as at Climax, Mt Emmons and Urad, and can also include laterally compounded intrusive centres, such as at Henderson.
Also highlighted in Hochwimmer's review was the continuing definition of lateral and depth targets at Unicorn.
"Modelling continues to outline lateral and depth targets, analogues to Colorado's high palaeo level Urad deposit, with a potential Henderson like giant depth target which under plated Urad," he wrote.
"A nearby one kilometre diameter concealed depth cluster target near the Unicorn deposit also occurs as the eastern geochemical anomaly."
Dart has begun Resource upgrade drilling at Unicorn with the aim of releasing an updated Resource in the September quarter.
Last year the company reported a higher than expected maiden Indicated and Inferred JORC Resource of 105 million tonnes at 0.07% molybdenum equivalent for the deposit.
However, based on previous drilling results and infill drilling planned these tonnages should increase and allow an Indicated Resource to be estimated to 450 metres depth.
The initial Resource estimated for the Unicorn deposit is interpreted to represent only the upper limits of a very large intrusive porphyry system which has already shown multiple stacked high grade molybdenum zones.
Unicorn is comparable to a style of deposit that typically shows economic mineralisation extending well below 1000 metres depth.