Project Summaries

Lachlan Fold Belt

Mount Read Volcanics Belt

Mount Read Volcanics Belt Projects, Tasmania


Geological and Metallogenic Setting of northwest Tasmania

The northwest Tasmania joint venture project with Bass Metals Limited includes twelve Exploration Licences (ELs) covering a total area of 732 km2 of the Mount Read Volcanic Belt. The JV includes the North Rosebery, Leven River - Loyetea, Lynchford, Highclere, Waratah, Oonah and Whyte River Projects as detailed within Section 5. Bass is entitled to retain its 75% interest in the tenements by sole funding Clancy to prefeasibility study stage.

The Cambrian aged Mount Read Volcanic Belt (MRV) forms a 200 x 20km north-northeast trending belt of dominantly calc-alkaline volcanics and volcaniclastics (Corbett 1992). The volcanics were erupted along the western margin of a Precambrian block, now referred to as the Tyennan Block of central Tasmania and comprised a lower eastern zone of massive lava-rich sequences and a western zone dominated by volcano-sedimentary and volcaniclastic units and breccias. Stratigraphic and facies relationships are complex but considerable mapping has been undertaken by numerous organisations in attempts to define prospective horizons favourable for mineralisation. 

 

Following previous workers, Clancy (Core et al, 2006) subdivided the lower portion of the MRV into the Central Volcanic Complex, the eastern quartz-porphyritic sequence and the western volcano-sedimentary sequence all of which are unconformably overlain by the felsic units of the Tyndall Group. As well as complex stratigraphic relations, these units are disrupted by several major faults including the prominent Henty, Great Lyell and Rosebery Faults and intruded by dolerites, quartz-feldspar porphyries and several large, Devonian aged granitoids.

The MRV is well mineralised hosting several significant base metal deposits including Mt Lyell, Rosebery, Renison, Mt Bischoff, Que River and Hellyer in addition to the Henty gold deposit. The felsic Central Volcanic Complex hosts VHMS mineralisation at Mt Lyell, Hercules and Rosebery while Que and Hellyer are located within the Mt Charter Group of the Western volcano-sedimentary sequence. Recognising that the Mount Read Volcanic Belt is one of the most highly and variably mineralised rock units in the world (Corbett 1992), targeting by Clancy has also incorporated models for intrusion-associated tin (for example Renison, Mt Bischoff) and nickel deposits (for example Avebury) as well as for orogenic gold deposits. Note that despite there being no known examples of orogenic old deposits in Tasmania, the presence of placer and lode gold deposits as well as potentially favourable Precambrian stratigraphy indicate the right model elements are present.