Summary:
The Mt Ida Bottle Creek Gold Project (BCP) comprises 10 separate deposits divided into two regions - Bottle Creek and Mt Ida:
• Bottle Creek region consists of Emu, Southwark, Cascade, VB North, VB and Boags;
• Mt Ida and Quinns project area consists of Tims Find, Shepards Bush, Forrest Belle and Boudie Rat.
The deposits and nearby prospects are located in the Archaean Yilgarn Greenstone Belt of WA, more specifically within the northern portion of the Mount Ida Greenstone Belt, forming the eastern limb of the regional south plunging Copperfield Anticline. The geology comprises Archaean mafic to ultramafic lithologies bounded by granitic intrusions, and the region has been metamorphosed to lower amphibolite facies.
A major shear zone, interpreted to be the Zuleika Shear, intersects the eastern part of the project area.
Much of the project area is covered by colluvial and alluvial deposits, with thickness ranging from <1m to tens of metres.
Gold mineralisation in the area is associated with quartz veining +/- sulphides within sheared ultramafic and mafic units; along the Zuleika Shear, gold is often found in quartz/pyrite lodes which are typically enveloped by tremolite schist, within intensely sheared amphibolites.
The Bottle Creek “Emu Formation” which consists of carbonaceous black shale, graphitic chert, BIF and appears as an interflow sedimentary unit between mafic flows which has since been rotated subvertical during orogenesis and now youngs eastward towards the core of the Kurrajong Anticline. The Bottle Creek gold and silver mineralisation is found close to the contact of two sequences and coincides with a sheared, up to 20m thick, Emu Formation which on the eastern contact is a felsic porphyry unit.
The western contact appears as weathered quartz-biotite schists and mafic volcanics. These schists have been subjected to potash metasomatism, silicification and carbonatisation. At surface the sheared Emu Formation is a gossanous ironstone and has been oxidised and lateritised to a depth of 100m.
Below the base of weathering and oxidation, a massive pyrite-pyrrhotite zone up to 6m thick occurs within the sheared black shale in a variable gangue of quartz and white mica, coarse grained quartz, siliceous graphitic schist, grunerite-chlorite schist, garnet pods and ankerite-calcite-biotitehornblende-quartz schist. Silver occurs within tetrahedrite, arsenical pyrite, pyrrhotite, sphalerite, arsenopyrite, chalcopyrite and electrum within the massive sulphides.
Dimensions
The Bottle Creek mineralised zone has a 10 km strike containing the identified deposits.
Emu South and North Area has been modelled over 1900 m of strike.
Cascade has been modelled over 300m of strike.
Mineralisation has also been modelled between, along strike of and below the VB and Boags pit voids covering approximately 2,200m of strike.
The mineralisation occurs over a 5 to 20 m width and has been identified consistently to 120 m and up to 160m in depth.
The Tim’s Find trend has an approximate1.4 km strike containing the 3 main identified mineralized zones.
The Tim’s Find North Area has been modelled over 160 m of strike.
The Tim’s Find Central Area has been modelled over 400m of strike.
Tim’s Find South has been interpreted as having a strike length of approximately 700m with the main modelled part of this zone having a strike length of 300m.
The mineralisation is observed at widths of 2 to 6m and persistently extending to depths of between 100 m and up to 130m.
Eleven block models were constructed, one for each deposit reported. Strike lengths vary from 100 m to 600 m (Forrest Belle), plan widths between 10 m and 60 m, and depth below surface ranging from 65 m to 200 m.