woods point geology

For educational purposes

Australia's Lachlan Fold Belt in south-eastern Australia was historically the source of most of Australia's gold and because of the relatively high price of gold in aussie dollars, compared with extraction costs, new gold mines are now being developed and others re-opened within this region.

The geology of the region is well known.

The Lachlan Fold Belt is basically mesothermal (of middle-thermal or "secondary" thermal origins). The gold ores are quartz reefs within the volcanic rock or adjacent to (or within) flexible layers of sedimentary rock. The sedimentary rock is clastic: made up of fragments of pre-existing rocks and could be regarded as metamorphosed. This geological structure is characteristic of the entire Lachlan fold belt, which includes Stawell, Ballarat, Bendigo, Castlemaine and Walhalla. The Beechworth and Woods Point goldfields are also within the Lachlan fold belt.

Geological activity such as initial folding, then massive shearing and consequent faulting produced fluid passages within the geological structure. Faults are nearly always secondary or subsidiary to large sheared zones.

Passages through the shear planes and faults provided channels for hydro-thermal fluids containing numerous minerals.

The quartz reefs are created by intruding feldspars (rock forming silicates) which become plutons: igneous rock which solidifies far beneath the surface. Modern theory suggests that quartz reefs develop slowly not suddenly.

Quartz is crystalline and shears at crystal boundaries providing paths for mineral and gold bearing water. The gold, being corrosion resistant, collects within the cracks in the quartz, whereas other metals will not accumulate in this way because they corrode away. Basically quartz reefs are an excellent gold filtering system!

Quartz reefs in the fold belt tend to be nearly vertical and usually have longitudinal continuity, some extending to 2km to 3km beneath the surface, but usually the reefs are discontinuous and contain zones of high and low grade gold.

If there have been major water flows through the faults then the gold-bearing quartz is eroded and becomes the source of alluvial goldfields. There are thousands of placer deposits (alluvial) within the Lachlan fold belt region - mostly exhausted and abandoned by the surface miners.

The geology of the Lachlan fold belt is well understood by geologists and leads to reasonably predictable new discoveries of gold-bearing quartz reefs. The historical placer deposits are reliable indicators of nearby gold-bearing quartz reefs.

I have spent many days investigating the Lachlan fold belt (due diligence via 4-wheel drive and GPS navigation) and spoken with miners and mine managers.

I am holding a diverse portfolio of the listed miners in the Lachlan fold belt region.

Anyone interested in a discussion of the mining companies involved feel free to email me and we can have a discussion of the possibilities.