Will the Star rise again?
Virtually all of Victoria’s historic goldfields are receiving exploration attention encouraged by the rise in the gold price and relatively good access to speculative or risk capital.
Among the sites experiencing renewed activity is the Morning Star mine at Woods Point, in isolated mountain country 120km north east of Melbourne.
Mount Conqueror Minerals, which has held the mine area under licence for a decade or so, has launched a significant effort to gain underground access by reclaiming the main shaft.
The company recently adopted Morning Star Gold as its new name.
The enthusiasm for the Morning Star is understandable.
From its discovery in 1861 until it closed in 1963, the mine produced at least 27.4t of gold at a published recovered grade of 24.5g/t, while the battery tailings contained between 2g/t and 6g/t.
Gold Mines of Australia, the eastern gold mining division of then WMC, mostly mined the operation from the 1940s through to closure.
A geological survey of the last phase of mining prepared in the mid 1990s shows convincingly that the Star closed down for reasons other than lack of gold.
For instance, there are more than 600 auriferous drill hole intersections identified within the mine area, which extends from surface to 24 level at about 1100m depth, that were never followed up.
It was traditional to develop every second or third level and production would be sourced by underhand stoping off winzes or rising off sub-levels.
Extensive manual handling of ore led to high mining costs. For instance, some ore was hand shovelled eight times before it got to surface!
Encouraged by the wealth of historical data, Morning Star Gold is dewatering, hiring staff and has secured the 6 level at about 185m below surface.
Mmine manager Ray Wright says he has a team of five local miners engaged on the shaft recovery works and is expecting to gain access down to the 9 level (at about 500m) by April.
The zones above 5 level were very rich, often 40g/t and were not always mined out.
Moreover, some zones were filled with “low grade material” averaging 7g/t to 8g/t.
The principal target of the shaft rehabilitation program is to test a zone known as “the gap”, which is repetitions of the ladder vein stockwork system between the 200m and 600m section of the mine, which was neither intensively explored nor mined historically.
A 2005 geological depth/strike model proposed targets of greater than 4Moz below the 200m level. The rehabilitation of the main shaft in addition to sampling extensions to the known mineralised systems will create underground diamond drilling platforms to test the gap zone.
The Morning Star dyke is a substantial structure, mined down to 1100m with a strike length of 750m. The dyke zone measures between 60m and 115m in width.
Historically the mine was worked from surface to 50m, from 120m to 230m and from 500m to 700m. The effective mining zone was only 360m out of the 1100m drilled depth with this section producing up to 5000oz Au/m.
Some drill holes historically produced only low gold values, yet mining adjacent to them revealed visible and payable gold.
30-Mar-2006