Daisy-Milano Gold Mine (Daisy-Milano Complex), Mount Monger, Mount Monger Goldfield, Kalgoorlie-Boulder Shire, Western Australia, Australiai

Regional Level Types
Daisy-Milano Gold Mine (Daisy-Milano Complex)	Mine (Active)
Mount Monger	Mountain
Mount Monger Goldfield	Ore Field
Kalgoorlie-Boulder Shire	Shire
Western Australia	State
Australia	Country

The mine is 50 kilometres south-east of Kalgoorlie. Daisy-Milano is an underground mine accessed via a portal just south of the Mount Monger pastoral station homestead. The Daisy-Milano Complex refers to the geology in the immediate area.

Gold was discovered here in 1896, and several small companies mined the area for 400 000 oz of gold from the old workings to 80 metres depth. Alot of historic information was found in the 1930's and 1940's, when the field appeared to be particularly active, with several companies and small syndicates working it.

At this time Daisy and New Milano were major mines on the field, along with nearby Christmas Flat, which were to be later consolidated into one mine. Ore was accessed via shafts. The mine manager of Daisy in the 1940's was W Lydiate, and New Milano Bill King and Latham Watson.

The latest mining operations started in 1990 by Ridgeview Nominees Pty Ltd, who sold it to Perilya Limited in January 2005 for 3.2 million(Australian). They had no local processing facility, and the cost of transport caused them to close the mine and sell it to Silver Lake Resources in November 2007 for 14.5 million (Australian). They re-opened the mine, but reverted the mining back to hand held methods. This was because the gold mineralisation is contained in a swarm of quartz veins ranging from a few mms to several cms, and is not suitable for mechanical methods. The underground mine is accessed via a decline, and the ore was initially processed at the Lakewood facility 5 kilometres south-east of Kalgoorlie. Later the company merged with Integra Mining, which gave its access to the nearby Randalls mill.

The mine accesses several named lodes both under Daisy-Milano, and neighbouring historic mines. These lodes include Daisy-Milano, Rosemary, Haoma, Haoma West, Stanley, Christmas Flats, and Dinnie Reggio. The latter two were mined as open pits as well, and will be listed separately. Mining commenced on the Rosemary lode Level 6 in December 2007, Haoma ore from level 3, 2 June 2011, Haoma West and the Lower prospect was later brought into production.

The host rocks are intermediate to felsic volcanic rocks, located to the north-east, and plunging south beneath an overlying north-west trending ultramafic unit 250 metres thick. The host sequence is intruded by quartz-feldspar porphyry, as well as several east-west trending Proterozoic mafic dolerite intrusive dykes from a few centimetres to several metres thick.

There are two suites of porphyry cross-cutting the mine host sequence. One called Green Porphyry, 2 to 30 metres wide, a feldspar-quartz phyric sill. The second is a suite of grandiorite porphyry of coarse feldspar phyric and hematite alteration. The Red Porphyry cross-cuts the Green Porphyry and mineralisation in the mine.

There are two dominant fault zones called North and South, and a recently discovered third named Caledonian. These are north-west striking, dipping approximately 50 degrees south-west, being 0.5 to 1 metre wide zones of clay and rubble, with up to 2 metres of sheared margins.

The gold is hosted in 5 cm to 1 metre quartz veins in porphyry/andesite host rock. The veins are found in a dilational zone within a north-south trending shear zone. The quartz veins contain abundant free gold, sphalerite, and galena. Veins are most common on the contact between the Green Porphyry and volcaniclastic host sequence. Some ore veins step through the Green Porphyry, linking the Hanging Wall and Footwall lodes. The highly sericite altered veins trend north-south, with a steep dip, while veins in the porphyry trend north north-west.

The highest grade of gold is found at the intersection of the contacts and veining, over lengths of 25 metres. The mineralisation is overprinted by late stage quartz-carbonate-schorl north-west to south-east trending extension veins outside the porphyry, showing no gold.

New discoveries continue. At the time of writing a new major fault had been uncovered named the Caledonian Fault, and accompanying Sasha Lode with gold bearing ptygmatic (squiggly) quartz veins.

Many gold mines in Western Australia have been developed to such a point, ore is processed with no visible gold to the naked eye. Gold at Daisy-Milano is highly visible and nuggetty. They would make fine specimens in the collectors market, especially for those who consider location details important, which is often lacking with nuggets found with hobby metal detectors. It is unlikely they will be sold separately, as it would be seen as a nuisance to the company, when processing large volumes of ore.

Other Regions, Features and Areas containing this locality

References