Jubilee Mine, Waitekauri, Hauraki District, Waikato Region, New Zealandi

Regional Level Types
Jubilee Mine	Mine
Waitekauri	- not defined -
Hauraki District	District
Waikato Region	Region
New Zealand	Country

Gold was discovered here in 1875 by Daniel Leahy (Simpson, 2011). Located immediately west of the old Waitekauri claim. In 1888, the lease was taken over by E. Kersey Cooper, representing an English syndicate. A 10 stamp battery, 5 berdans, and 2 grinding pans were installed, processing loose quartz in the gullies, and near surface pottering on a large quartz blow. It proved unpayable, and work was suspended.

In 1891, work resumed, and an adit was driven, however a dispute arose over who owned the claim. Kersey Cooper won this fight, raised more finance, and continued to drive the adit until work stopped again in 1902. Operations re-started in 1904, but ceased permanently in 1912.

The host rock is the Waipupu Formation pyroxene andesite lava flows, lesser volcanic breccia, localised lithic crystal tuff, and minor epiclastic sedimentary rocks.

The Jubilee is the main quartz vein in the area, historically producing 1292 ounces (assumed gold) from 2118 tonnes of ore (Chook Sutton). (Christie, et. al. 2007, 426 kg Au, 475 kg Ag). It is a single vein at depth, but splays into several narrow veins near the surface. The Jubilee vein is 990 metres long, down to a depth of 215 metres, averaging 2.4 metres wide. It is however lenticular, and narrows in parts to only several centimetres wide.

The quartz is massive to coarsely crystalline, and locally comb, with Au-Ag associated with crustiform banded quartz sections. Much of the vein is sub-economic. Adularia patchily co-exists with some sections of the quartz.

Illite and chlorite is common, while epidote and prehnite is minor. Kaolinite is trace, associated with near surface orange to yellow iron oxyhydroxides in the weathered zone.

Thin pyrite veins occur, with sub-ordinate quartz up to 2 mms wide. The quartz is colourless to milky white, medium to coarse grained massive and crystalline, with comb quartz rimming cavities. Most of the quartz veins contain under 1% pyrite, and sometimes the comb cavities are filled with calcite. Base metal sulphides are chalcopyrite, sphalerite, and galena, with associated gold and silver (possibly electrum), however (Simpson, 2011) sheds little light on metallic ores at the deposit.

(Rabone, 1975) states mineralisation is found in blue-grey quartz, with a seam 2-30 cms wide containing sparsely disseminated base metal sulphides.

Hollow balls of radiating pyrite, Rabone suggests is possibly recrystallised marcasite balls, with chalcopyrite. Pyrite is mainly included within chalcopyrite, rarely galena, and sometimes is intermittently intergrown. The chalcopyrite is coarse grained to 5 mms. Galena is finer grained, forming lattice like areas intergrown with quartz, and rarely intergrown with sphalerite. Coarse grained sphalerite to 10 mms is the most abundant sulphide. Galena veinlets replace sphalerite along fractures.

Supergene covellite is found sporadically as fine grained aggregates replacing chalcopyrite, and rare coarse crystals in sphalerite cracks. Supergene chalcocite replaces galena, that in turn has replaced sphalerite.

Other Regions, Features and Areas containing this locality

References