The Golden Cross Mine site is situated eight kilometres northwest of Waihi in the Waitekauri Valley at the base of the Coromandel Peninsula. After producing 20.5 tonnes of gold and 52 tonnes of silver between 1991 and 1998 (worth $NZD430m at 2001 prices) the operation became the first modern mine in New Zealand to successfully move into planned closure and final rehabilitation.

It first operated as an underground gold mine from 1895 to 1920 and had produced two and half tons of gold in this time.


The Golden Cross Mine is at the end of the Golden Cross Road which heads north from Waikino. Rehabilitation has been so successful here there is little to see, other than the tailings dam, a vegetated open pit a fraction of its former self, and interpretative sign. In 2013 a sinkhole developed to one side of the open pit footprint, and has been fenced as a public safety measure.

Gold was discovered here by the Lowrie brothers around 1892, and the site was taken over by the Golden Cross Gold Mining Company in 1893. They erected a 5 stamp battery, expanded to 10 stamps in 1894 with a cyanide plant. This was replaced when the Waitekauri Gold Mining Company constructed a tramway to take the ore to its battery from 1895, 5 kilometres south to Waitekauri. There were very rich crushings in the early days, however the ore went to no depth. This was from the Golden Cross No. 1 Reef. Mining ceased around 1920.

Exploration in 1986, found an extension of the reef, called Empire, offset to the north. An open pit is on a shallow quartz stock work, and underground mine on the Empire vein system, and was developed by Coeur New Zealand Limited (80%), and Viking Mining Company (20%) from 1991. Mining was conducted under contract to Doug Hood Limited, who also undertook the rehabilitation work. Production figures found for this later period are variable, ie. 584 000 ounces Au and 1 675 000 ounces Ag from 5 Mt ore (infomine website PDF), or 662 000 oz Au from 5 136 300 tonnes of ore, and a combined historic and later period of 750 000 oz Au and 2 325 000 Ag (Simpson et.al, 2001).

The mine closed in 1998 due to low gold prices, and a land slip under the tailings dam, leading to its imminent demise, and forcing the company to spend $30 million dollars rectifying. Information found varies from an environmental catastrophe of the dam if an earthquake occurs, to one of the best mine rehabilitation engineering feats in New Zealand, depending in part on the author's world view. The URS study in the reference states there is little likelihood of the dam collapsing.

The deposit is hosted by the Waipupu Formation of pyroxene andesitic lava flows, volcanic breccia, lithic crystal tuff, and minor epiclastic sedimentary rocks. The andesitic lava flows contain phenocrysts of plagioclase, augite, and hypersthene, in a groundmass of plagioclase laths, Fe-Ti oxides, and interstitial glass. This forms the Hanging Wall of the Empire Fault in the mine.

The Waiharakeke Dacite is dacitic lava flows, tuff breccia, minor lithic crystal tuff, ignimbrite, and flow banded rhyolites. Mineralisation of the dacite is similar to the Waipupu Formation with the addition of hornblende. The Whakamoehau Andesite overlies the other two, consisting of andesite and dacite lava flows, and a similar mineralisation to the above two units.

There are five quartz veins in the area. The Hippo vein is just north of the open pit footprint, the Empire vein under the eastern side of the pit, and the Golden Cross No. 1, Empire South, and Tramway veins progressively south. The Empire vein occupies the Empire reverse fault, with the Western Boundary Fault at the western limit of the open pit. The West Mine and Pillar-Beefeater faults run parallel.

Most of the gold-silver is found in electrum and acanthite, with minor pyragyrite and tetrahedrite. Base metal sulphides include pyrite, marcasite, chalcopyrite, sphalerite, arsenopyrite and galena. Most ore is found in crustiform and colloform banded quartz veins. The main Empire Hanging Wall vein dips 65 degrees west, and trends north north-east. The Footwall veins to the east dip west up to 50 degrees, and at depth west 70-80 degrees. The near surface quartz stock work dips steeply north-west or south-east, and the veins are 10-20 cms wide.

The shallow veins of quartz are cryptocrystalline, while deeper in the Empire system are colloform banded. Cavities in the quartz are rimmed by comb quartz, and filled with chlorite, and rarely illite, pyrite and late calcite.

Adularia forms a wedged shaped zone, as an alteration of plagioclase phenocrysts, commonly filling open spaces within quartz veins, and may form 0.05 mm euhedral rhombic crystals.

Chlorite is 5-20% volume of the rock, as an alteration of hyperthene, augite, amphibole phenocrysts, and is found in the groundmass intergrown with quartz. It fills cavities, and forms veinlets, up to radiating masses. The veinlets are cut by late stage calcite.

Pyrite is the most abundant sulphide, found in veins, breccia, and altered country rock up to hundreds of metres from the quartz veins. It rims kaolinite veins, and is found in crystal clusters in kaolinite at depth. Pyritohedra and anhedral pyrite occurs with high Au grades, and cubic pyrite with low Au grades.

Marcasite is the second most abundant sulphide, and is found in similar circumstances as pyrite, except only tens of metres from the quartz veins, and as monomineralic veinlets cross cutting quartz vein stock works.

Titanite and leucoxene is widespread but less than 1% of rock volume as dissemination in the groundmass.

Illite and smectite is widespread flooding the groundmass, filling open cavities, and as veinlets. It also forms a discontinuous covering over the vein system. Illite dominates over smectite near the veins.

Calcite is late, massive, and barren veins, and as a common replacement mineral, especially at depth. It floods the groundmass, and forms veinlets to 5 mms wide cutting colloform quartz veins. At shallow levels the veins are rimmed by platy calcite with interlocking blades to 4 cms long, encrusted by fine grained quartz.

Siderite is found in localised areas, as late stage monomineralic 2 mm wide veinlets, as irregular rims on calcite filled cavities, and spaces within plagioclase and pyroxene phenocrysts.

Kaolinite is widespread, filling veinlets and fractures down to a depth of 400 metres from the surface. At shallow levels these may be rimmed by pyrite, and at depth containing instead clusters of anhedral to cubic pyrite. It is also found as 1 mm wide bands in colloform quartz in the Empire vein system.

Other Regions, Features and Areas containing this locality

References