Camoola Reef (Camoola Mine), Paeroa, Hauraki District, Waikato Region, North Island, New Zealand
|Latitude & Longitude (WGS84):||37° 16' 59'' South , 175° 45' 59'' East|
|Latitude & Longitude (decimal):||-37.28333,175.76666|
|Köppen climate type:||Cfb : Temperate oceanic climate|
The vein is 915 metres long, dips 65 degrees west, averages 6.1 metres wide.
There are three distinct lenses, with three levels of workings. Each lense is about 12 metres wide, narrows north and south, and tapers at depth. The lenses are described as cavernous quartzose replacement after calcite, with bands of massive quartz and sheets of silicified propylite, stained in the upper levels with iron and manganese oxides . The northern lense is linked to the central lense by vein material, although displaced by two south dipping reverse faults. The central lense is linked to the southern lense by a shear zone, displaced by four reverse faults. Each lense contains similar geology.
The ore is mainly disseminated in irregular sheets of carbonate, or occur as thin bands in this material. Most veins in the lenses are un-mineralised.
Strong mineralisation occurred in a fan shaped section of the reef, containing galena, sphalerite, chalcopyrite, pyrite, aguilarite, electrum, native silver as the primary ore minerals. Some free gold is found in the upper oxidised areas of the reef in carbonate gangue. There is little secondary mineralisation. Ore mineralisation occurs as patches and very fine 'shreds' disseminated through the quartz-carbonate veins. Rhodochrosite and siderite gangue is also noted.
The reef was the third location discovered in the world for the rare sulpho-selenide aguilarite in 1972, although it has since been found in many other places, including six within this region. It occurs as clusters of minute anhedral crystals associated with the other ore minerals mentioned above, in a quartz-carbonate matrix. It rarely exceeds 0.05% volume of the rock
Little was found for the late 19th Century period, but the patchy and low grade nature for most of the reef may have limited development. Along with several other deposits nearby, the site was a focus for the Ohinemuri Gold and Silver Mines Company (1914-1930), however low silver prices forced a cessation of operations. In the late 1970's, the Consolidated Silver Mining Company of New Zealand Limited, or Consilver extracted gold and silver from the Camoola quartz veins.
18 valid minerals.
This geological map and associated information on rock units at or nearby to the coordinates given for this locality is based on relatively small scale geological maps provided by various national Geological Surveys. This does not necessarily represent the complete geology at this locality but it gives a background for the region in which it is found.
Click on geological units on the map for more information. Click here to view full-screen map on Macrostrat.org
0 - 2.588 Ma
|Cenozoic volcanic rocks|
Age: Pleistocene (0 - 2.588 Ma)
Reference: Chorlton, L.B. Generalized geology of the world: bedrock domains and major faults in GIS format: a small-scale world geology map with an extended geological attribute database. doi: 10.4095/223767. Geological Survey of Canada, Open File 5529. 
|Pliocene - Late Miocene|
2.588 - 11.62 Ma
|Whitianga Group rhyolite lava and related deposits|
Age: Neogene (2.588 - 11.62 Ma)
Stratigraphic Name: Whitianga Group
Comments: Zealandia Megasequence Extrusive and Intrusive Rocks (Neogene)
Reference: Edbrooke, S.W., Heron, D.W., Forsyth, P.J., Jongens, R. (compilers). Geology Map of New Zealand 1:1 000 000. GNS Science Geological Map 2. 
|Messinian - Tortonian|
5.333 - 11.62 Ma
|Waiwawa Subgroup andesite and dacite (Coromandel Group) of Coromandel Volcanic Zone|
Age: Miocene (5.333 - 11.62 Ma)
Stratigraphic Name: Waiwawa Subgroup
Reference: Heron, D.W. . Geology Map of New Zealand 1:250 000. GNS Science Geological Map 1.