Pink and White Terraces
| Pink and White Terraces | |
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Blomfield: The White Terraces (1884)
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| Location |
 New ZealandBay of Plenty |
| Coordinates | 38°15′38″S 176°25′50″E / 38.260556°S 176.430556°ECoordinates: 38°15′38″S 176°25′50″E / 38.260556°S 176.430556°E |
| Spring source | Okataina |
| Type | Hot spring |
 Location of the Terraces in New Zealand
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The Pink Terrace, or Te Otukapuarangi ("The fountain of the clouded sky") in Māori, and the White Terrace, also known as Te Tarata ("the tattooed rock"), were natural wonders of New Zealand. They were reportedly the largest silica sinter deposits on earth. Until recently, they were lost and thought destroyed in the 1886 eruption of Mount Tarawera, while new hydrothermal attractions formed to the south-west i.e. Waimangu Volcanic Rift Valley.
The Pink and White Terraces were formed by upwelling geothermal springs containing a cocktail of silica-saturated, near-neutral pH chloride water. These two world-famous springs were part of a group of hot springs and geysers, chiefly along an easterly ridge this year named Pinnacle Ridge (or the Steaming Ranges by Mundy). The main tourist attractions included Ngahapu, Ruakiwi, Te Tekapo, Waikanapanapa, Whatapoho, Ngawana, Koingo and Whakaehu.
The Pink and the White Terrace springs were ~1200 meters apart. The White Terrace was at the north-east end of Lake Rotomahana and faced west to north west at the entrance to the Kaiwaka Channel. Te Tarata descended to the lake edge ~25 metres below. The Pink Terrace lay four fifths of the way down the lake on the western shore, facing east to south-east. The pink appearance over the mid and upper basins (near the colour of a rainbow trout) was due to antimony and arsenic sulfides, although the Pink Terrace also contained gold in ore-grade concentrations.
Until recently, the Pink and White Terraces were thought to be about 1,000 years old. In 2016, Prof. Ron Keam stated the hydrothermal system which powered them may be up to 7,000 years old. The silica precipitation formed many pools and steps over time. Precipitation occurred by two methods. The ascending foundation over time formed a lip which would trap the descending flow and become level again. This process formed attractive swimming places, both for the shape and for the warm water. When the thermal layers sloped in the other direction away from the geyser, then silica steps formed on the surface. Both types of formation grew as silica-laden water cascaded over them, and the water also enhanced the spectacle. Geologist Ferdinand von Hochstetter wrote after his visit in 1859 that "doubtless thousands of years were required" for their formation.
The White Terrace was the larger formation, covering ~8 hectares and descending over ~50 layers with a drop in elevation of ~25 metres, and over a distance of ~240 metres. The Pink Terrace descended ~22 metres over a distance of ~100 meters. The Pink Terrace started at the top with a width of 75–100 meters and the bottom layers were ~27 meters wide. Tourists preferred to bathe in the upper Pink Terrace pools due to the temperature, water quality and flexibility of the pool walls.
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Wikipedia