Pink and White Terraces

The Pink Terrace, or Te Otukapuarangi in Māori, and the White Terrace, also known as Te Tarata, 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 . The main tourist attractions included Ngahapu, Ruakiwi, Te Tekapo, Waikanapanapa, Whatapoho, Ngawana, Koingo and Whakaehu.The Pink and the White Terrace springs were around 1200m 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 around 25m 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 was due to antimony and arsenic sulfides, although the Pink Terrace also contained gold in ore-grade concentrations.FormationUntil recently, the Pink and White Terraces were thought to be about 1,000 years old. 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.