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The Pink Terraces, or Otukapuarangi ("fountain of the clouded sky") in Māori, and the White Terraces, also known as Te Tarata ("the tattooed rock"), were natural wonders of New Zealand.〔(【引用サイトリンク】publisher=Rotorua Museum )〕 They were lost, and for long after were thought to have been completely destroyed, by the 1886 eruption of Mount Tarawera, being replaced by the Waimangu Volcanic Rift Valley. The Terraces were formed by geothermally heated water containing large amounts of silicic acid and sodium chloride from two large geysers. These geysers were part of a group of 40 geysers in the nearby area. The Pink and the White Terraces were 800 metres apart. The White Terraces were at the north end of Lake Rotomahana and faced away from the lake at the entrance to the Kaiwaka stream. They descended to the lake edge 40 metres below. The extra sunlight they received from facing north gave them a more bleached or white appearance. The Pink Terraces were about two thirds of the way down the lake sheltered from the harsh sun on the western shores, facing south-east. Their pink appearance (near the colour of a rainbow trout) was largely due to less sunlight reaching them and therefore less bleaching. ==Formation== The foundations for both terraces were formed from alternate layers of volcanic fallout over a long period of time. The volcanic debris layers, alternating between rhyolitic and sedimentary stone, formed the base for precipitation of silica. The 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 Terraces were the larger formation, covering 3 hectares and descending over approximately 50 layers and a drop in height of 40 metres. The Pink Terraces descended 30 metres over a distance of 75 metres. The converging Pink Terraces started at the top with a width of 75–100 metres and the bottom layers were approximately 27 metres wide. The Pink Terraces were where people preferred to bathe due to the more suitable pools. 抄文引用元・出典: フリー百科事典『 ウィキペディア（Wikipedia）』 ■ウィキペディアで「Pink and White Terraces」の詳細全文を読む スポンサード リンク
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