夏瑪爾的七色土：彩虹不只天上有

The impressive "Seven Colored Earths of Chamarel" is named for the strange natural colors of a fairly small area （roughly 7500 square meters） covered in sand dunes2） made of clay minerals that formed from basaltic3） lava in South Western Mauritius， an island in the Indian Ocean. The seven different colors are red， yellow， green， blue， violet4）， purple and brown， and they are capable of forming truly remarkable patterns. This is due to the fact that the different colors， being comprised of different clay minerals， naturally settle into layers， or bands， each of a different color， with different colors being more or less distinct as light hits them from different angles at different times of the day.

在印度洋中坐落著一個名為毛里求斯的島國，其西南部有一塊很小的地區(qū)（約7500平方米），這里布滿了由玄武質巖漿形成的粘土礦物所構成的一座座沙丘。這些沙丘自身的顏色非常奇特，景色非凡，“夏瑪爾的七色土”便由此得名。這七種不同的顏色分別為紅色、黃色、綠色、藍色、紫羅蘭色、紫色和棕色，它們可以組成無比壯觀的圖案。這是因為這些不同的顏色（由不同的粘土礦物所組成）天然地分層或呈帶狀分布，彼此顏色各異，而且在一天之中的不同時段，當陽光從不同的角度照到不同的顏色上時，就會有某種顏色或多或少地突顯出來。

A Strange Geographic Anomaly5）

奇特地貌

Although Geological Science has explained the different colors of the sand as being the result of molten lava cooling at different rates due to inconsistent temperatures and forming oxides6） of various metals including iron and aluminium7）， they have not fully explained its tendency to settle into layers. And no place on earth of a similar geography is known. While places like Australia and Papua New Guinea have similar terrain8）， the same seven colors are not present. Some organizations have thought about excavating at the site to determine the cause of this phenomenon， but have elected not to risk9） destroying the formation. If you wish to have some of the sand for your own， however， some local gift shops in Chamarel sell small vials10） of it.

Luckily， the dunes do not seem to be facing complications due to erosion， despite the heavy rains that often drench11） the island， which is another mystery. The rains do， however， leave their mark as they travel over the dunes， leaving patterns of criss-crossing12） channels13） as they go， resulting in web-like patterns changing with each storm and making the dunes even more beautiful.

地質學已對這些沙為什么會呈現(xiàn)出不同的顏色做出了解釋（由于溫度不恒定，導致熔巖以不同的速度冷卻，形成了含有鐵、鋁等各種各樣金屬的氧化物，從而產生了不同的顏色），可是卻沒有解釋清楚為什么這些顏色總會分層，而且也并沒聽說地球上有其他地方具有相似的地貌。盡管澳大利亞、巴布亞新幾內亞等地也有類似的地貌，但卻沒有出現(xiàn)與此相同的七色景觀。一些機構曾考慮過進行就地挖掘，以查明該現(xiàn)象的成因，但還是決定不去冒險破壞這一景觀。不過，如果你想自己收藏一點彩沙的話，夏瑪爾當?shù)氐囊恍┒Y品店出售小瓶的七色彩沙。

幸運的是，盡管島上時常會大雨傾盆，但這些沙丘似乎并沒有遇到雨水侵蝕引發(fā)的各種問題，這又是一個謎團。然而，雨水流經(jīng)沙丘時的確會留下痕跡，它們流經(jīng)之處都會留下縱橫交錯的溝壑組成的各種圖案，而且這些錯綜復雜的圖案還會隨每場暴雨變化，使沙丘變得愈發(fā)美麗。

Some time between the dunes&apos； discovery and there having been turned into a privately owned tourist attraction sometime in the 1960&apos；s， visitors were not allowed on the dunes due to their tendency to take the odd and beautiful sand home with them， though a small network of trails leads around them with large elevated observation decks at intervals. While the trails allow visitors to get a close look at the dunes， and associate themselves with some of the region&apos；s wildlife， including tortoises， the observation decks allow more impressive views of larger expanses of the park.

The dunes， which are entirely devoid14） of vegetation， mysteriously arise out of a patch of dense forest. Whether some strange anomaly prevents the growth of vegetation or whether owners remove any by hand in order to preserve the park&apos；s beauty is up to speculation. But their rising out of the forest has been guessed at. Some have suggested that the area was once cleared for the production of sugarcane， for which the island was most used in the 17th century， but rain washed away the topsoil， revealing the dunes and leaving them unfit to sustain a crop. Most of the island&apos；s natural wildlife and vegetation was eradicated during this period of British colonization， making the island&apos；s involvement in tourism in 2014 an important step towards preserving what is left of the island&apos；s natural history15）. This time may have permanently changed the geography of the island， but it has also made the area more interesting.

從沙丘被發(fā)現(xiàn)到這里在20世紀60年代某個時候變?yōu)橐惶幩綘I旅游景點之間的一段時間，游客是不可以踏上沙丘的，因為他們總愛帶點這種奇特又好看的沙子回家。不過沙丘四周縱橫交錯的步道可以指引游客四處轉悠，步道上每隔一段距離還建有高高架起的大觀景臺。步道讓游客能近距離地觀賞沙丘，還能親近該地區(qū)的一些野生動物，比如烏龜；而觀景臺則讓游客可以欣賞到沙丘公園視野更為廣闊、更壯觀的景色。

這些沙丘完全寸草不生，卻不可思議地出現(xiàn)在一片茂密的森林之中。是某種奇特的反常現(xiàn)象阻礙了植被的生長？還是所有者為保全這個公園的美景而人工清除了長出來的任何植被？這就只能去推測了。不過，人們一直在猜測森林里為什么會冒出這么一片沙丘。有人認為，這個地區(qū)曾被開墾出來種植甘蔗（這是毛里求斯島在17世紀最主要的用途），但雨水沖走了表土，露出了沙丘，從而使其不適宜作物生長。島上大部分的野生動植物在英國殖民統(tǒng)治的這一時期都被消滅殆盡，這使得毛里求斯2014年對旅游業(yè)進行的投入成為保存該島現(xiàn)有動植物的重要舉措。這一時期或許永久地改變了該島的地貌，不過它也使這一地區(qū)變得更有吸引力。