矽化木(Petrified Wood)
主要成分:二氧化矽
年代:中生代三疊紀晚期
發現地:Holbrook, Arizona, USA(美國)
說明:
矽化木,是樹木遺骸經過長期的化學元素替換過程而形成的化石。本館藏木化石來自於亞利桑納州北部的「化石森林國家公園」(Petrified Forest National Park),是世界上最大的矽化木森林。出產自該地的木化石相較於其他標本而言,擁有著美麗而獨特的絢爛七彩,因此在眾多木化石標本中佔有獨一無二的地位。本館館長李承倫先生曾多次赴當地交流考察,使本館能擁有美麗繽紛的木化石收藏。
Petrified wood is a fossil formed from the remains of trees which underwent long periods of mineralization. The fossils seen in our collection originated from the Petrified Forest National Park in Arizona, which is the largest petrified forest in the world. Tree fossils from the park feature vibrant iridescent coloring compared to other specimens, cementing its place in the hierarchy of petrified wood. The curator of our museum, Mr. Richard Lee, travelled there many times, giving us a gorgeous collection of the fossils.
化石森林國家公園在三疊紀末期時(約2億2500萬年前)是布滿巨大針葉樹的沼澤地。因為地處沼澤,樹木倒塌後會迅速遭泥淖掩埋,達成了形成化石的適當條件。在化石形成過程中,周圍泥土的二氧化矽、硫化鐵、碳酸鈣等礦物質緩慢滲入樹幹中心,同時樹幹外層的有機木質被漸漸分解,在經過千萬年的交代作用(Metasomatism)後,美麗的七彩木化石便呈現在您眼前。
The Petrified Forest National Park was a morass covered with giant conifers some 225 million years ago. Due to the swamp, trees were quickly buried after falling–ideal conditions for fossilization. During the process, the organic remains of the tree were replaced by minerals such as silicon dioxide, iron sulfide and calcium carbonate. After millions of years of metasomatism, the fossils were created.
侏羅紀小學堂;
「你知道嗎?透過化石中絢爛的色彩我們能進一步判斷木化石中的礦物成分喔。灰色是代表矽;藍色與綠色代表鈷、鉻、銅等;而紅色、棕色以及黃色則是代表氧化鐵!」
DID YOU KNOW
Did you know that we can determine the mineral content of a wood fossil from its color?
(資料來源維基與化石狂人誌)