- Petrified wood
Petrified wood (from the Greek root "petro" meaning "rock" or "stone", literally "wood turned into stone") is a type of
fossil : it consists offossil wood where all the organic materials have been replaced withmineral s (most often asilicate , such asquartz ), while retaining the original structure of the wood. Thepetrifaction process occurs underground, when wood becomes buried undersediment and is initially preserved due to a lack ofoxygen . Mineral-rich water flowing through the sediment deposits minerals in the plant's cells and as the plant'slignin andcellulose decay away, a stone mould forms in its place. It probably takes less than 100 years for wood to petrify. [http://www.nps.gov/pefo/faqs.htm]Elements such as
manganese ,iron andcopper in the water/mud during the petrification process give petrified wood a variety of color ranges. Pure quartzcrystal s are colorless, but when contaminants are added to the process the crystals take on a yellow, red or other tint.Following is a list of contaminating elements and related color hues:
*carbon - black
*cobalt - green/blue
*chromium - green/blue
*copper - green/blue
*iron oxide s - red, brown, and yellow
*manganese - pink/orange
*manganese oxide s - black/yellowPetrified wood can preserve the original structure of the wood in all its detail, down to the microscopic level. Structures such as
tree ring s and the various tissues are often observed features.Petrified wood has a
Mohs hardness of 7, the same as quartz.Petrified wood is the provincial stone of
Alberta and also thestate gem ofWashington .Locations
*
Argentina - Considered to be one of the world's best petrified reserves, the Petrified Forest National Monument in Chubut Province in the ArgentinePatagonia has many trees that measure more than 3 m (10 ft) in diameter and 30 m (100 ft) long. Compared to petrified trees in theUnited States that measure less than 1.8 m (6 ft) in diameter, the trees of the Central Steppes of Argentina are significantly larger.
*Belgium - Geosite Goudberg nearHoegaarden . [cite web |url=http://home.hccnet.nl/Jacob.Leloux/hoegaarden.html |title=A petrified forrest near Hoegaarden]
*Canada - In thebadlands of southernAlberta ; petrified wood is the provincial stone of Alberta.Axel Heiberg Island inNunavut has among the largest petrified forests in the world
*Czech Republic ,Nová Paka - The most famous locality onPermian -Carboniferous rocks in the Czech Republic.
*Germany - The museum of natural history inChemnitz has a collection of petrified trees found in the town in 1737.
*Egypt petrified forest in Cairo-Suez road, declared a national protectorate by the minstery of environment, also in the area of New Cairo at the Extension of Nasr city, El Qattamiyya, near El Maadi distrect, Al Farafra oasis [http://bio.kuleuven.be/sys/iawa/PDF/IAWA%20J%2021-25/24%20(2)%202003/24(2)%20163-172.pdf] , Al Fayoum depression and actually the entire western desert [ [http://www.touregypt.net/featurestories/fossils.htm Fossils: The Other Ancient Egypt ] ] .
*Greece -Petrified Forest of Lesvos , at the western tip of the island of Lesbos, is possibly the largest of the petrified forests, covering an area of over 150 km² and declared a National Monument in 1985. Large, upright trunks complete with root systems can be found, as well as trunks up to 22 m in length.
*Libya -Great Sand Sea - Hundreds of square miles of petrified trunks, branches and other debris mixed with Stone Age artifacts.
*United States - Some of the better known petrified wood sites include:
**Petrified Wood Park inLemmon, South Dakota .
**Ginkgo/Wanapum State Park in Washington State
**Grotto of the Redemption , a private park inIowa .
**Petrified Forest National Park inArizona
**Petrified Forest (California) inCalifornia
*Australia - Has vast deposits of petrified and opalised wood.
*India - A geological site famous for its petrified woodsThiruvakkarai Village inChennai ,Tamil Nadu . The site is protected by theGeological Survey of India . Petrified woods covers a large area in this site.
*New Zealand -Curio Bay onthe Catlins coast contains many petrified wood examples.Artificial petrified wood
Artificial petrified wood has been produced in a Washington lab. In the process small cubes of pine were soaked in an acid bath for two days then in a silica solution for another two. The product was then
cook ed at 1400 °C in anargon atmosphere for two hours. The result wassilicon carbide ceramic which preserved the intricate cell structure of the wood. Soaking in atungsten solution produced atungsten carbide petrified wood. [ "Petrified Wood in Days", Physorg.com, January 25, 2005 http://www.physorg.com/news2801.html ] ["Presto! Instant Petrified Wood Created in Lab", Live Science, 27 January 2005 http://www.livescience.com/technology/050127_petrified_wood.html ]ee also
*
Petrified palmwood
*"Araucarioxylon arizonicum "
*Petrified Forest of Lesvos References
External links
* [http://www.aegean.gr/Petrified_Forest/NoFrames/petriforest.htm The Petrified forest of Lesvos - Protected Natural Monument]
* [http://www.novapaka.muzeum.cz/index_en.htm The Town Museum of Nová Paka]
* [http://www.mspetrifiedforest.com The Mississippi Petrified Forest]
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