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EarthCache

Strazce z praveku / Guard from the prehistory

A cache by CIRA Send Message to Owner Message this owner
Hidden : 1/21/2008
Difficulty:
1 out of 5
Terrain:
1 out of 5

Size: Size: not chosen (not chosen)

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Geocache Description:


Tato earthcache Vás zavede do plzenských mestských sadu ke geologicky zajímavým zkamenelin stromu.

This earthcache misleads you to geologicaly interesting remains of fossilized trees, which are situated in area of pilsener parks.


Strážce z praveku / Guard from the prehistory

zkamenelý geostrom


Zkamenelý strom je druh fosílíe, která vznikla procesem zvaným karbonizace. Tato earthcache Vás privede pred budovu Západoceského muzea do Šafaríkových sadu, kde mužete najít nekolik ukázek fosilních kmenu stromu, které sem byly dovezeny ze dvou obcí ležících nedaleko Plzne.

Karbonizace je pyrolytický rozklad organických látek bez prístupu vzduchu a za vzniku tuhých, kapalných a plynných produktu. Podle konecné teploty rozkladu vzduchu je karbonizace napríklad uhlí nízkotepelná (do 600 °C) a vysokotepelná (do 1 200 °C). Produkty karbonizace jsou napríklad dehet a karbonizacní plyn.

A jak vlastne fosílie obecne vznikají?
Nejcasteji tak, že živocich nebo rostlina uvízne v usazeninách, obvykle pod vodou. I když se masité cásti tela takto pohrbených živocichu rychle rozloží, tvrdé složky, kosti a skorápky zustanou zachovány, v nekterých prípadech prakticky bez poškození. Vetšinou však prosakující voda cástecne nebo úplne zanese páry a dutiny nerostnými usazeninami a promení je v kámen. V prípade dreva muže být puvodní hmota postupne, molekulu za molekulou, nahrazována minerály, predevším oxidem kremicitým. V tomto prípade se zachovají puvodní charakteristické rysy vcetne letokruhu , ba dokonce i bunecné struktury.

Fosilizace muže probehnout i tak, že puvodní struktury zcela zmizí a zanechají po sobe bud dutinu, nebo jakousi prírodní "formu" ve skále. Obcas do techto forem pronikají jiné materiály, které pak vytvárejí odlitek originálu. Formám "na listy" a jiné tenké struktury se ríká otisky. Puvodní obrysy listu a živocichu s mekkým telem se mužou uchovat také v jemném nánosu bahna. Zvlášt krásné jsou takto vzniklé jemné prokreslené otisky kapradin



Pro uznání vašeho logu je zapotrebí splnit 2 následující úkoly:

  • vyfotit se spolu se strážcem z praveku
    (POZOR! NA FOTCE MUSÍ BÝT VIDET CELÁ VAŠE POSTAVA (samozrejme bez zakryté tváre)! VŠECHNY LOGY S NEVYHOVUJÍCÍMI FOTOGRAFIEMI BUDOU BEZ VAROVÁNÍ SMAZÁNY )
    Podívejte se na example foto.


  • poslat mi na email názvy dvou obcí, odkud byly tyto zkamenelé kmeny stromu do Plzne dovezeny
    (informace se dá lehce zjistit, stací se procházet po sadech a rozhlížet se kolem sebe)


fossil



Fossilized tree is kind of fossils, which is formed by process called carbonization. This earthcache leads you to place, where you can find several remains of these type of fossils. These remainds of fossilized trees are situated in front of the building of West-Bohemia museum in Safarik’s park. They were brought to this place from two villages near Pilsen.

Carbonization or Carbonisation is the term for the conversion of an organic substance into carbon or a carbon-containing residue through pyrolysis or destructive distillation. It is often used in organic chemistry with reference to the generation of coal gas and coal tar from raw coal. Fossil fuels in general are the products of the carbonization of vegetable matter.
When biomaterial is exposed to sudden searing heat (as in the case of an atomic bomb explosion or pyroclastic flow from a volcano, for instance), it can be carbonized extremely quickly, turning it into solid carbon. In the destruction of Herculaneum by a volcano, many organic objects such as furniture were carbonized by the intense heat.
In one study a new catalyst was developed for the generation of biodiesel from ethanol and fatty acids such as oleic acid or stearic acid by carbonization of simple sugars such as glucose and sucrose. The sugars were processed for 15 hours at 400 °C under a nitrogen flow to a black carbon residue consisting of a complex mixture of polycyclic aromatic carbon sheets. This material was then treated with sulfuric acid which functionalized the sheets with sulfonite, carboxyl and hydroxyl catalytic sites.




If you want to log this cache, you have to complete two following tasks:

  • take a photo of you with the fossilezed tree
    ATTENTION! THE WHOLE YOUR BODY MUST BE SEEN ON THE PHOTO (of course without cover face)! ALL THE LOGS WITH INCORRECT PHOTOS WILL BE DELETE WITHOUT WARNING. Look to the example foto.


  • send me via email names of two villages, where these fossilezed trees were brought to Pilsen from
    (this information you can find out in these pilsener parks)


Special thanks to Georgecz for creating the listing of this earthcache.


Additional Hints (No hints available.)



 

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Last Updated: on 6/16/2018 3:13:27 PM Pacific Daylight Time (10:13 PM GMT)
Rendered From:Unknown
Coordinates are in the WGS84 datum

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