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Cerne uhli
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Cerne uhli je jednim z nejvyznamnejsich fosilnich paliv, hornina biologického puvodu. Jde o tzv. pevny kaustobiolit (recky: kaustos=horlavy, bios=zivot), tedy nerostne palivo v tuhem skupenstvi, ktere vzniklo z nahromadenych odumrelych rostlinnych latek a zbytku nizsich zivocichu usazujicich se v bazinach.
Uhli vznikalo geochemickou fazi zvanou prouhelnovani z organickeho materialu za nepristupu vzduchu. Postupnou premenou vrstev odumrelych stromu pusobenim tlaku za
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nepritomnosti vzduchu se prechazelo z faze trouchniveni, raselineni az k prouhelnovani, coz melo za nasledek snizovani obsahu kysliku a vodiku a narust uhliku. Tyto procesy mají za nasledek soucasne i rozpad struktury rostlin a jejich postupne tmavnuti, coz propujcuje cernému uhli jeho typickou barvu.
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Tyto procesy probihaly zhruba pred 320 miliony let, tedy v prvohorach - v obdobi zvanem 1). Behem teto doby vznikly vsechny zasoby cerného uhli na celem svete. Toto obdobi je charakterizovano predevsim mohutnymi horotvornymi procesy, mohutnou sopecnou cinnosti i vznikem bazinatych lagun, v nichz rostly obri preslicky, plavune a kapradiny.
Na uzemi dnesní hornoslezske uhelne panve se prave takoveto bazinate laguny rozkladaly. Obdobi rozvoje rostlinstva stridaly privaly bahna. Ve vetsich hloubkach se pak z rostlinnych tel stavalo uhli, zatimco bahno se menilo na piskovce, slepence a jilovce. Za 40 milionu let se tak v hornoslezské panvi postupne vytvorilo pres 400 uhelnych sloji, prokladanych jinymi horninami. Z techto slojí je vsak tezitelnych jen neco pres 80. Cele souvrstvi tehdy dosahlo mocnosti pres 3 kilometry.
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Koncem prvohor mohutne tektonicke pochody puvodne vodorovne vrstvy zvrasnily v pohori, ktere pak behem druhohor a tretihor zcasti odnesla eroze. Na konci tretihor pred priblizne 20 miliony let pri takzvanem karpatskem vrasneni se na jejich zbytky nasunuly od jihu dalsi vrstvy. Puvodní karbonske horniny tak v okoli Ostravy tvori kopce, kde kdysi vychazely uhelne sloje az k povrchu.
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Práve takovyto dnes uz jedinecny vychoz lze nalezt na uvedenych souradnicich.
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Vychoz je tvoren stridajicimi se vrstvami piskovcu, sedych prachovcu, jílovcu, tzv. "korenové pudy" s nakupenim fosillizovanych korenu rostlin, a sloje cerneho uhli. Vasim dalsim ukolem bude najit zminenou sloj a odhadnout jeji mocnost (sirku) a sklon ve stupnich. Pokud jste fandove do zkamenelin, lze se rozhlednout v hromade suti pod vychozem a najit si nejaky ten kousek zkamenele prvohorni flory - muzete ho i vyfotit a prilozit k logu.
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Slození uhli:
Uhli je slozeno predevsim z uhliku (74 – 91%), vodiku a kysliku, obsahuje vsak take dalsi chemicke prvky predevsim siru a obcas take radioaktivni primesi (uran). Dle slozeni se deli na nekolik typu, sem patri:
- Lignit - s podilem 30-50% uhliku, jedna se nejmene kvalitni uhli
- Hnede uhli s podilem 50-80% uhliku
- Cerne uhli s podilem 80-90% uhliku
- … 2) s podilem uhliku 90% a více
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Podminky pro zalogovani:
Pro zalogovani teto EC odpovezte prosim na nize uvedene otazky a odpovedi zaslete na mail pres můj profil. Pokud bude něco v neporadku – ozvu se.
Zjistete nazev prvohorniho obdobi, ve kterem cerné uhli vzniklo
Zjistete nazev ctvrteho, nejkvalitnejsiho typu cerneho uhli – k cemu se pouziva
Na miste odhadnete mocnost uhelne sloje a jeji sklon
Jaka byla celkova mocnost celeho uhelneho souvrství hornoslezke panve ?
Co se nachazi u cesty pred vychozem?
Prilozte foto sebe nebo sve GPS u uhelneho vychozu – dobrovolny ukol
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Black Coal
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Black coal is one of the most important fossil fuels, rock of biological origin. This is called a solid caustobiolith (Greek: caustos = flammable, bios = life), so mineral fuel in the solid state, which arose from accumulated dead plant matter and lower animals residues settling in prehistoric swamps. Coal were created during geochemical phases called coalification from the organic material protected from air. Gradual transformation layers of dead trees by the pressure in the absence of air passed from the stage of rot, to coalification, which resulted in a reduction of oxygen and hydrogen and carbon growth. These processes simultaneously causing the disintegration of the structure of plants and their gradual darkening, this gives its typical coal black color.
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These processes took place about 320 million years ago, in the Paleozoic - during the period known as 1). All coal reserves in the Word were formed during this time. This period is characterized mainly by massive folding processes, massive volcanic activity and creation of marshy lagoons in which grew a giant horsetails, club mosses and ferns.
On the territory of present-day Upper Silesian coal basin is just such marshy lagoon decompose. Period of development of vegetation alternated torrents of mud. At greater depths, then from the plant body became coal, while mud turned into sandstone, conglomerates and mudstones. After 40 million years, and in the Upper Silesian Basin gradually developed over 400 coal seams, interspersed with other rocks. Of these seams is recoverable only slightly over the 80. The entire thickness of layers was reached over 3 kilometers.
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At the end of the Paleozoic a massive tectonic processes caused that the originally horizontal layers were transformed into the mountains, which then during the Mesozoic and Tertiary partly eroded. At the end of the Tertiary, before about 20 million years ago, during the so-called Carpathian folding the residues from the south pushed onto this layer. Therefore the hills around Ostrava consist of the original Carboniferous rocks, where coal seams passed through to the surface in the past.
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Just such a surface outcrop of black coal can be found at the coordinates.
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The outcrop consists of alternating layers of sandstone, gray siltstone, claystone, called "root land" with the accumulation of fossil plant roots, and coal seams. Your next task will be to find the aforementioned coal seam and estimate its thickness and inclination in degrees. If you are a fan in fossils, you can look around - in a pile of rubble below the outcrop - and find a small piece of Paleozoic fossilized flora - you can even take a photo and attach it to the log.
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The composition of coal:
Coal is composed primarily of carbon (74-91%), hydrogen and oxygen, but also contains other chemical elements primarily sulfur and sometimes radioactive impurities (uranium, etc.). According composition is divided into several types, these include:
- Lignite - with a share of 30-50% carbon, this is the lowest quality coal
- Brown Coal with a share of 50-80% carbon
- Black Coal with a share of 80-90% carbon
- ... 2) with carbon 90% or more
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Logging conditions:
To log this EC please answer the following questions and answers, send mail via your profile. If something is wrong - I'll call.
Find out the Paleozoic period in which the coal was formed?
Find out the name of the fourth, the highest quality type of coal - what it is used for?
On-site try to estimate thickness of the coal seam and its inclination.
What was the total thickness of the entire coal formations of Upper Silesian Basin?
What is in the road front of the outcrop?
As a voluntary task attach photo yourself or your GPS at the coal outcrop.
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