Measuring density of silicified wood and determining weight loss after 450 °C heating provides useful data for interpreting the process of permineralization. ... (1974) hypothesised that silicified stems, frequently found 2000), and from the wellknown coal balls from the Pennsylvanian of in transitional formations from Pennsylvanian rocks of ...
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Ancient forests that once stood tall and dark are now buried, making their way back into daylight as coal. Researcher Patrick G. Hatcher wants to know how. "One problem with studying how wood converts to coal is that the reactions take place over an extremely long period," said Hatcher, who is an associate professor of fuel science and geosciences at Penn State. When trying to duplicate those ...
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The first phase in the stepwise collapse of the Carboniferous Coal Forests occurred near the DesmoinesianMissourian boundary (early Kasimovian, ~ 307 Ma), and involved extirpation of Lycosporaproducing lepidodendrids, and some other lycopsids, across most of tropical this paper, we followup on historical reports of silicified treestumps in Peoria County, northwestcentral ...
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The three specimens analysed, up to 25 cm in diameter, were found to belong to the same type of wood; they are described on the basis of the best preserved specimen. The permineralised axes are wellpreserved with a parenchymatous pith, endarch primary xylem and pycnoxylic secondary xylem.
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Usually occurs with bone or wood. Each pore in the material is filled with a mineral (usually agate or jasper). • Carbonization. The plant or animal is flattened between layers of finegrained sediment, and most organic molecules are forced out leaving behind only carbon (frequently occurs in fish fossils in shale). • Molds and casts.
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The examples are silicified wood, coalballs etc. The coalballs are of localised occurrence which are irregularly rounded concrete masses, commonly made up of calcite containing preserved fragments of coal forming plants. Each coalballs contains calcium carbonate, magnesium carbonate and sometimes iron sulphate. 2.
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The bestknown and moststudied petrified wood specimens are those that are mineralized with polymorphs of silica: opalA, opalC, chalcedony, and quartz. Less familiar are fossil woods preserved ...
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Silicified wood provides evidence of microbial degradation. ... We describe and quantify characteristics and magnitudes of postmortem shrinkage in fossil wood based on examples of silicified stems from various late Paleozoic to Cenozoic geological settings and localities. 2. ... as mainly seen in coal balls or cherts (, Schopf, 1970, ...
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Abstract In the vicinity of Yücepinar Village of Zile district of Tokat province, there are silicified wood formations in agglomerate levels in the Çekerek formation Middle Eocene aged. These formations consist of well— preserved tree trunks of about m in diameter or branches and trunk parts in mm—1 m length. Generally, they are openbrownish cream; in some places they demonstrate ...
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Coal types: Hard coals. Bituminous coal is harder and blacker than lignite and subbituminous coal, and can be divided into two types: thermal and metallurgical. Together, they make up 52 percent ...
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Permineralization is well documented for plant tissues preserved in calcareous "coal balls", modern hot spring sinter, and some fossiliferous cherts, and in these specimens significant amounts of relict organic matter may be preserved.
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The bestknown and moststudied petrified wood specimens are those that are mineralized with polymorphs of silica: opalA, opalC, chalcedony, and quartz. Less familiar are fossil woods preserved with nonsilica minerals. This report reviews discoveries of woods mineralized with calcium carbonate, calcium phosphate, various iron and copper minerals, manganese oxide, fluorite, barite, natrolite ...
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Examples of various types of preservation of fossil lycopsid wood. ... permineralized with calcium carbonate in coal balls, and as ... The density of silicified wood can be used to evaluate the ...
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The 1930 discovery of Carboniferous lycopsid fossils in south central Colorado resulted in the naming of a new species of scale tree, Lepidodendron johnsonii (=Lepidophloios johnsonii (Arnold) DiMichele). Cellular structures of L. johnsonii axes and periderm are preserved in silica—an unusual mode of fossil preservation for Pennsylvanian lycopsid plant remains. The early reports on the Trout ...
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The roof sedimentary rock layer with carbonaceous claystone lithology must be carried out with an Xray diffraction (XRD) clay oriented analysis to identify the clay mineral composition which influences the formation of silicified coal. 2. Geological Setting. Regionally the research area is included in the Barito Basin.
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The bestknown and moststudied petrified wood specimens are those that are mineralized with polymorphs of silica: opalA, opalC, chalcedony, and quartz. Less familiar are fossil woods preserved ...
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Among amateur fossil wood enthusiasts, silicified wood has long been divided into two categories: opalized and agatized. However, the mineral compositions of these spec
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When a fossil organism is subjected to mineral replacement, it is said to be petrified. For example, petrified wood may be replaced with chalcedony, or shells replaced with pyrite. This means that out of all fossils, only the creature itself could be fossilized by petrification . And not all fossil organisms are petrified.
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The bestknown and moststudied petrified wood specimens are those that are mineralized with polymorphs of silica: opalA, opalC, chalcedony, and quartz. Less familiar are fossil woods...
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Calcareous Mineralizaton, Including Coal Balls First described in 1855 [11], coal balls are calcareous concretions that widely occur in Carboniferous coal beds. A summary of the extensive literature can be found in [12]. Preservation of plant remains is variable, but many specimens show excellent anatomical detail.
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The above procedure is similar to that used in studying coal ball introduced by Taylor et al. (2009), excluding the first three steps,, sectioning and polishing the material, etching each section of fossil wood in dilute hydrochloric acid (5%, 10 min). This is because our material is a polished silicified wood with clear transverse, radial ...
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Cellulose acetate sheet. FIGURE Diagrammatic representations of the steps involved in the preparation of the coal ball peel technique. A. Section of coal ball slab (calcium carbonate matrix) containing plant material (crosshatched); B. coal ball slab after acid etching to partially expose plant material; C. etched coal ball slab surface with cellulose acetate sheet in place; D. cellulose ...
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A silicified gymnospermous wood, Yangquanoxylon miscellum gen. nov. et sp. nov., is described from the Upper Pennsylvanianlower Permian Taiyuan Formation, Yangquan City, Shanxi Province, North China. The pycnoxylic wood is composed of thickwalled tracheids and thinwalled rays. It is characterized by mixed radial tracheid pits, uniseriate and homogeneous rays, occurrence of scalariform ...
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Wood has silicified quickly in the natural Pieces of fresh wood 58 cm in diameter and 10 cm long were placed in the Tateyama Hot Spring. The spring water, with a pH of 3, an average water temperature of 70ºC, and a high silica content, precipitates amorphous opal spheres that range in size up to 10 µm in diameter.
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The bestknown and moststudied petrified wood specimens are those that are mineralized with polymorphs of silica: opalA, opalC, chalcedony, and quartz. Less familiar are fossil woods preserved ...
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North Dakota petrified wood is variously preserved, from specimens that are well silicified, to splintery, and even grading to lignite coal (coalified trees). The degree of petrification can even vary within a single specimen; individual stumps or logs sometimes contain both well silicified and coalified parts.
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"coal balls" and other calcareous concretions, ... Two of the bestknown examples are the D evonian Rhynie Chert in ... Color of silicified wood may be influenced by the presence of relict ...
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Examples described in this report range from dolomite wood that contains quar tzfilled fractures (Washington, USA) to silicified wood that contains abundant copper minerals (Turkey "colla wood").
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For many decades, wood silicification has been viewed as a relatively simple process of permineralization that occurs when silica dissolved in groundwater precipitates to fill vacant spaces within the porous tissue. The presence of specific silica minerals is commonly ascribed to diagenetic changes.
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petrified wood, fossil formed by the invasion of minerals into cavities between and within cells of natural wood, usually by silica (silicon dioxide, SiO 2) or calcite (calcium carbonate, CaCO 3 ). The petrified forests of the western United States are silicified wood, the tree tissues having been replaced by chalcedony (cryptocrystalline ...
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A material supplier from Belgium would like to produce limestone powder for his custome...
India is rich in various mineral resources and it is an important mineral processing market
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