Silicified wood occurs abundantly in Middle Miocene flows and sedimentary interbeds of the Columbia River Basalt Group (CRBG) in central Washington State, USA. These fossil localities are welldated based on radiometric ages determined for the host lava. Paleoenvironments include wood transported by lahars (Ginkgo Petrified Forest State Park), fluvial and palludal environments (Saddle Mountain ...
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An extensive lithic workshop and raw material procurement site was discovered near West Rainy Butte, Slope County, North Dakota, in 1982 during the University of North Dakota archaeological field school. The site covers over 500,000 m2 on a small ridgetop approximately 2 km southwest of West Rainy Butte (Fig. 1). Pebble, cobble, and small bouldersized pieces of silicified material (chert) are ...
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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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Coal balls occur in the paralic coal basins (those of coastal swamps) of Carboniferous age in America and Europe. Strangely, the coalforming coastal swamps of Tertiary and ~retaceous age have never yielded coal balls of a similar type, although some equivalent but somewhat different types of permineralization occur (Gothan, 1937, ...
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Oligocene and Miocene caldera basins contain abundant petrified wood that ranges in composition from incipient silicification to complete permineralization. Examination of specimens from 21 localities reveals that the petrifaction sequence can follow multiple pathways.
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In Oregon, permineralized and petrified wood is generally preserved by silica derived from the alteration of volcanic rocks. In Ohio through Iowa another form of permineralized plant is found within coal seams, preserved by calcite in nodules colloquially called "coal balls". In black shales, plant material is permineralized by pyrite, again ...
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The sediment mineral and traceelement contents of silicified wood and associated sediments from the Petrified Forest National Park, Arizona, indicate that silica mineralization occurs within the compositional range of most stream and groundwaters. ... In modern examples, the biofilm is robust enough to persist after separation, or rotting of ...
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and sideritization, whereby silicified, calcified and dolomitized coal balls are best preserved (Zheng et al. 2008). Significantly, the number of fossil wood specimens in western Liaoning is very high, and most of them are silicified. Anatomically, the majority of fossil wood specimens from western Liaoning contain wellpreserved secondary
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The mechanism of wood coalification initiates with a biochemical process where wood is transformed into peat (peatification) and then trough aerobic and anaerobic reactions (humification and gelification) into soft brown coal (lignite) [35], [36], [37].Subsequently, via a geochemical process through elevated temperature and pressure, soft brown coal is converted into hard brown coal ...
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silicified specimens, leaving the original wood intact" [5]. The problem with these conjectures is the scarcity of supporting evidence. Petrifaction of plant tissues via cellular permineralization is well documented for calcareous coal balls, siliceous lagerstätten, and silicaencrusted wood in modern hot springs, as well as
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The good preservation of the new fossil wood yields significant palaeoenvironmental information. The lack of marked growth rings in both specimens and the presence of tyloses in Dadoxylon suggest that the climate in the intramontane basins of the Pyrenees was slightly seasonal towards the end of the Carboniferous.
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Petrified wood has traditionally been divided into two categories based on preservation processes: permineralization (where tissues are entombed within a mineralfilled matrix) and replacement (where organic anatomical features have been replicated by inorganic materials). New analytical evidence suggests that for most petrified wood, permineralization and replacement are not independent ...
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A study of silicified wood from the Triassicaged Chinle Formation of Arizona supports the parameters above. Sigleo (1979) compared the geochemistry of silicified wood and its associated sediments (sandstone with some siltstone and clay) to determine the environmental conditions for the process of wood mineralization.
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The most comprehensive studies on silicified wood were made by Felix (1897), Kraut (1933), Storz (1933), Strómer (1933) and Hellmers (1949), the latter, however, not giving much new information.
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This guide was written to serve as a tool for the identification, occurrence, production and use of Florida's most common rocks and minerals. It was primarily intended to be a simplified general reference for the student; therefore, technical information and detailed descriptive material were minimized. Some of the terminology used in these ...
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Permineralised plant material is very scarce in the CantabrianAsturian fold belt, being restricted to a mention of coalballs from the upper Westphalian of Lieres in Asturias (Renier, 1926) and welldocumented coalball specimens at Truébano in the province of León, presumably of late Namurian age (Beckary, 1987a, Beckary, 1987b, Beckary and ...
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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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Coal balls may provide clues for understanding petrifaction of woods where calcite is the principal mineral constituent. ... Two of the bestknown examples are the Devonian Rhynie Chert in Scotland, and Silicathe Eocene precipitated Princeton inChert peat in bogsBritishmay Columbia, entomb Canada. plant At remains, both localities, providing ...
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Petrified wood has traditionally been divided into two categories based on preservation processes: permineralization (where tissues are entombed within a mineralfilled matrix) and replacement...
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The No. 2 coal seam of the Witbank coalfield, for example, documents a switch from icehouse to greenhouse conditions in the Early Permian. ... Gee describes over sixty silicified seed cones with preserved internal anatomy from eleven localities in northeastern and southern Utah. The silicified cones were compared in size, gross morphology and ...
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silicified beds. Kbentonites are also prevalent in the Permian basins of West Texas (Nicklen, 2003) where silicified faunas are common. Silicification has the ability to provide a highfidelity snapshot of life on Earth when it is pervasive. For example, beds in the Silurian of Gotland, with complete infiltration of matrix and
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Silicified Dadoxylontype wood occurs in different horizons of sandy/arkosic fluvial facies and is more common; one of the best known is the Štikov Arkoses of the Kumburk Formation, which is stratigraphically correlated with the Žaltman Arkoses in the ISB due to the occurrence of those fossils (Pešek et al., 2001). Fossiliferous Stará Paka ...
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It has already been proposed that silicified wood denotes a certain palaeoclimatic meaning (, Skoček, 1974, Lefranc, 1975, Beauchamp, 1981, Fielding and Alexander, 2001, Wagner and Mayoral, 2007, Colombi and Parrish, 2008, Matysová et al., 2009, Mencl et al., 2009), which should be further elaborated. ... Studies of coal balls of the ...
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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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Stein [23] made the generalization th at quartz in silicified wood was typically a result of diagenetic tran sformati on from an opaline precursor. This opal A → opal CT →
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The exceptional preservation of plant fossils falls into two categories: whole plant preservation and anatomical detail. Whole plant preservation is controlled primarily by transport and event preservation (, ash falls), whereas anatomical preservation can occur through one of several taphonomic pathways: compressionimpression, silicification, coalball formation, pyritization, and ...
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Fossil forests have worldwide distribution, commonly preserving mineralized wood that displays vivid hues and complex color patterns. However, the origin of petrified color has received little scientific attention. Color of silicified wood may be influenced by the presence of relict organic matter, but the most significant contribution comes from trace metals. This study reports quantitative ...
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and sideritization, whereby silicified, calcified and dolomitized coal balls are best preserved (Zheng et al. 2008). Significantly, the number of fossil wood specimens in western Liaoning is very high, and most of them are silicified. Anatomically, the majority of fossil wood specimens from western Liaoning contain wellpreserved secondary
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