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Thailand’s fossil forests hold international importance for a variety of reasons. The operation of a gravel mine exposed sediment layers containing petrified wood logs, highlighting the critical need to preserve these unique artifacts and address associated environmental concerns. A comprehensive lithological study was conducted on pit walls. Employing 2D ERT and 2D IP methods, geology was classified from the ground surface and validated through drilling logs. The sediment and deposit categorization at gravel pit sites revealed four distinct units: Unit I, conglomeratic sand, exhibiting characteristics typical of fluvial deposits; Unit II, indicating alluvial fan deposition with lenticular gravel and sand highlighting the presence of petrified wood logs; Unit III, massive gravel suggesting channel deposits of an alluvial fan with an abundance of petrified wood; and Unit IV, red soil (collapsible soil). The 2D ERT method successfully examined the boundary sediment layer and mudstone, though classification of sediment units was not achieved. Quaternary terrace sediments underlie the mudstone, identified as an aquitard that effectively prevents surface contamination of the groundwater aquifer. The data from this study serves as fundamental geological information, providing remarkable and essential evidence for the preservation of petrified wood and the safeguarding of the groundwater environment. This site is particularly an outstanding geosite. This research contributes to our understanding of depositional environments and geological processes and proposes conservation strategies. [ABSTRACT FROM AUTHOR]

Abstract Worldwide, silicified woods are found in many geological formations. Significantly, the organic materials of wood are no longer dominant; almost all wood fossils have been mineralized into inorganic silica materials. These unique geological processes must be understood to develop better understanding on organic material fossilization, particularly in the micron scale. Therefore, our aim was to characterize the composition of silicified wood using comprehensive microanalysis. The methods utilized were XRF, ICP-MS, XRD, FTIR, and FE-EPMA. Specimens are from Jasinga, West Java, Indonesia. The results showed that wood silicification was controlled by the infiltration of silica from the host rock into the spaces of the wood structure. In Jasinga, they are controlled by Pliocene tuffaceous sedimentary rocks. The ratio of silica phases revealed a trend in the degree of silicification. Besides silica, the distribution of trace elements also demonstrates the geochemical interaction between the wood fossil and host rock. Wood fossils are affected by the gradual replacement of organic carbon-based materials with silica through silicification. Silica enrichment occurs in the internal of wood, facilitates permineralization and recrystallization. Silica replaces organic material and preserves the wood structures. The microanalytical approach provides comprehensive perspectives on wood petrification, leads to better insights for paleontological studies.

Worldwide, silicified woods are found in many geological formations. Significantly, the organic materials of wood are no longer dominant; almost all wood fossils have been mineralized into inorganic silica materials. These unique geological processes must be understood to develop better understanding on organic material fossilization, particularly in the micron scale. Therefore, our aim was to characterize the composition of silicified wood using comprehensive microanalysis. The methods utilized were XRF, ICP-MS, XRD, FTIR, and FE-EPMA. Specimens are from Jasinga, West Java, Indonesia. The results showed that wood silicification was controlled by the infiltration of silica from the host rock into the spaces of the wood structure. In Jasinga, they are controlled by Pliocene tuffaceous sedimentary rocks. The ratio of silica phases revealed a trend in the degree of silicification. Besides silica, the distribution of trace elements also demonstrates the geochemical interaction between the wood fossil and host rock. Wood fossils are affected by the gradual replacement of organic carbon-based materials with silica through silicification. Silica enrichment occurs in the internal of wood, facilitates permineralization and recrystallization. Silica replaces organic material and preserves the wood structures. The microanalytical approach provides comprehensive perspectives on wood petrification, leads to better insights for paleontological studies. [ABSTRACT FROM AUTHOR]

Fossil wood descriptions are among the most important indicators in understanding forest structures across geological ages. This study was carried out to obtain new findings about the Middle Eocene Climate Optimum (MECO) period of Anatolia with new samples collected from the Middle Eocene-aged fossil area near Amasya-Göynücek. The fossil area falls into the Göynücek Volcanics in the region. Transverse, radial, and tangential microscopic sections were taken from three new fossil wood samples, and all identifications were performed on these microscopic sections. As a result, the fossil species were identified as Pinuxylon cf. P. tarnocziense, cf. Dichrostachyoxylon zirkelii, and Laurinoxylon perseamimatus based on their wood anatomical features. In all three fossil woods, the growth rings are quite wide and their boundaries are indistinct. This indicates the existence of warm tropical conditions in the MECO period. On the other hand, the extant representatives of the angiosperm genera identified here are found in tropical-subtropical forests. Overall, more information was obtained about the forest structure and climate of tropical conditions in the MECO period of Anatolia. [ABSTRACT FROM AUTHOR]

One of the world’s most spectacular fossil forests occurs in Oligocene sediments in an area 30 km east of Cairo known as Gebel El Khashab (Arabic for ‘Wood Mountain’). The locality is popularly known as Maadi Petrified Forest, and New Cairo Petrified Forest. In 1989 the area was established as a protected area. Fossilized wood occurs in the form of trunks that are up to 28 m long and more than one metre in diameter. Non-articulated fossil bones are preserved in the same strata as the petrified wood. For our study, 23 samples of petrified wood, bones, and country rocks collected from G. El Khashab were examined by XRD, XRF, and optical and scanning electron microscopy. All log samples contained silica as the main constituent. With the exception of a single sample that contained opal-CT, quartz was the dominant mineral in the fossil wood. Relict organic matter, as evidenced by weight loss after 500°C heating ranged from 0.14 to 11.62 wt. %, with an average of 4.15 wt. %, with a median value of 1.45%. Silicification preserved anatomical detail, in combination with trace elements that produced colour variations. Iron oxyhydroxides cause the fossil wood to typically have reddish colours. Other accessory minerals include gypsum, fluorite, barite, and calcite. Spherical masses of iron oxide originated as pyrite framboids that became oxidized during diagenesis. Fossil bone consists mainly of carbonate fluorapatite. Diagenetic or weathering activities added several mineral constituents to the fossil bones. Of these, ferruginous minerals are the most abundant. Other secondary minerals include quartz, calcite, dolomite, halite and gypsum. [ABSTRACT FROM AUTHOR]

A collection of petrified wood, hosted by the Natural Sciences Section of the Museum "Vasile Pârvan" from Bârlad, was submitted to a palaeoxylotomical study. The samples come from the central part of Moldova, Northward of Bârlad, and were collected from Simila gravel-quarry, from fluvial-deltaic sediments of Maeotian age, most probably representing reworked elements from a Sarmatian formation which occurs in situ more Northward, in Soleşti-Avereşti-Huşi area. Previous palaeobotanical studies made in that region outlined an interesting Late Miocene Flora on the Moldavian Platform, and the palaeoxylotomical studies confirmed in that area the presence of forests with conifers, elms, oaks and poplars. The results of the present study show the following taxa identified taxa: Glyptostroboxylon cf. rudolphii Dolezych et Van der Burgh, Ulmoxylon scabroides Greguss, Quercoxylon bavaricum Selmeier, Quercoxylon intermedium Petrescu et Velitzelos, Populoxylon tremuloides Iamandei et Iamandei, and Prunoidoxylon multiporosum Dupéron. [ABSTRACT FROM AUTHOR]

Thailand contains two notable fossil forest regions. Pleistocene fluvial sediments in the Tak region in the northern highlands contain silicified trunks of large trees. Deposits in the Khorat Plateau in northeast Thailand contain a multitude of wood fossils that span a probable age range of Miocene to Pleistocene. At Ban Tak fossil logs are primarily mineralized with crystalline quartz. Incomplete mineralization is characteristic of the Tak wood, with intercellular spaces commonly remaining open. The resulting permeability allows penetration of moisture, and allows introduction of microbes and the accumulation of clays, iron oxides, soluble salts and other materials that may cause discoloration and deterioration. Hydration swelling of these components results in stress. Excavation of the huge logs means that they occupy topographically low positions prone to flooding during the monsoon season. These factors make the fossils vulnerable to weathering. A variety of methods have been employed in attempts to reduce the damage, including the construction of various styles of shelters to protect the fossil logs from direct precipitation. At Khorat, compositions of individual specimens range from pure quartz and pure opal to mixtures of the two polymorphs. Many specimens are preserved indoors in the Khorat Fossil Museum in Mueang Nakhon Ratchasima District, both as indoor exhibits and as outdoor displays in a garden plaza. The environmental complexities at the Tak and Khorat fossil wood localities challenge conservators, but their creative attempts provide useful lessons for future preservation efforts. Our report describes the geologic setting and our research mineralogy of specimens at both localities, and discusses conservation strategies. [ABSTRACT FROM AUTHOR]

The early and middle Miocene in Turkey was characterised by a warm climate and a diversified and rich vegetation. Many fossil angiosperm genera have been identified from this period. The present study re-examined previously identified genera and identifed new samples of angiosperm wood remains. The studied material included thin sections housed at the Department of Forest Botany, Division of Forest Engineering, Faculty of Forestry, Istanbul University-Cerrahpasa, and also new ones. Twelve new species are described: Liquidambaroxylon efeae Akkemik sp. nov., Eucarpinoxylon kayacikii Akkemik sp. nov., Ostryoxylon gokceadaense Akkemik sp. nov., Quercoxylon yaltirikii Akkemik sp. nov., Cryptocaryoxylon grandoleaceum Akkemik sp. nov., Fraxinoxylon beypazariense Akkemik sp. nov., Prunoidoxylon prunoides Akkemik sp. nov., Populoxylon sebenense Akkemik sp. nov., Salicoxylon galatianum Akkemik sp. nov. Aceroxylon aceroides Akkemik sp. nov., Ulmoxylon kasapligilii Akkemik sp. nov. and Zelkovoxylon crystalliferum Akkemik sp. nov. In addition, four previously described species are documented for the early and middle Miocene: Pistacioxylon ufukii Akkemik and I. Poole, Fagoxylon radiatum Süss, Laurinoxylon litseoides Süss and Platanoxylon catenatum Süss and Müller-Stoll. In addition to the species descriptions, identification keys are given for all the genera recognised in this study, including all currently known fossil species of the respective fossil genera. These keys hold important new information, as they place the fossil species from Turkey in a wider taxonomic and biogeographic context. The results show that in the early and early-middle Miocene of Turkey a rich woody flora existed in well-drained upland or lowland and riparian areas. This flora comprised subtropical taxa along with warm-temperate taxa indicative of seasonality of rainfall as well as transitions to xeric conditions in the early Miocene.

The Fossil Forest of the Aragoncillo Range is one of several paleontological sites of exceptional scientific value in the Sierra de Selas (Province of Guadalajara, central Spain). This shows an accumulation of silicified tree trunks along with well-preserved macro- and microflora of lower Permian age. This ancient forest, dominated by tree ferns and conifers, was destroyed by volcanic eruptions that took place in many continental areas at this time. This site is in the Molina-Alto Tajo UNESCO Global Geopark, but it is highly vulnerable and has suffered continued impact from plundering. The lack of implementation of legislation that guarantees its conservation does not allow interested visitors to enjoy the site and understand the characteristics of life and climate of such a unique ecosystem from this time in Earth history.

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"Petrified forests" are common tourist attractions, invariably used to promote uniformitarian thinking. One well-known example is in Theodore Roosevelt National Park near Medora, North Dakota, U.S.A. The petrified wood is contained in various strata of the "Paleogene" Fort Union Group in the Williston Basin, but in the park primarily in the lower Sentinel Butte Formation. This formation exhibits much evidence against uniformitarian hypotheses but which fits well with the Genesis Flood. The site shows laterally extensive and vertically limited horizons containing fossilized tree trunks, divorced from fine roots and branches, with no discernible rooting medium such as paleosols, and closely associated with bentonite, iron oxide, and coal. The stratigraphy and sedimentology of the area bespeak continuous, rapid deposition and powerful currents. The uniformitarian scientists also have the problem of how silicification occurs prior to the more rapid normal decay process typical of the supposed swamps which are the interpreted depositional environment for the Fort Union. Burial of vertical trees sinking from log mats and rapid silicification associated with volcanic activity during the Bibilical Flood (responsible for the bentonites) is a more plausible explanation. [ABSTRACT FROM AUTHOR]

Petrified wood samples are found within terrestrial sediments belonging to the Late Oligocene-Early Miocene Danişmen Formation in Malkara-Keşan located in the southwest of the Thrace Basin. The petrified wood in both regions is usually silicified and partly coalified. The silicification of the Tertiary wood in the Malkara-Keşan region is associated with volcanic activity and coeval sedimentation. Thin sections from petrified wood samples were taken as transverse, tangential, and radial sections. The mineralogicalpetrographic- botanical studies were carried out under a polarizing and botanical microscope. Opal-moganite-chalcedony-quartz, which are different polymorphs of silica, were detected under the microscope in the petrified wood. Results were supported by X-Ray Diffractometer (XRD), Confocal Raman Spectroscopy, Fourier Transform Infrared Spectroscopy (FT-IR) analysis, and measurement of density in a total of five samples. In addition, scanning electron microscopy (SEM/EDS) was performed for textures and to determine the average elementary composition of wood samples. Results showed that while crystalline quartz and chalcedony were well defined, opal-A and other polymorphs of silica could be partly examined due to isotropic features. As a result of XRD studies of petrified wood samples from the Keşan and Malkara regions, the peaks of the crystalline types of silica were well defined in the diffractogram patterns. As a result of FT-IR analysis, polymorphs of silica such as quartz-chalcedony-moganite and mineralogical elements similar to carbon and graphite were detected. In two samples, the densities of chalcedony and quartz composition were 2.35 and 2.27 g/cm3, respectively. Furthermore, the average elementary composition was detected with SEM-EDS analysis as O, Si, S, Ca, Cr, and Fe elements in the Keşan region samples and O, Si, S, and Fe elements in the Malkara region samples. The results of all investigations and analyses were interpreted to understand the geodynamic evolution and paleobotanical properties of the region. [ABSTRACT FROM AUTHOR]

Xenoxylon is an important boreal Mesozoic fossil wood genus and has been widely reported from sites across northern China. This paper reports well-preserved Xenoxylon wood from the Jurassic-Cretaceous boundary Tuchengzi Formation at Yanqing, Beijing, China. The fossil wood described here is ascribed to two species, i.e. Xenoxylon latiporosum and X. peidense. The present new finding enrichs our knowledge of the floral characteristics, especially the forest composition of the Tuchengzi Formation. These new records enlarge the fossil wood diversity of the genus Xenoxylon of the Tuchengzi Formation up to three species at Yanqing. Statistic results of the annual and mean sensitivity values of the X. latiporosum and X. peidense indicates that the trees inhabited under a sensitive climate with relatively stable interannual water supply. Additionally, some fungal remains represented by fungal hyphae were found with wood tissues of specimens of X. peidense. Typical wood rotting structures resembling those of the extant white rot are also found in X. latiporosum. This is the first record of fungal hyphae in Yanqing, Beijing, China, and provides us with new evidence that can be used to explore interactions between fungi and plants in the Late Jurassic. Institutional abbreviations: YQ = Yanqing Silicified Wood National Geopark, Beijing, China [ABSTRACT FROM AUTHOR]

Classifications and comparisons of petrified wood are currently based primarily on observable morphologies. The mineralogical characteristics of specimens collected from Qian Jiandian, Yanqing UNESCO Global Geopark, Beijing, China and Sigri, Lesvos Island UNESCO Global Geopark, Greece, were compared in this study to enhance the conservation and protection of Chinese petrified wood. Comparisons were carried out on the basis of internal structural observations using a polarising microscope, x-ray diffraction (XRD), and analysis of major and trace elements. Results show that structures and main chemical components (SiO2) remained almost the same between samples while organic carbon and numerous trace elements (e.g. As, Cu, Mo, Zn) were significantly different. The approaches employed at Lesvos will require modifications in future work, including adjusting adhesives and solvents for different climates, selecting conservation sites and methods based on different preservation conditions, and determining appropriate cleaning methods and agents according to different petrified wood components. The results of this analysis lay the theoretical foundation for petrified wood conservation in Yanqing. Work at this site is the first model study for the preservation of petrified wood in China and creates new opportunities for related research. [ABSTRACT FROM AUTHOR]

Fossil forests are one of the important areas in terms of natural history, paleogeography and paleoclimatology. A new fossil forest was discovered in the area between the Tuzlagedik Tepe and the Sakizocak Tepe, Karatepe, the Alan Tepe, west of the Banaz district of Uşak province. In this area, silicified lateritic formations of Paleogene belonging to 2-60 meters thick are found in silicified tree fossils. The size of silicified tree fossils spread over a wide area reaches up to 1.5 m in length and 70 cm in diameter. The aim of this study is to diagnose these silicified trees, to determine the fossil forest characteristics and to evaluate paleogeography. Transverse, radial and tangent sections were taken from 4 samples which were examined macroscopically. As a result of the analysis it was concluded that silicified trees are Sequoioxylon. The presence of Sequoia trees, which don’t naturally spread in our country today, indicates that there is a marsh forest or riperian vegetation where temperate climatic conditions prevail during the Paleogene.

The early and middle Miocene in Turkey was characterised by a warm climate and a diversified and rich vegetation. Many fossil angiosperm genera have been identified from this period. The present study re-examined previously identified genera and identifed new samples of angiosperm wood remains. The studied material included thin sections housed at the Department of Forest Botany, Division of Forest Engineering, Faculty of Forestry, Istanbul University-Cerrahpasa, and also new ones. Twelve new species are described: Liquidambaroxylon efeae Akkemik sp. nov., Eucarpinoxylon kayacikii Akkemik sp. nov., Ostryoxylon gokceadaense Akkemik sp. nov., Quercoxylon yaltirikii Akkemik sp. nov., Cryptocaryoxylon grandoleaceum Akkemik sp. nov., Fraxinoxylon beypazariense Akkemik sp. nov., Prunoidoxylon prunoides Akkemik sp. nov., Populoxylon sebenense Akkemik sp. nov., Salicoxylon galatianum Akkemik sp. nov. Aceroxylon aceroides Akkemik sp. nov., Ulmoxylon kasapligilii Akkemik sp. nov. and Zelkovoxylon crystalliferum Akkemik sp. nov. In addition, four previously described species are documented for the early and middle Miocene: Pistacioxylon ufukii Akkemik and I. Poole, Fagoxylon radiatum Süss, Laurinoxylon litseoides Süss and Platanoxylon catenatum Süss and Müller-Stoll. In addition to the species descriptions, identification keys are given for all the genera recognised in this study, including all currently known fossil species of the respective fossil genera. These keys hold important new information, as they place the fossil species from Turkey in a wider taxonomic and biogeographic context. The results show that in the early and early-middle Miocene of Turkey a rich woody flora existed in well-drained upland or lowland and riparian areas. This flora comprised subtropical taxa along with warm-temperate taxa indicative of seasonality of rainfall as well as transitions to xeric conditions in the early Miocene. [ABSTRACT FROM AUTHOR]

Thailand contains two notable fossil forest regions. Pleistocene fluvial sediments in the Tak region in the northern highlands contain silicified trunks of large trees. Deposits in the Khorat Plateau in northeast Thailand contain a multitude of wood fossils that span a probable age range of Miocene to Pleistocene. At Ban Tak fossil logs are primarily mineralized with crystalline quartz. Incomplete mineralization is characteristic of the Tak wood, with intercellular spaces commonly remaining open. The resulting permeability allows penetration of moisture, and allows introduction of microbes and the accumulation of clays, iron oxides, soluble salts and other materials that may cause discoloration and deterioration. Hydration swelling of these components results in stress. Excavation of the huge logs means that they occupy topographically low positions prone to flooding during the monsoon season. These factors make the fossils vulnerable to weathering. A variety of methods have been employed in attempts to reduce the damage, including the construction of various styles of shelters to protect the fossil logs from direct precipitation. At Khorat, compositions of individual specimens range from pure quartz and pure opal to mixtures of the two polymorphs. Many specimens are preserved indoors in the Khorat Fossil Museum in Mueang Nakhon Ratchasima District, both as indoor exhibits and as outdoor displays in a garden plaza. The environmental complexities at the Tak and Khorat fossil wood localities challenge conservators, but their creative attempts provide useful lessons for future preservation efforts. Our report describes the geologic setting and our research mineralogy of specimens at both localities, and discusses conservation strategies.

In this study, xeromorphy ratios were calculated for Acer L. (maple) fossil woods in order to infer the precipitation conditions in the Miocene at the sites of the fossils, based on a comparison with the xeromorphy ratios of selected extant Acer species. The four studied petrified wood samples came from three localities of the Galatean Volcanic Province in Turkey: Kozyaka village (Bolu Province, Seben District), İnözü Valley (Ankara Province, Beypazarı District), and Kıraluç precinct between Nuhhoca and Dağşeyhler villages (Ankara Province, Beypazarı District). The calculated xeromorphy ratios ranged from 3 to 18 for the present-day wood and from 13 to 19 for the early Miocene wood. Values over 10 (11–18) represent xeric conditions; the lower values (3–7) indicate mesic conditions in modern Acer woods. The xeromorphy ratios of the Miocene wood indicate xeric conditions; we conclude that the sites of the fossil Acer woods were xeric, very similar to the modern Acer woodlands of central and southern Anatolia.

Fluvial red beds containing anatomically preserved large woody debris shed new light on seasonally dry biomes of the Pennsylvanian–Permian transition and elucidate the concurrence of river depositional systems and vegetation. As a result, the occurrence, distribution and preservation of petrified large woody debris accumulations are considered crucial to understanding the role of arborescent vegetation in shaping fluvial environments. This study reports sizeable silicified trunks and corresponding fluvial architectures from the uppermost Pennsylvanian (upper Gzhelian) Siebigerode Formation (Kyffhäuser, central Germany). The origin, taphonomy and depositional environment of the fossil woods are elucidated by using a multidisciplinary approach including geological mapping, lithofacies analysis, sediment petrography, wood anatomical studies and microstructure analyses. Results reflect the gradual burial of a gentle basement elevation by sand‐bed to gravel‐bed braided rivers at the north‐western margin of the perimontane Saale Basin. Facies architectures resulted from a complex interplay of syndepositional tectonics, repeated palaeorelief rejuvenation, high‐frequency channel avulsion, seasonally dry climate and woody debris–sediment interactions. The alluvial influx and cut‐bank erosion recruited trunks from adjacent semi‐riparian slope habitats vegetated by up to 40 m tall cordaitaleans and conifers. High discharge in wide braids facilitated uncongested transport of large woody debris. Trunk entombment and initial preservation resulted from grounding on barforms, anchoring by attached roots and subsequent burial. The post‐depositional two‐phase silicification was influenced by hydrothermal hematite mineralization and determined a selective wood preservation pattern known as 'pointstone'. Large woody debris‐induced sedimentary structures ('LWDISS') are introduced as a class of sediment structures formed by the biogenic impact on terrestrial deposition. [ABSTRACT FROM AUTHOR]

Background and Aims The Piedra Chamana fossil forest in northern Peru is an assemblage of angiosperm woods and leaves preserved in volcaniclastic rocks dated to 39 Mya (late Middle Eocene). We analysed the anatomical and morphological features of the fossils to reconstruct the palaeoenvironment during this time of global warmth, taking advantage of the co-occurrence of woods and leaves to compare different proxies and analytical approaches. Methods Wood characters analysed include vessel-related functional traits, traits linked to Baileyan trends, and quantitative features such as vessel diameter and density. Diameter-distribution and diameter and position plots are used to represent vessel diameter and arrangement. Leaf margin and area analysis provides additional climate estimates. Key Results The fossil woods show many similarities with modern tropical-forest woods and tropical fossil-wood assemblages; closest correspondence within the Neotropics is to semi-deciduous lowland tropical forest with moderate precipitation (~1000–1200 mm). Features unusual for the modern South American tropics are mainly vessel-related characters (semi-ring porosity, grouped vessels, helical vessel thickenings, short vessel elements) linked to water stress or seasonal water availability. Leaf analysis indicates mean annual temperature of 31 °C (n = 19, 100 % entire-margined) and mean annual precipitation of 1290 mm (n = 22, predominantly microphylls and notophylls). Conclusions The palaeovegetation was clearly lowland tropical forest with a dry aspect, but anomalous aspects of the wood anatomy are consistent with the high temperatures indicated by the leaves and are probably explained by differences in seasonality and water stress compared to the present-day Neotropics. A close modern analogue may be in very seasonal regions of Asia. Pronounced monsoonal (summer-rain) conditions may relate to a location (palaeolatitude of 13°S) outside the near-equatorial tropics. [ABSTRACT FROM AUTHOR]

A palaeoxylotomical study was done on several samples from a private collection of petrified wood found in Bozovici area, which were taxonomically identified. Bozovici area is a small Badenian depression filled by coarse continental deposits, with some interbedded coal and volcanic tuffs. The frequent lateral facies variations and the few fossils of fresh water fauna make difficult a stratigraphic correlation of these deposits. Those samples of fossil wood were identified as remains of Glyptostroboxylon rudolphii Dolezych et Van der Burgh and Spiroplatanoxylon densiradiatum (Petrescu) Süss and an extended discussion concerning the systematics of these taxa was made. Advanced studies on more numerous samples coming from Bozovici area could contribute to a better palaeoenvironmental and palaeoclimatic reconstruction of that area, during Badenian time. [ABSTRACT FROM AUTHOR]

Fossilized wood belongs to the most exciting, however, rarely studied objects in nature. Several kinds of petrified wood with different combinations of minerals have been studied: apatite – calcite; calcite – pyrite; hematite – gypsum wood; quartz - goethite; goethite – calcite woods, from different countries and estimated as old in the time range of 1.8–306 MA. The samples cover nearly the whole time of tree existence on the Earth. The application of synchrotron radiation for X-ray microdiffraction analysis of petrified wood is presented and compared to elemental (electron microprobe) and molecular (micro Raman) analyses with the use of table-top instruments. The analysis of preserved cells permineralized with two minerals allows tracing both the structure of cell walls and the remains of ancient organic matter. Lignin is most often met among the remains of the primary organic matter and is clearly observed in all kinds of wood, except the apatite-calcite one. The Eh-pH diagrams tailored to each combination of minerals with organic matter allow to estimate the original conditions of mineralization and give the indications for the potential biomimetic synthesis. Unlabelled Image • Petrified wood samples from Italy, Poland, and South Africa were investigated. • Synchrotron analysis, electron microprobe and micro Raman techniques were used. • Eh-pH diagrams were determined for fossilized wood. • Mainly lignin, were conserved and formed the network for the cell wall system. • In ancient and contemporary wood, lignin concentration in cell is similar distributed. [ABSTRACT FROM AUTHOR]

Late Tertiary fossil woods from the state of Nevada provide an opportunity for observing the mineralization sequences that cause buried wood to become permineralized. 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. Fossil wood specimens from a single stratum may have different mineralization; silicification may vary even within a single specimen. Despite these variations, several trends are evident. Features in Nevada specimens suggest that two fundamental processes are involved: early mineralization of cell walls, and later silica deposition in lumina, vessels, and rot pockets from groundwater that permeated these open spaces. The process of open-space filling may be analogous to the genesis of geodes and veins, where multiple episodes of hydrothermal precipitation may produce opal, chalcedony, and quartz as deposits within a single cavity. Silica polymorphs may coexist as primary precipitates, or they may originate from solid-state transformation of a single parent material. Relic lepisphere textures observed in some chalcedony wood specimens are evidence of opal→chalcedony transition. In Nevada, specimens that contain crystalline quartz, this mineral appears to have been formed by direct precipitation in open spaces, not from recrystallization of chalcedony. Opal-A has seldom been reported in fossil wood, but this amorphous material is fairly common in Nevada specimens.

The fragments of petrified wood from the Permian deposits at the territory of Tatarstan were studied. Petrified wood is characterized by silification of the plant tissue with retention of its primary texture. Wood samples were investigated using optical microscopy, carbon isotope analysis, and electron microscopy with microprobe analysis. The mechanisms of substitution of the wood organic matter with soluble and colloidal silica were specified. Details were provided on paleoclimatic conditions for the growth of higher plants during the period of Permian sedimentation.

In this study, xeromorphy ratios were calculated for Acer L. (maple) fossil woods in order to infer the precipitation conditions in the Miocene at the sites of the fossils, based on a comparison with the xeromorphy ratios of selected extant Acer species. The four studied petrified wood samples came from three localities of the Galatean Volcanic Province in Turkey: Kozyaka village (Bolu Province, Seben District), İnözüValley (Ankara Province, BeypazarıDistrict), and Kıraluçprecinct between Nuhhoca and Dağşeyhler villages (Ankara Province, BeypazarıDistrict). The calculated xeromorphy ratios ranged from 3 to 18 for the present-day wood and from 13 to 19 for the early Miocene wood. Values over 10 (11-18) represent xeric conditions, the lower values (3-7) indicate mesic conditions in modern Acer woods. The xeromorphy ratios of the Miocene wood indicate xeric conditions; we conclude that the sites of the fossil Acer woods were xeric, very similar to the modern Acer woodlands of central and southern Anatolia. [ABSTRACT FROM AUTHOR]

The Ban Tak Petrified Wood Forest Park is the most extensive Petrified Wood Park of Thailand, where is discovered the most significant ancient tree fossil of Asia. The aim of this study for determining the age and interpretation in paleoenvironment of both sediments and the petrified wood. The stratigraphic column suggests they have six sediment layers and these fossils were found in gravel layer. The layer of gravel graded to fine sediments depends on the water flow in the river at humid paleo-environment. The Thermoluminescence age dating data suggest that these ancient trees grew for a long time (120,000-130,000 years ago) before subversion and deposited during 20,000-53,000 years ago. These fossils are rare geologic materials and have high value for appropriate conservation. Geotourism is the best tool for promoting this geoheritage and other geosites near this park include Lan Sang Waterfall, Ping River, Pha Sam Ngao, and Bhumibol Dam. This study is educating people to realize and obey and to follow the rule of park headquarters for geoconservation by understanding the geologic process of the petrified wood and geosite in Tak. Also, both the economy and society in this town can develop by effectively geotourism management. [ABSTRACT FROM AUTHOR]

Subsurface fluid systems are important for chemical weathering, ore formation and thermal evolution of the crust. Changes in the dynamics and distribution of subsurface fluid flow systems are controlled by changes in global and regional terrestrial climate, tectonics, and elevation. This paper concerns the dating of changes in ancient subsurface hydrologic systems. However, direct dating of water-rock interaction is challenging because of the lack of appropriate materials to date and the more open and complex nature of subsurface flow regimes. Here, we explore the prospects of using U-Pb dating of petrified (silicified) wood as a means of quantifying continental paleo-hydrology. Oxidizing fluids, often of meteoric origin, tend to leach and mobilize U from the country rock, but when such waters contact organic-rich material, U can become reduced and immobilized, resulting in U-rich silicified wood. We present in situ laser ablation ICPMS analyses of U-Pb isotopes and trace elements in petrified wood from the Upper Triassic Chinle Formation (225–208 Myr) in the Petrified Forest National Park in Arizona (USA), allowing us to establish a generalized workflow for making meaningful paleo-hydrologic interpretations of the U-Pb systematics of silicified wood. Wood characterized by brownish colors and preservation of cellular structure have low Fe contents and positive Ce anomalies, indicating silicification in reducing environments and isolation in relatively reduced conditions after silicification, resulting in closed system behavior of U and Pb. Wood characterized by vivid colors (orange, red, etc.) and little to no preservation of cellular structure are much higher in Fe and exhibit negative Ce anomalies, indicating influence by more oxidized fluids. The brownish samples yield U-Pb ages clustered between 250 and 200 Ma with a peak coinciding with the time of deposition (~220 Ma), which indicates that fossilization largely took place almost immediately after deposition and that U-Pb in quartz faithfully retains the time of such fossilization. In contrast, the orangish-reddish-whitish samples yield younger U-Pb ages, defining distinct errorchron ages, which reflect subsequent generations of quartz crystallization. Scatter associated with errorchrons are likely due to local (mm- to cm-scale) U or Pb mobility or variable initial Pb composition. Distinct younger age peaks appear to correlate with the timing of regional unconformities associated with tectonic or epeirogenic uplift. We suggest that uplift and exhumation may initiate the onset of oxidizing fluid systems, resulting in leaching and transport of U from the surroundings, followed by subsequent generations of quartz precipitation. In summary, U-Pb dating of petrified wood or silicified organic material, has high potential for dating paleo-hydrologic events. However, due to complexities in terrestrial hydrologic systems, interpretations of U-Pb systematics must be informed by accompanying geochemical and textural observations. [ABSTRACT FROM AUTHOR]

Gorontalo area is part of the arc volcano - plutonic North Sulawesi predominantly volcanic rocks and intrusif rock Eocene to Quaternary. The tectonic position makes the Gorontalo area of natural resource mining prospects both metallic and non metallic minerals. One of them is a non-metal potential of petrified wood. The purpose of this study to analyze the condition of geomorphology, lithology, stratgraphy, and determine the nature of the physical characteristics of petrified wood in order to formulate feasibility as gemstones. The method used qualitative and quantitative results of the field survey which is then compiled the results of the laboratory. Field analysis in the form of geological mapping, sampling and documentation of geological data. The laboratory analysis conducted mineralogical and geochemistry analysis in the form of X-Ray Diffraction (XRD) and X-Ray Fluorescence (XRF). Dissemination of research results, the petrified wood in Tohupo River and Molannihu River. Petrified wood found in fluvial and alluvial sediment in tuffaceous sandstone layer with two types of insitu and transported. Results of laboratory analysis both mineralogy and gochemistry indicates that the mineral constituent of petrified wood are Quartz (SiO2) with good quality so worty as a gemstone because of its aesthetic, translucent and hardness 7 Mohs Scale.

Petrified wood has traditionally been divided into two categories based on preservation processes: permineralization (where tissues are entombed within a mineral-filled 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 processes; instead, both processes may occur contemporaneously during diagenesis. Infiltration of mineral-bearing groundwater may initially cause permineralization of cellular tissues, but the wood is undergoing gradual degradation. The degree of anatomical preservation thus depends on the relative rates of mineral precipitation and tissue destruction. Rapid rates of mineralization under relatively mild Eh and pH conditions favor the preservation of organic matter. These conditions appear to be more common for calcium carbonate deposition than for silicification, based on observations of fossil woods from many localities. Because of these preservational complexities, "mineralization" and "mineralized" are more accurate as general descriptive terms than "permineralization" and "permineralized". [ABSTRACT FROM AUTHOR]

The Bruneau Woodpile site has long been popular among fossil collectors; however, the deposit has received scant attention from scientists. Our research reveals that the fossilized wood was deposited ca. 6.85 Ma, within the Chalk Hills Formation, and was mineralized with carbonate-fluorapatite. The diverse assemblage of conifers and hardwoods is representative of the warm temperate forests that flourished in southwest Idaho, USA during the late Miocene. Limb and trunk fragments preserved in a single thin sandstone bed appear to represent woody debris that was transported by streams. One possible explanation is that wood, pumice, and sandy volcaniclastic sediment arrived separately as a result of ordinary stream action, and later were combined into a single assemblage during a subsequent high-energy sedimentation event. We favor an alternate hypothesis: a catastrophic event (e.g., a windstorm) damaged trees on slopes bordering the ancient lake. Branches and small trunk fragments were carried by wind and rain into local streams and ponds where they became waterlogged. After a delay that allowed pumice and wood to become saturated, storm water transported these materials, along with finer volcaniclastic sediment, into a lake. The resulting density current produced a fining-upward sedimentary cycle where wood was preserved in the lowest, coarsest stratum. [ABSTRACT FROM AUTHOR]

An extensive fossil forest discovered in 2010 on private property in central Colorado, USA, has not previously been described in scientific literature. Horizontal partial logs originated as fluvially transported driftwood. A preliminary study of petrified wood specimens reveals evidence of a complex mineralization sequence that involved multiple episodes of mineral deposition, combined with diagenetic transformation of silica minerals. Specimens from two logs have opalized cell walls. However, minerals filling the cell interiors of these specimens vary. Vessel lumina are filled with chalcedony or crystalline quartz; tracheid lumina may contain opal or chalcedony. Specimens from 5 other logs contain quartz/chalcedony, but relict textures suggest cell walls were originally mineralized with opal that was later converted to microcrystalline silica. Pyrite, calcite, and iron oxides were observed as minor constituents in some specimens, providing additional evidence that fossilization occurred in multiple stages, with temporal and spatial variations in physical and chemical conditions causing episodic precipitation of various minerals within the buried wood. Trace element analyses suggest that Fe is the main source of fossil wood color. [ABSTRACT FROM AUTHOR]

Different geophysical tools such as resistivity, seismic refraction, and magnetic survey have been applied to delineate the subsurface stratigraphy and structural elements, which controlled the distribution and origin of the Petrified wood in Qattamiya, Cairo, Egypt. Land magnetic survey was carried out in the study area through two stages, the first stage includes all area by measuring 11,674 stations and the second stage was carried out in the detailed area that was located at the southeastern part of the all area including 9441 stations. All measurements have been corrected for diurnal variation and reduced to the north magnetic pole. The results of magnetic interpretation indicated that the area dissected by different structural elements trend toward NE–SW, NW–SE, N–S and E–W directions. Twenty-eight samples have been collected from the detailed area to analyze for magnetic susceptibility values. Four electrical resistivity tomography (ERT) profiles were measured by using dipole–dipole configuration to estimate the vertical and lateral variation of the subsurface sequence. Results of quantitative interpretation of the ERT data indicate that the subsurface sequence consists of different geoelectric units; the first unit is characterized by high resistivity values upto 1000 ohm m corresponding to sand, gravel and Petrified wood at the surface and extends to a depth of a few meters. The second geoelectric unit is corresponding to sandy clay which exhibits moderate resistivity (few hundred ohm m) values with thickness ranging from 6 to10 m. The third geoelectric unit is characterized by very low resistivity corresponding to clay of depth ranging from 10 to 30 m overlaying the fourth unit which reached to a depth ranging from 30 to 56 m and characterized by very high resistivity (8000 ohm m) corresponding to limestone. Three shallow seismic refraction spreads of geophone spacing 7.5 m were measured to investigate the subsurface sequence, where the results of interpretation indicate that the subsurface section consists of three units of average velocity 500, 2000 and 4000 m/s, respectively corresponding to sand, gravel and Petrified wood, sandy clay, clay and limestone. [ABSTRACT FROM AUTHOR]

• Chapter 1. PaleoParks: Our paleontological heritage protected and conserved in the field worldwide, by Jere H. Lipps, p. 1-10, 20 figs. • Chapter 2. The Triassic Guanling fossil Group - A key GeoPark from Barren Mountain, Guizhou Province, China, by Xiaofeng Wang, Xiaohong Chen, Chuanshang Wang & Long Cheng, p. 11-28, 30 figs., 2 tables. • Chapter 3. The GeoPark of Haute-Provence, France - Geology and palaeontology protected for sustainable development, by Jean-Simon Pagès, p. 29-34, 11 figs. • Chapter 4. The protection and use of the geological and paleontological heritage in Baja California Sur, Mexico, by Javier Gaitán Morán & Alejandro Álvarez Arellano • Capítulo 4. El resguardo y aprovechamiento del patrimonio geológico y paleontológico en Baja California Sur, México, por Javier Gaitán Morán & Alejandro Álvarez Arellano, p. 35-48, 4 figs. • Chapter 5. Protecting fossil sites in New Zealand, by Bruce W. Hayward, p. 49-64, 10 figs., 6 tables. • Chapter 6. The Salt Range: Pakistan's unique field museum of geology and paleontology, by Shahid Jamil Sameeni, p. 65-73, 28 figs. • Chapter 7. Paleontological parks and museums and prominent fossil sites in Thailand and their importance in the conservation of fossils, by Nareerat Boonchai, Paul J. Grote & Pratueng Jintasakul, p. 75-95, 13 figs. • Chapter 8. Managing fossil resources at the Falls of the Ohio, Indiana and Kentucky, USA: A fossil park in an urban setting, by Alan Goldstein, p. 97-101, 8 figs., 1 table. • Chapter 9. Paleo-piracy endangers Vendian (Ediacaran) fossils in the White Sea - Arkhangelsk region of Russia, by Mikhail A. Fedonkin, Andrey Yu. Ivantsov, Maxim V. Leonov, Jere H. Lipps, Ekaterina A. Serezhnikova, Eugeniy I. Malyutin & Yuriy V. Khan, p. 103-111, 12 figs. • Chapter 10. Copper Canyon track locality (Pliocene) conservation strategies, Death Valley National Park, USA, by Torrey Nyborg, p. 113-119, 4 figs. • Chapter 11. A possible Late Miocene fossil forest PaleoPark in Hungary, by Géza Császár, Miklós Kázmér, Boglárka Erdei & Imre Magyar, p. 121-133, 19 figs.

This paper introduces two new Miocene fossil forest sites in northwest Turkey. Both sites lie at an altitude of ~ 900 m close to the town of Seben in the province of Bolu. One locality is near the village of Hoçaş; the second lies 17 km to the northwest of the village of Kozyaka. The silicified wood represents lower parts of trunks that were felled by an eruption associated with volcanic activity in the Galatean Volcanic Province. The Hoçaş site yielded a total of 64 samples (51 in situ and 13 ex situ ). Eight in situ trunks have been identified as Salix L. /Populus L., Palmae , Juniperus L . , Liquidambar L. and Quercus L. (evergreen); ex situ Cedrus Trew., Picea Mill. and Acer L. were found lying on the surface of the soil. The Kozyaka site yielded a total of 26 samples (six in situ , 20 ex situ ) including Cedrus , Pinus L., Acer , Salix/Populus , evergreen Quercus and Ulmus L. Today in Turkey these genera grow in coastal locations across a narrow altitudinal range. Collating data found herein with evidence from previous studies suggests that during the early Miocene subtropical to warm temperate conditions prevailed that supported a lakeside vegetation at the Hoçaş site and a more typical upland or mountainous zone assemblage around the Kozyaka site. [ABSTRACT FROM AUTHOR]

The Early Cretaceous Jehol Biota, one of the most important Mesozoic lagerstätten in East Asia, is especially well-known for occurrences of fossil feathered dinosaurs and early angiosperms. However, the terrestrial biodiversity, especially the fossil wood record, is poorly known. In this study, several structurally preserved coniferous wood specimens from the Lower Cretaceous Yixian Formation are investigated, based on collections from the Heichengzi Basin in Beipiao of western Liaoning, Northeast China. Four species referred to four genera of fossil wood are described, including Taxodioxylon heichengziense sp. nov., Thujoxylon beipiaoense sp. nov., Sciadopityoxylon liaoningense Ding and Protocedroxylon shengjinbeigouense sp. nov. These new records enlarge the fossil wood diversity of the Yixian Formation up to 10 species in 9 genera, and provide further insights into the forest vegetation composition of the Early Cretaceous Jehol Biota. Systematic analysis of the floral constitution indicates that the petrified forests of the Yixian Formation are dominated by conifers, represented by Araucariaceae, Podocarpaceae, Sciadopityaceae, Pinaceae and Cupressaceae in the western Liaoning region. Palaeoclimatical analysis of the fossil wood assemblage implies that the western Liaoning region was dominated by a cool temperate, wet and seasonal climate with variable interannual water supply in the western Liaoning region during the Early Cretaceous. [ABSTRACT FROM AUTHOR]

Fossil forests have world-wide 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 analysis of trace metals in 35 silicified wood samples, determined using LA-ICP-MS spectrometry. The most important of these metals is Fe, which can produce a rainbow of hues depending on its abundance and oxidation state. Cr is the dominant colorant for bright green fossil wood from Arizona, USA and Zimbabwe, Africa. Complex color patterns result from the progressive nature of the fossilization process, which causes wood to have varying degrees of permeability during successive episodes of permineralization. These processes include simple diffusion, chromatographic separation, infiltration of groundwater along fractures and void spaces, and oxidation/reduction. [ABSTRACT FROM AUTHOR]