Study of fossil wood by modern analytical methods: case studies

Silicified woods belonging to the three-dimensional permineralised plants are thoroughly studied by palaeobotanists. Their importance is usually underestimated in other scientific disciplines, their mineralogy/geochemistry is poorly known in close relation to other known scientific data. Stone-like...

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Bibliographic Details
Main Author: Matysová, Petra
Other Authors: Sakala, Jakub, Soták, Ján, Dietrich, Dagmar
Format: Thesis
Language:English
Published: Univerzita Karlova, Přírodovědecká fakulta 2016
Subjects:
Online Access:https://hdl.handle.net/20.500.11956/82401
Description
Summary:Silicified woods belonging to the three-dimensional permineralised plants are thoroughly studied by palaeobotanists. Their importance is usually underestimated in other scientific disciplines, their mineralogy/geochemistry is poorly known in close relation to other known scientific data. Stone-like appearance and nature of silicified wood is valued mainly in mineralogical markets. Only a complex analytical view can reveal more about their taphonomic past, palaeoenvironments and mechanisms of their formation and preservation. This PhD thesis aims to uncover the potential of instrumental analyses of permineralised woods and design remarkable procedures of observing the wood samples. I have performed petrographical and geochemical analyses and comparison of samples of the Pennsylvanian (Carboniferous) to the Late Triassic age from several localities in the Czech Republic, Germany, Brazil, Sultanate of Oman, Mongolia, USA - Arizona, France, and Antarctica. The selected samples, in most cases taxonomically determined, were observed in qualitative and quantitative way by instrumental imaging and analytical tools. Bulk (XRD) and detailed point analyses were performed. As the samples are very old, the crystallinity of SiO2 was high (α-quartz was their main constituent according to XRD). A rather rare. Zkřemenělá dřeva, která se řadí mezi permineralizované rostliny v trojrozměrné podobě, jsou odjakživa předmětem studia paleobotaniků. V jiných vědních disciplínách je jejich význam obvykle podceňován, jejich mineralogie a geochemie je málo známá a tudíž není vztahována ani k dalším známým faktům z jiných oborů. Kamenný vzhled a vlastnosti zkřemenělého dřeva jsou ceněny hlavně na mineralogických burzách. Pokud chceme více pochopit tafonomii těchto dřev a mechanismus jejich vzniku a zachování a poznat paleoprostředí, ze kterého tyto fosílie pocházejí, je nutný celostní přístup. Tato disertační práce si klade za cíl odhalit možnosti instrumentálních analýz permineralizovaných dřev a navrhnout nevšední postupy zkoumání ...