Dissertation / PhD Thesis/Book

PreJuSER-55795

http://join2-wiki.gsi.de/foswiki/pub/Main/Artwork/join2_logo100x88.png Biomacromolecules of Fossil Algae, Spores and Zooclasts from Selected Time Windows of Proterozoic to Mesozoic Age as Revealed by Pyrolysis-Gas Chromatography-Mass Spectrometry : A Biogeochemical Study

Dutta, S. (Corresponding author)FZJ*

2006
Forschungszentrum Jülich GmbH Zentralbibliothek, Verlag Jülich
ISBN: 3-89336-455-2, 978-3-89336-455-8

Please use a persistent id in citations: http://hdl.handle.net/2128/2489

Abstract: This study has revealed the molecular composition of extraordinarily well preserved palynomorphs (organic-walled microfossils) from selected time windows of Proterozoic to Mesozoic time. Sedimentary rock samples were collected from 11 localities: Hazro area (SE Turkey), Ruhr Basin (Germany), Weilerbach-Quierchied (Germany), Zwickau (Germany), Alstätte Embayment (German-Dutch border), Wülfrath (Germany), Gotland (Sweden), Oklahoma (USA), Virginia (USA), Rampura (India) and Tasmania (Australia). All samples are of low thermal maturity (Rock Eval T$_{max}$ 418°C (R$_{c}$~0.40) - 444°C (R$_{c}$~0.75)), except sediments from Suket Shale (Rampura, India). Palynomorphs which are taxonomically well assigned by project collaborators have been handpicked from the total organic residues. For the present investigations, various types of palynomorphs, for example, $\textit{Tasmanites, Leiosphaeridia}$, chitinozoans, scolecodonts, various megaspores and $\textit{Chuaria circularis}$ have been selected. An approach combining microscopy, Micro-Fourier transform infrared (FTIR) spectroscopy and pyrolysis-gas chromatography-mass spectrometry (Py-GC-MS) has been applied. $\textit{Tasmanites}$ (thick-walled) and $\textit{Leiosphaeridia}$ (thin-walled) are assigned to prasinophycean green algae. Although, $\textit{Tasmanites}$ and $\textit{Leiosphaeridia}$ are morphologically distinct, their overall chemical compositions are similar. The pyrolysates from both thick-walled and thin-walled prasinophytes are dominated by a series of $\textit{n}$-C$_{6-22}$ alkene/alkane doublets which are typical of pyrolysis products of algaenan, the microbiological resistant algal biopolymer. The pyrolysates of the $\textit{Tasmanites}$ from Tasmania (Upper Carboniferous/Lower Permian) show a normal tricyclic terpenoid product distribution, but no traces of tricyclic terpenoids have been detected from the pyrolysates of $\textit{Tasmanites}$ from Turkey (Dadas Formation, Upper Silurian/Lower Devonian) and USA (Arbuckle Mountains, Oklahoma, Upper Devonian/Lower Carboniferous and Chattanooga Shale, Upper Devonian, Virginia). However, the pyrolysates of $\textit{Leiosphaeridia}$ from Turkey show the presence of monounsaturated and diunsaturated tricyclic terpenes as well as monoaromatic tricyclic terpanes. Hence, the inherent source-biomarker relationship between the $\textit{Tasmanites}$ and tricyclic terpenoids does not always exist. Furthermore, tricyclic terpenoid pyrolysates of the $\textit{Leiosphaeridia}$ confirms that there are more than one biological source(s) of these biomarkers and they are not exclusively from or always diagnostic of $\textit{Tasmanites}$. $\textbf{Chitinozoans}$ represent a group of flask-like, marine, organic-walled microfossils with uncertain biological affinity. Biomacromolecules of Chitinozoa (Dadas Formation, Upper Silurian, SE Turkey) of present investigation consist of both aliphatic and aromatic moieties. Aromatic pyrolysis products predominate over aliphatic pyrolysis products. Alkylbenzenes, alkylnaphthalenes, alkylphenols and alkylphenanthrenes are the major aromatic compounds found in the pyrolysates of Chitinozoa. A series of $\textit{n}$-alkene/$\textit{n}$-alkane doublets in the pyrolysates represents the aliphatic moiety. Micro-FTIR data are consistent with the pyrolytic studies emphasizing that biomacromolecules of the Chitinozoa investigated in the present study consist of both aromatic and aliphatic components. No pyrolysis products diagnostic of chitin have been detected in the present study. It is unlikely that the original macromolecules of Chitinozoa before fossilization were made of chitin related compounds. Chitinozoans belong to a group of rare marine fossils that have a substantial amount of ‘lignin-like’ macromolecular matter. Both spectroscopic and pyrolytic investigations demonstrate that the sporopollenin of the fossil $\textbf{megaspores}$ (from Cretaceous and Pennsylvanian sediments, Germany) consists of both aliphatic [...]

Note: Record converted from VDB: 12.11.2012
Note: RWTH Aachen, Diss., 2006

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Research Program(s):

1. Geosysteme - Erde im Wandel (P21)

Appears in the scientific report 2006

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Database coverage:

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