Geochemical Significance of Biomarkers in Paleozoic Coals vorgelegt von Dipl.-Chem. Antje Armstroff aus Ludwigshafen Der Fakult¨at VI - Bauingenieurwesen und Angewandte Geowissenschaften der Technischen Universit¨atBerlin zur Erlangung des akademischen Grades Doktorin der Naturwissenschaften - Dr. rer. nat. - genehmigte Dissertation Promotionsausschuss: Vorsitzender: Prof. Dr. W. Dominik Berichter: Prof. Dr. B. Horsfield Berichter: Prof. Dr. R. Littke Tag der m¨undlichen Pr¨ufung:14. Juli 2004 Berlin 2004 D 83 Acknowledgement This thesis was performed at the Institute for Sedimentary Systems (ICG-V) at the Research Center J¨ulich. First of all I would like to thank my supervisors Prof. Brian Horsfield and Dr. Heinz Wilkes at the Research Center J¨ulich and now at the GFZ Potsdam for their support. I always found them ready to discuss scientific issues and ideas. I would also like to thank Prof. Ralf Littke from the Institute of Geology and Geochemistry of Petroleum and Coal at the Aachen University of Technology for the valuable input he provided to this thesis. Many thanks for the pleasant co-operation are extended to all persons involved in the project of this thesis. I wish to thank Dr. Jan Schwarzbauer from the University of Technology in Aachen for constructive discussions which were very productive for the progress of my dissertation. I also would like to thank Dipl.- Geol. Birgit Gieren (Univ. Aachen) who worked on a co-project and performed the microscopy of the samples. Dr. Chris Wheatley from the Geological British Survey helped to organise the samples from British locations and contributed substantially on finding literature for the specific locations. Prof. Hans Kerp, University of M¨unstercontributed the samples from Russia. I would also like to thank Dr. Wolfgang Peters-Kottig, University of M¨unster who, within many discussions helped me to assign the age of the Russian samples. Dr. Bojesen- Koefoed of GEUS (Denmark) is acknowledged for providing the samples from the Ravnefjeld Formation. Prof. Schneider and Dipl.-Geol. Frank K¨orner(both University of Freiberg) contributed the samples from France. I especially wish to thank Frank K¨orner for giving me insights in his investigations on the geology of this specific samples. Additionally thanks are extended to Dipl.-Geol. Hartkopf- Fr¨oderat the GLA in Krefeld who contributed the two fossils. Thanks are extended to all my colleagues at the ICG-V in J¨ulich. Technicians, scientists and Ph.D. students at the ICG-V provided an excellent working envi- ronment. Thanks especially to Dr. Thomas Fischer, Dr. Andreas Fuhrmann, Dr. Thomas Oldenburg, Dr. Jochen Naeth and Dr. Klaus Zink, Stephan Gerisch, Ul- rich Herten, Marina Kloppisch and Oliver Kranendonk. This thesis would not have been possible without the support and expertise of Franz Leistner, Helmut Willsch, III Ulrich Disko, Anne Richter, Wolfgang L¨udke, Willi Benders, Christoph Mathesius, Werner Laumer and many others from the Organic Geochemistry group. Addi- tionally thanks are extended to M. Kleikamp from the library at the Research Center J¨ulich for seeking out obscure literature. This Ph.D. thesis was sponsored by the Deutsche Forschungsgemeinschaft as part of the DFG priority programme ”Evolution des Systems Erde w¨ahrend des j¨ungerenPal¨aozoikums im Spiegel der Sedimentgeochemie” (Grant Wi 1359). Thanks to many other scientists I met at the DFG-meetings for fruitful discussions. IV Abstract Based on macroscopic fossils, the evolution of land plants is well documented. In contrast, knowledge on the biochemical evolution based on the geochemical char- acterisation of fossil plant material is poorly understood. The investigations of this thesis focus on the composition of extractable organic matter aiming to get insights into biochemical evolution. Additionally, the interdependency between oxygen containing compounds and the non functionalised aromatic hydrocarbons is investigated in detail. A set of 40 samples spanning the time range from Mid- dle/Late Devonian to Permian has been investigated. Criteria for the selection of the samples were: (i) organic matter predominantly originating from terrestrial sources, (ii) having suffered little thermal alteration and (iii) only weak weather- ing. Due to the rarity of Paleozoic samples exhibiting all of these characteristics, the samples had to be sought from numerous locations worldwide. With the excep- tion of two samples, they all belong to the Euramerian flora realm. The vitrinite reflectances of the samples range from 0.32 to 1.80% Rr. Most of them are coaly shales, though a few sediments and two fossils are included in the collection. For the characterisation of compound classes and individual compounds, low molecular weight organic matter was extracted and separated into compound class fractions via liquid chromatography. Five of the gained fractions, the aliphatic hydrocarbons, the aromatic hydrocarbons, the low-polarity and middle-polarity NSO compounds and the acid fractions were investigated in detail. Individual compounds were identified and quantified applying gas chromatography (GC) for the aliphatic hydrocarbons and gas chromatography-mass spectrometry (GC-MS) for the other four compound class fractions. Aliphatic hydrocarbons were minor contributors to the extractable organic matter for most of the samples and yielded little biogenic information. They served to estimate the thermal maturity and the redox potential of the samples. The absence of long chain n-alkanes in most of the immature samples, indicates that cuticular waxes are not an unambiguous characteristic of vascular plants in the Paleozoic. V Among the investigated compound classes, alkyldibenzofurans, alkylphenylnaph- thalenes and benzo[b]naphthofurans were assigned to be terrestrial biomark- ers. While variations in relative amounts of alkyldibenzofurans point to dif- ferent origins of individual isomers, isomers of alkylphenylnaphthalenes and benzo[b]naphthofurans seem to originate from the same sources. It is suggested in this thesis that alkylphenylnaphthalenes may originate from lignans and that benzo[b]naphthofurans are condensation products of an ubiquitous terrestrial source. Alkylnaphthalenes and -phenanthrenes are predominant in all investigated sam- ples, this being typical for terrestrial organic matter of the investigated matu- rity range. Isomers of alkylphenanthrenes showed weaker correlation than iso- mers of alkylnaphthalenes. It is therefore suggested, that alkylnaphthalenes are formed earlier than alkylphenanthrenes with respect to thermal stress and that isomerisation reactions of alkylnaphthalenes therefore proceed prior to those of alkylphenanthrenes. The biogenic significance of individual alkylnaphthalenes and -phenanthrenes is rather complex and is discussed in detail. Based on the data of this thesis the significance of 1,2,7-trimethylnaphthalene as a marker of angiosperms is questionable. In contrast 1,2,8-trimethylphenanthrene could be identified as a compound showing high variations in relative amounts. Thus, it is suggested that the compound originates from tetracyclic triterpenoids of the dammarane type or from plant steroids. Functionalised compounds based on the naphthalene and phenanthrene skeleton are also highly abundant in the low-polarity NSO compound fraction and the acid fraction, this being more pronounced for compounds of the naphthalene type. Both, aldehydes and ketones as well as carboxylic acids strongly correspond to their non-functionalised aromatic counterparts. This strongly indicates that func- tionalised compounds are formed from the aromatic hydrocarbons via oxidation within the investigated maturity range. This is supposed to occur under mild conditions in the case of aldehydes and ketones, while the formation of carboxylic acids is probably forced under thermal stress. By analogy methylfluorenes and methylfluoren-9-ones show strong correlation indicating that alkylfluorenes are easily oxidised in sediments, too. The lowest overall yields of extractable compounds were obtained for the middle- polarity NSO-compound fractions containing alcohols and phenols. This observa- tion was attributed to their depleted thermal stability with regard to the maturity range of the investigated samples. The presence of isoborneol, borneol, fenchyl alcohol, camphor, verbenone, menthol, carvacrol, thymol and menthone in many immature samples expanding the period from the Middle/Late Devonian to Per- mian ages, however, is observed for the first time. This is remarkable due to the VI fact that some of these compounds are strained and their presence probably is of great significance, pointing to the capacity of these ancient terrestrial plants to synthesize these monoterpenes. VII Kurzfassung Die Evolution der Landpflanzen ist durch fossile Uberlieferung¨ auf der makroskopischen Ebene gut dokumentiert. Im Gegensatz dazu ist die zugrun- deliegende biochemische Evolution im Hinblick auf die geochemische Charak- terisierung fossilen Pflanzenmaterials so gut wie nicht erforscht. Diese Arbeit analysiert extrahierbares organisches Material mit dem Ziel, Einblicke in die bio- chemische Evolution der Landpflanzen zu gewinnen. Zus¨atzlich wird der Zusam- menhang zwischen sauerstoffhaltigen Verbindungen und den nicht funktional- isierten aromatischen Kohlenwasserstoffen detailliert untersucht. Es wurden 40 Proben des Zeitraumes Mittleres/Oberes Devon bis Perm analysiert. Kriterien f¨ur die Auswahl der Proben waren: das organische Material sollte (i) haupts¨achlich terrestrischen