Palaeoenvironmental assessment of Westphalian fluvio-lacustrine deposits of Lorraine (France) using a combination of organic geochemistry and sedimentology

Abstract The quality and the quantity of organic carbon preserved in modern and ancient terrestrial sediments is the result of a complex interactions of sedimentological factors, such as in-situ productivity, allochtonous supply of organic matter, oxidation processes, biodegradation and sediment accumulation rates. The study aims at utilizing multidisciplinary information in order to characterize the palaeoenvironment in Westphalian fluvio-lacustrine deposits of the Lorraine Coal Basin (NE France). In this basin, the lack of outcrops is the major difficulty. To compensate for this problem, sedimentology, and molecular geochemistry are combined in order to significantly improve the palaeoenvironmental assessment of the area. Geochemical analyses and sedimentology have been carried out on several core samples of the Saulcy drill hole to evaluate local palaeoenvironmental variability. The lithofacies associations in the Upper Carboniferous of the Lorraine basin suggest an alluvial plain environment without marine incursions. Sedimentological interpretations of the core, as well as comparison with sedimentological models, suggests the recognition of different depositional environments from braided and/or meandering rivers to swamp and lakes. The organic geochemistry is focussed on the recognition of aliphatic hydrocarbons and especially on molecular biomarkers, which provide valuable information about the original organic matter and the transformations that took place during sedimentation and diagenesis. In the Lorraine basin, the botanical variability is high and clearly related to the position of the vegetation communities in the fluvial system. The biomarkers (e.g., diterpanes, steranes) show variations, which can be related to the diversity of this ecosystem. In this study, a reinterpretation of the environmental zonation in the sterane ternary diagram adapted to a fluvio-lacustrine sedimentology is proposed. The correlation between sedimentological and geochemical interpretation permits characterization of various depositional environments. A palaeoenvironment model, relating sediment deposition conditions and organic matter characteristics is proposed.

[1]  M. Iida,et al.  Some new intermediates in microbial side chain degradation of β-sitosterol , 1993 .

[2]  J. Cardoso,et al.  Aliphatic and aromatic hydrocarbons in Candiota coal samples: novel series of bicyclic compounds☆ , 1999 .

[3]  I. Kaplan,et al.  Diterpanes, triterpanes, steranes and aromatic hydrocarbons in natural bitumens and pyrolysates from different mimic coals , 1992 .

[4]  W. Michaelis,et al.  Structure and origin of terpenoid hydrocarbons in some German coals , 1990 .

[5]  K. Peters,et al.  The Biomarker Guide: Interpreting Molecular Fossils in Petroleum and Ancient Sediments , 1992 .

[6]  A. Scott,et al.  Coal and coal-bearing strata as oil-prone source rocks: current problems and future directions , 1994, Geological Society, London, Special Publications.

[7]  A. Scott,et al.  Implications of vegetational change through the geological record on models for coal-forming environments , 1987, Geological Society, London, Special Publications.

[8]  E. J. Gallegos,et al.  Relationship Between Petroleum Composition and Depositional Environment of Petroleum Source Rocks , 1985 .

[9]  C. Diessel.  Coal Bearing Depositional Systems , 1992 .

[10]  A. Scott,et al.  Coal and Coal-bearing Strata: Recent Advances , 1993 .

[11]  J. Hunt,et al.  Geochemistry of aliphatic-rich coals in the Cooper Basin, Australia and Taranaki Basin, New Zealand: implications for the occurrence of potentially oil-generative coals , 1994, Geological Society, London, Special Publications.

[12]  J. Moldowan,et al.  The effect of biodegradation on steranes and terpanes in crude oils , 1979 .

[13]  R. A. Noble,et al.  Maturation effects on absolute biomarker concentration in a suite of coals and associated vitrinite concentrates , 1995 .

[14]  M. Iida,et al.  Microbial degradation of 19-hydroxy-sterol side chains , 1993 .

[15]  C. Fielding,et al.  A coal depositional model for the Durham Coal Measures of NE England , 1984, Journal of the Geological Society.

[16]  P. Faure,et al.  Natural and Laboratory Oxidation of Low-Organic-Carbon-Content Sediments: Comparison of Chemical Changes in Hydrocarbons , 2000 .

[17]  L. Snowdon,et al.  Immature oil and condensate: modification of hydrocarbon generation model for terrestrial organic matter , 1982 .

[18]  W. Meinschein,et al.  Sterols in sediments from Baffin Bay, Texas , 1978 .

[19]  B. Simoneit.  Cyclic terpenoids of the geosphere , 1986 .

[20]  J. Espitalie.  Use of Tmax as a maturation index for different types of organic matter: comparison with vitrinite reflectance , 1986 .

[21]  J. Disnar,et al.  Biological origin of tetracyclic diterpanes, n-alkanes and other biomarkers found in lower carboniferous Gondwana coals (Niger) , 1994 .

[22]  A. Scott,et al.  The oil-generating potential of plants from coal and coal-bearing strata through time: a review with new evidence from Carboniferous plants , 1994, Geological Society, London, Special Publications.

[23]  H. Falcon-Lang.  Fire ecology of a Late Carboniferous floodplain, Joggins, Nova Scotia , 1999, Journal of the Geological Society.

[24]  O. Kural.  Coal : Resources, Properties, Utilization, Pollution , 1994 .

[25]  A. Scott,et al.  The chemical composition of Upper Carboniferous pteridosperm cuticles , 1994 .

[26]  A. Scott.  The earliest conifer , 1974, Nature.

[27]  R. Johns,et al.  Biological markers in the sedimentary record , 1988 .

[28]  J. Volkman,et al.  acyclic isoprenoids as biological markers , 1986 .

[29]  R. Philp.  Geochemical characteristics of oils derived predominantly from terrigenous source materials , 1994, Geological Society, London, Special Publications.

[30]  D. Waples,et al.  Biomarkers for geologists , 1991 .

[31]  Van Krevelen,et al.  Coal--typology, chemistry, physics, constitution , 1981 .

[32]  G. Eglinton,et al.  Organic geochemistry: methods and results , 1969 .

[33]  L. Snowdon.  Resinite — A Potential Petroleum Source in the Upper Cretaceous/Tertiary of the Beaufort-Mackenzie Basin , 1980 .

[34]  B. R. Thomas.  Kauri Resins—Modern and Fossil , 1969 .

[35]  E. E. Bray,et al.  Distribution of n-paraffins as a clue to recognition of source beds , 1961 .

[36]  R. Kagi,et al.  Differences in reactivities of sedimentary hopane diastereomers when heated in the presence of clays , 1988 .

[37]  B. Simoneit,et al.  The molecular composition of ambers , 1988 .

[38]  Pierre Albrecht,et al.  The Hopanoids: palaeochemistry and biochemistry of a group of natural products , 1979 .

[39]  L. V. Dalton.  On the origin of petroleum , 1909 .

[40]  D. Murchison.  Recent advances in organic petrology and organic geochemistry: an overview with some reference to ‘oil from coal’ , 1987, Geological Society, London, Special Publications.

[41]  W. Meinschein,et al.  Sterols as source indicators of organic materials in sediments , 1976 .

[42]  C. Boreham,et al.  Terrestrially sourced oils: where do they exist and what are our limits of knowledge? — a geochemical perspective , 1994, Geological Society, London, Special Publications.

[43]  C. Fielding.  Upper delta plain lacustrine and fluviolacustrine facies from the Westphalian of the Durham coalfield, NE England , 1984 .

[44]  D. Armstrong,et al.  Quantitative and stereoisomeric determination of light biomarkers in crude oil and coal samples , 1998 .

[45]  A. Jessop.  Thermal modeling in sedimentary basins , 1988 .

[46]  P. Ungerer,et al.  Use of kinetic models of organic matter evolution for the reconstruction of paleotemperatures: application to the case of the Gironville Well (France) , 1986 .

[47]  A. Scott,et al.  Upland ecology of some Late Carboniferous cordaitalean trees from Nova Scotia and England , 2000 .

[48]  R. Philp,et al.  Bicyclic sesquiterpenoids and diterpenoids in Australian crude oils , 1981 .

[49]  C. Fielding,et al.  Palaeosols in Westphalian Coal-bearing and red-bed sequences, central and northern England , 1989 .

[50]  D. Welte,et al.  Petroleum Formation and Occurrence , 1989 .

[51]  W. Meinschein,et al.  Sterols as ecological indicators , 1979 .

[52]  M. Nishimura.  The geochemical significance in early sedimentation of geolipids obtained by saponification of lacustrine sediments , 1977 .