classification of huminite iccp system 1994 abstract in the new classification iccp system 1994 the maceral group huminite has been revised from the previous classification iccp 1971 int handbook coal petr suppl to 2nd ed to accommodate the nomenclature to changes in the other maceral groups especially the changes in the vitrinite classification iccp 1998 the new vitrinite classification iccp system 1994 fuel 77 349 358 the vitrinite and huminite systems have been correlated so that down to the level of sub maceral groups the two systems can be used in parallel at the level of macerals and for finer classifications the analyst now has according to the nature of the coal and the purpose of the analysis a choice of using either of the two classification systems for huminite and vitrinite this is in accordance with the new iso coal classification that covers low rank coals as well and allows for the simultaneous use of the huminite and vitrinite nomenclature for low rank coals

biomarker and carbon isotope variation in coal and fossil wood of central europe through the cenozoic abstract carbon isotope analyses of terrigenous organic matter are often used to reconstruct changes in the isotopic composition of upper ocean and atmospheric carbon reservoirs carbon isotope values from tree rings fossil wood and coal matrices have been related to climatic change e g temperature humidity via water use efficiency of land plants in this study we report on carbon isotope analyses on low rank coal deposits of the alpine realm and middle german lignite district covering the early eocene to pliocene time interval fossil wood and extracted wood cellulose from gymnosperms and angiosperms respectively are used for paleoenvironmental reconstructions the trend in 13c is parallel to the carbon isotope record obtained from benthic foraminifera because both data sets sample a common reservoir in the atmosphere the evaluation of the magnitudes of 13c variations of coal caused by environmental change requires the correction of the 13c data due to the effects of different contents of lipids in the organic matter differences in biogeochemical carbon cycling varying contributions of gymnosperms versus angiosperms to peat formation and differences in 13c of atmospheric co2 the resulting carbon isotope record of coal generally co varies with the estimated variability in mean annual temperatures during the tertiary based on paleobotanical data changes in humidity and pco2 may be responsible for deviations between the isotopic trend and the paleotemperature curve during the miocene the obtained temperature coefficient for 13c of c3 plants of about 0 3 c is in agreement with the results of previous studies

compositions sources and depositional environments of organic matter from the middle jurassic clays of poland abstract the comprehensive biomarker characteristics from previously undescribed middle jurassic clays of poland are presented the molecular composition of the organic matter om derived from clays of aalenian to callovian age has not changed significantly through time high relative concentrations of many biomarkers typical for terrestrial material suggest a distinct dominance of om derived from land plants increasing concentrations of c29 diaster 13 17 enes towards the northern part of the basin indicate an increase in terrestrial input this terrestrial material would have originated from the enhanced transport of organic matter from land situated at the northern bank of the basin i e the fennoscandian shield the organic matter was deposited in an oxic to suboxic environment as indicated by relatively low concentrations of c33 c35 homohopanes moderate to high pr ph ratio values an absence of compounds characteristic for anoxia and water column stratification such as isorenieratane aryl isoprenoids and gammacerane as well as common benthic fauna and burrows 18o measurements from calcitic rostra of belemnites suggest that the mean value of the middle jurassic sea water temperature of the polish basin was 13 1 c it is suggested that this mirrored the temperature of the lower water column because belemnites are considered here to be necto benthic the organic matter from the middle jurassic basin of poland is immature this is clearly indicated by a large concentration of biomarkers with the biogenic configurations such as hopanes hop 13 18 enes hop 17 21 enes diasterenes and sterenes the identification of preserved unaltered biomolecules like ferruginol 6 7 dehydroferruginol and sugiol in protopodocarpoxylon wood samples from these sediments present particularly strong evidence for the presence of immature om in the middle jurassic sediments moreover the occurrence of these polar diterpenoids is important due to the fact that they are definitely the oldest known natural products detected in geological samples

stable isotope s c chemostratigraphy and hydrocarbon biomarkers in the ediacaran upper section of sierras bayas group argentina the neoproterozoic sedimentary successions of the sierras bayas group sbg are situated within the tandilia belt buenos aires province argentina the loma negra formation lnf from the upper part of the sbg has been investigated using a combination of inorganic organic and isotopic geochemical methods in order to determine the stable isotope composition of carbonates delta c 13 car delta o 18 car kerogen delta c 13 ker pyrite and carbonate associated sulfur delta s 34 py delta s 34 cas concentrations of major trace and rare earth elements and hydrocarbon distributions were also investigated this data set was used to further the understanding of the interactions between paleo biodiversity and paleoenvironmental conditions for terminal ediacaran post gaskiers shelf deposits the high delta s 34 py values exceeding the coeval delta s 34 cas values in green micritic limestones of the lower lnf may be explained by a combination of different events such as globally low seawater sulfate concentrations an increased rate of bacterial sulfate reduction and a decrease in sulfate levels in the near bottom deepest water layer inherited from glaciations negative ce anomalies in the dark grey micritic limestones of the upper lnf suggest they were deposited under oxidizing conditions however higher concentrations of fe mo zn and ree and the occurrence of authigenic s 34 enriched pyrite suggest that the sediments were maintained under reducing conditions the distributions of hydrocarbon biomarkers e g hopanes maximizing at c 29 are in line with this hypothesis and indicate a diverse microbial community including primary producers such as cyanobacteria e g terminally branched monomethyl alkanes hopanoid distribution phototrophic bacteria e g acyclic isoprenoids c phytane the unsteady delta c 13 car ker values reflect changes in primary biomass due to relative contributions of bacterial microorganisms using different photosynthetic carbon fixation pathways the lowest delta c 13 car ker values coincided with the latest biomarker signal interpreted as the signature of green non sulfur bacteria using a less c 13 fractionation pathway the combined biogeochemical features of the loma negra formation indicated a well stratified water column with oxygenated surface waters oxygen poor bottom waters and anoxic sediments which helped to refine a correlation with the polanco formation from the arroyo del soldado group in uruguay c 2013 elsevier b v all rights reserved

palaeoclimate reconstruction from biomarker geochemistry and stable isotopes of n alkanes from carboniferous and early permian humic coals and limnic sediments in western and eastern europe abstract the type of organic matter om in european carboniferous and permian swamp and lake sediments from the carboniferous and permian was determined using organic petrography rock eval data and biomarker distributions coals deposited in swamps contain humic om formed under oxic conditions boghead coals and black shales deposited in lakes contain a mixture of algal and humic om formed under reducing conditions diterpanes and previous palaeobotanic studies constrain the species of plants living near the lacustrine shore or in the swamp during deposition allowing the palaeoclimate to be inferred during the carboniferous the climate was not always tropical wet as some periods of dryness are evident from the sedimentology palaeobotany and organic geochemistry during the permian the climate was not always tropical dry as some periods of wetness associated with the monsoons are recorded roscher m schneider j w 2006 permocarboniferous climate early pennsylvanian to late permian climate development of central europe in a regional and global context in lucas s g cassini g schneider j w eds non marine permian chronology and correlation vol 265 the geological society of london pp 95 136 the appearance of xerophyte plants from the stephanian was also recorded by way of aromatic hydrocarbons retene for gymnosperms and arborane fernane for cordaites and probably seed ferns cycles of wetness and dryness for europe during the carboniferous and permian are proposed on the basis of comparison of aliphatic and aromatic hydrocarbons d values provided information on the palaeotemperature of the air in the swamps and water in lakes as well as palaeoclimate values of ca 100 seen in the carboniferous coals and permian limnic deposits are indicative of a tropical climate in contrast to a glacial or temperate climate where the values are ca 200 the value for carboniferous coals could result from high evapotranspiration of plants living under a wet tropical climate vs a temperate climate during the early permian the climate was dry tropical for such samples the d values for the n alkanes derived from lacustrine algae were depleted in d relative to the values for the n alkanes derived from terrestrial higher plants attributed to the higher evapotranspiration on land than evaporation from the lake alternatively the xerophytic plants that drifted into the lake via a river could have grown during a dry phase and the autochthonous algae bloomed during a wet phase

sediment transport over an accretional intertidal flat with influences of reclamation jiangsu coast china this paper focuses on the hydrodynamic and suspended sediment transport processes in response to sequential reclamations over the intertidal flat jiangsu coast which used to be one of the widest intertidal flats in china investigations into the sediment transport patterns reveal that net suspended sediment fluxes increased from 102 kg m 1 on the upper intertidal flat to 103 4 kg m 1 on the lower intertidal flat per tidal cycle this variation was caused mainly by the phases of the current velocity suspended sediment concentration ssc local bed geomorphology inundation patterns and extreme weather conditions the longshore component of tidal currents intensifies seaward over the intertidal flat extreme weather conditions e g storms and strong winds were important factors affecting the current velocity structures the intensity of residual currents and the sscs the sscs were characterized by several peaks throughout the tidal cycle these peaks were associated with strong currents combined wave current interactions and intense turbulences due to the initial flood surge furthermore the suspended sediment was finer and contained more clay materials during the flood phase of the tidal cycle than during the ebb fine particles were transported within the upper water column by landward residual currents but coarse particles were transported within the lower water column by seaward residual currents overall residual currents were apt to transport fine grained sediment landward and coarse grained sediment seaward this pattern indicates that the suspended sediment fluxes are highly variable in the water column even for very shallow tidal environments the cross shore component accounted only for a small percentage of the total sediment flux however this part of sediment supply dominated accretion over the intertidal flat the intertidal flat has become narrower and steeper following sequential reclamations a negative feedback process existed to maintain the convex profile shape although the human activities i e reclamation could have modified the natural process the surficial sediment tended to become finer on the mid upper intertidal flat but coarser on the lower intertidal flat following reclamations in response to a reduction in the tidal currents over the intertidal zone and enhancement of wave action over the lower intertidal flat accretion with high rates was maintained by landward transport of sediment in such an accretional system with influences of reclamation the width or slope of the intertidal flat is adjusted continuously before the cease of reclamation the intertidal flat is unable to achieve an equilibrium shape

grain size characteristics of the extant tidal flat sediments along the jiangsu coast china abstract five types of sediments have been identified for the tidal flat deposits along the jiangsu coast 1 fine sand 2 sandy silt 3 silt 4 clayey silt and 5 clay among these the silt deposits including sandy silt silt and clayey silt with median grain diameter of 4 7 are the dominant sediments within this particular intertidal environment they normally have good sorting and are symmetrical or positively skewed and single and or double modal in grain size distribution this type of sediment in terms of grain size characteristics has a very close relationship to its source sediments provided by the two large rivers in the region i e changjiang river and huanghe river the dominant mode for the sediments transported into the environment is suspended load due to the active tidal regime over the region grain size diameters decrease normally from offshore towards onshore in two forms along the jiangsu coast a a step like curve with sharp change occurring at the mud flat and 2 a smooth concave up curve comparing these results with their coastal topographic profiles and sediment dynamic features it is found that form 1 is related to steady accretional progradational tidal flat profiles in the middle part of the coastline and form 2 to erosional stable profiles near the old river deltas the differences in the grain sizes and distribution patterns of the sediments between the northern and the southern parts of the region are mainly due to the difference in sources i e huanghe river sediments dominate the northern part and changjiang river sediments prevail in the southern part except this fluvial control the modern tidal hydrodynamics has also played an important role in the distribution of the coastal and nearshore sediments this is particularly so over the tidal flats rather than in the subtidal offshore area

characterisation of non extractable macromolecular organic matter in palaeozoic coals abstract comprehensive organic geochemical investigations were applied to permian carboniferous and devonian coals the major goal of the investigation was to quantify differences in organic matter composition of the coals on a molecular level and to associate these differences with either i primary composition of the precursor plant material or ii diagenetic processes related to burial and temperature increase or iii evolutionary time trends the pre extracted samples were analysed by means of pyrolytic and chemical degradation techniques as well as ftir spectroscopy additionally rock eval pyrolysis and organic petrography were used to obtain information on the bulk of the coal samples the degradation analysis revealed a wide variety of individual compounds including n alkanes isoprenoids polycylic aromatic compounds fatty acids alkylbenzenes aromatic carboxylic acids and phenols relative concentrations of substances or compound groups were correlated with bulk parameters and age of the samples significant correlations of the chemical data were found out mainly for maturity parameters and maceral composition time depending changes in chemical composition were observed only to a minor extent thus the rapid morphologic evolution of higher land plants in the late palaeozoic is not reflected in a significant way by the chemical composition of the non extractable matter in the coal samples investigated

coal petrological and xylotomical characterization of miocene lignites and in situ fossil tree stumps and trunks from lusatia region germany palaeoenvironment and taphonomy assessment abstract the present paper investigates rank and composition of coal as well as depositional and hydrogeological settings persisting during the stage of peat accumulation and evaluates taphonomy and conditions for the in situ preservation of outstanding fossilized stump and trunks using coal petrological and xylotomical analyses the obtained results are further interpreted and compared with existing literature records lignite samples and fossil wood specimens were collected from the 2nd mfh 2nd miocene seam horizon or its equivalent present at meuro piskowitz and welzow sud open cast mines located in lusatia germany the examined lignite samples indicate low rank coals at lignite or subbituminous rank stage and are characterised by slight dominance of attrinite over textinite ulminite suberinite cutinite porigelinite resinite and corpohuminite macerals waterlogged conditions prevailing in the mire are associated with peat accumulation under anoxic conditions accompanied by low decomposition rates the determined facies indicators suggest a moderate to high as well as low gelification of the organic matter for the meuro and piskowitz open cast mines respectively in meuro open cast mine the prevalence of herbaceous plant in a mire or a bacterial fungal degradation of woody plant tissues can be envisaged whereas in the piskowitz open cast mine it is suggested that peat formed in a wet forest mire environment with a limited oxygen supply and a relatively low bacterial fungal degradation the studied fossil wood specimens revealed the presence of quasisequoioxylon piskowitzense preserved as an in situ fossilized stump as well as taxodioxylon cryptomerioides and sciadopityoxylon wettsteinii species preserved as fossilized trunks the examined species belong to the families of cupressacea sciadopityaceae and cupressaceae li sensu lato the taphonomy of the in situ fossilized stump and trunks can be explained by nutrient and oxygen poor oligotrophic mires distinguished as raised bogs and suggesting generally anoxic conditions during middle to late miocene climate transition

aliphatic and diterpenoid hydrocarbons and their individual carbon isotope compositions in coals from the liaohe basin china abundant tricyclic diterpanes i e pimarane dehydroabietane and simonellite and tetracyclic diterpanes e g phyllocladane were detected in coal samples from the third member of the shahejie formation lower eogene liaohe basin china gas chromatography isotope ratio mass spectrometry gc irms analyses show that the carbon isotopic composition of terrigenous tricyclic and tetracyclic diterpenoid hydrocarbons are about 4 6 enriched in 13c compared to n alkanes in the same samples in addition the pimaranes and phyllocladane have comparatively narrow stable carbon isotopic compositions among the different samples with a slightly wider range in 13c compositions for the abietanes i e abietane dehydroabietane and simonellite the n alkanes and triterpenoids reflect the 13c compositions of higher plant wax

suspended sediment transport processes on tidal mud flat in jiangsu province china the intertidal mud flat in jiangsu province is an open or semi open tidal flat with a moderately high tidal range this paper analyses characteristics of tidal current and suspended sediment concentration on the intertidal flat comparison is then made with characteristics on the intertidal flat of the dutch coastline wadden sea and similar areas the suitability and limitations of applying the lag mechanism to an open or semi open macrotidal flat is examined residual water and sediment circulation on the intertidal flat show they can be divided into a series of longshore cells which form individual hydrodynamical sedimentary units

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

temporal and spatial variation in intertidal sedimentation rates sediment deposition and erosion rates are reported for an intertidal zone in the burry inlet south wales measured deposition rates over the salt marsh are compared with deposition rates calculated from observed suspended sediment concentrations notably it is concluded that residual turbulence at slack water should not be discounted when calculating deposition rates grain size distributions of suspended sediments over the marsh surface during flood and ebb tides contrast with the grain size distribution of deposited marsh sediments the latter being significantly coarser these data in conjunction with mass budget calculations are used to relate total annual deposition and sediment supply by tidal action during settled meteorological periods the analysis suggests that episodic storm induced sediment transport is probably an important mechanism for introducing coarse sediment on to the marsh surface finally it is noted that seasonal reworking of the sandy non cohesive sediments may be related to variations in the intensity of wave breaking throughout the year

nuclear magnetic resonance studies of ancient buried wood i observations on the origin of coal to the brown coal stage various wood fragments buried in sediments under anaerobic conditions for from 450 yr to approximately 8 myr have been examined by solid state 13c nuclear magnetic resonance cellulose and other carbohydrates the major components of holocene wood have been shown to be gradually hydrolyzed or otherwise lost under the conditions of burial lignin structures however are preserved relatively unchanged and become concentrated by difference as the carbohydrates disappear thus a fragment of coalified wood isolated from a miocene brown coal was found to be still composed of approximately 75 lignin and 25 cellulose on the basis of our observations we suggest that coalification of woody tissue progresses directly from lignin to coal and that such coalification may be retarded until most of the cellulose disappears

organic geochemistry of duckmantian pennsylvanian coals from the ruhr basin western germany abstract the molecular composition of 58 duckmantian ruhr coals and adjacent sedimentary rocks has been analyzed using organic geochemical investigations representing a maturity range from 0 74 to 0 98 vitrinite reflectance in addition eight samples of higher maturity 1 46 to 3 55 vitrinite reflectance were studied for comparison the composition of coals depends primarily on plant input into the peat swamps but also to a large extent on thermal maturity several maturity related parameters have been applied in this study such as mpi dmai and diverse hopanoid based maturity ratios especially diamantane based parameters proved to be excellent for characterizing high rank samples whereas hopane and phenanthrene based parameters are well suited for the lower maturity range various specific biomarkers reflect the composition of the duckmantian coals concerning the floral differences and floral shift during the westphalian the dominating n alkanes hopanes and bicyclic sesquiterpanes show only marginal differences and reveal a quite homogenous floral composition within the six coal seams tetracyclic diterpanes as approved markers for modern as well as paleozoic conifers and pre gymnosperms have been identified in all six coal seams but in low concentration one order of magnitude lower than bicyclic sesquiterpanes a slight increase of the tetracyclic diterpane ent beyerane in the younger seams indicates an increase in abundance of pre gymnosperms cordaites during the duckmantian significantly increased proportions of diverse compounds like bicyclic sesquiterpanes eudesmane or tetracyclic terpanes clearly testify an origin from higher land plants the major part of the duckmantian coal swamps biomass with its vitrinite rich coals originated presumably from barks of arborescent lycopods high concentrations of hopanes mirror the input of bacterial organic matter and a strong microbial reworking of the deposited terrestrial plant organic matter

mechanisms underlying the regional morphological differences between the northern and southern radial sand ridges along the jiangsu coast china abstract radial sand ridges rsrs spread in a fan shaped pattern over the seabed of the southern yellow sea along the jiangsu coast china with pronounced differences between the northern and southern channel shoals indicated as ncs and scs respectively a depth averaged nested numerical model is employed to analyze the tidal hydrodynamics and sediment dynamics of the rsrs model results show considerable regional differences in terms of tidal current vector ellipses eight shaped ellipses are typical in the ncs where rotational tidal waves dominate while the scs are characterized by egg shaped ellipses because of the dominance of progressive tidal waves sand ridges tend to be elongated and straight in the ncs while short and dincontinuous in the scs numerical lagrange particles released near the ridges in the ncs tend to travel across the crest of the ridges rather than move around them as observed in the scs consistently the patterns of sediment convergence and divergence indicate that suspended sediments converge over the whole xiaoyinsha ridge located in the ncs while converge to the two sides of the hetunsha ridge located in the scs model results also highlight the importance of initial sediment compositions in determining patterns of the net sediment fluxes the suspended sediment concentration ssc time series during one tidal cycle may show single or double peaks depending on the grain size and the related lag effect bed load transport is much smaller than suspended load so sediment compositions should be carefully considered when simulating the ssc field and the hydrodynamic of the morphological evolution of the rsrs at the regional scale overall this study suggests that the ncs and scs may be treated as two relatively independent geomorphological systems characterized by different tidal flows and sediment compositions

tidal hydrodynamics and fine grained sediment transport on the radial sand ridge system in the southern yellow sea abstract the large radial sand ridge rsr system located in the southern yellow sea off the jiangsu coast is characterized by a radial current field and high suspended sediment concentrations sscs significant rectilinear currents are present over the northern sand ridge area whereas rotary currents prevail over the southern area the transition between the two being dominated by a locally generated trapped wave observations undertaken in 2006 and 2007 indicate a seasonal pattern in the ssc and associated dynamic characteristics the results of a calibrated hydrodynamic model show that the m2 tide dominates the rsr area the maximum tidal amplitude in the core region close to land being approximately 2 m an amphidromic point is located some distance north of the rsr off the abandoned yellow river mouth 121 686 e 34 6 n specifically the eulerian and lagrangian residual currents flow southward in both summer and winter whereas the stokes drift is directed southward in the north and northward in the south moreover in deep water the lagrangian residual current is mainly determined by the eulerian residual current whereas it is strongly influenced by the stokes drift in shallow water the seasonal variation in the residual current in the southern yellow sea is a good indicator for the location of the yellow sea warm current yswc in both summer and winter measurements show that a ssc peak appears off the abandoned yellow river delta in response to the strong currents and plentiful supply of fine grained sediment from coastal erosion another ssc peak lying close to the north branch of the changjiang river mouth is related to the abundant suspended sediment supplied by the river seasonal variations in ssc are observed in the study area maximum average values and widest diffusion from land occurring in winter this being contrasted by minimum mean values in summer sensitivity experiments demonstrate that the main factor influencing the distribution of ssc is the tide while river discharge wind and wave effects are small and very localized to explain the seasonal variation in ssc the role of hydrodynamics initial conditions and temperature are tested in the model the results show that the hydrodynamics play a significant role whereas the initial conditions only have a minor regional influence temperature on the other hand is also shown to greatly influence the seasonal variation in ssc because of substantial changes in the viscosity of the water and the erosion shear stress the modeled results are used to calculate sediment fluxes which are shown to be consistent with the lagrangian residual current pattern while wind waves can significantly change the fluxes in winter bed elevations change substantially on a monthly time scale in general the deep channels are undergoing erosion while the shallow ridges and coastal tidal flats are accreting the net sediment transport being directed towards the coastal tidal flat and the changjiang yangtze river subaqueous delta

in situ preservation and paleoenvironmental assessment of taxodiacea fossil trees in the bukkalja lignite formation bukkabrany open cast mine hungary abstract in summer 2007 sixteen taxodium tree trunks were found in situ standing position in the bukkabrany open cast mine the fossil trees were exposed during the excavation of the overburden layers of the bukkalja lignite formation bl the bukkabrany discovery is a global novum because the trees are very well preserved but not fossilized that makes the most detailed and direct analysis feasible in spite of the 7 8 million years passed the actual site and the host formation is rather intact lacking tectonic deformations deeper burial and or dewatering during uplift organic petrology of tree trunks and sedimentology of the overburden sands are the subjects of this study the extremely good preservation of fossil trunk tissues presence of high amount of cellulose and moisture content along with the slightly gelified state of the wood and the lack of deformation indicate that there was only limited alteration during the early diagenesis chemical investigation of standing trunks fossil driftwood nearby the late miocene trees and the fossil woods in the underlying lignite have revealed that their cellulose and total phenol concentrations were significantly lower than in intact recent trees applied for reference yet their preservation levels were quite high also proving that the chemical degradation of the fossil wood tissues had not been taken place extensively in the mire and the trees remained exceptionally well preserved sudden burial of the trees by strand plain sand beds indicates flooding by heavy storms or tsunamis which interrupted and terminated the peat formation and preserved the trunks from later oxidation and biodegradation

palaeoenvironmental implications of coal formation in dobrudzha basin bulgaria insights from organic petrological and geochemical properties abstract the dobrudzha basin in northeast bulgaria contains 86 coal seams distributed within three coal bearing formations of late carboniferous age this study presents the organic petrological and geochemical characteristics of coals from the makedonka and krupen formations containing some of the most prominent coal seams these were characterized by means of proximate and rock eval analyses vitrinite reflectance measurements organic petrography and gcms analysis in order to establish variations in vegetation and depositional settings based on random vitrinite reflectance avg 0 7 r r and toc contents avg 80 daf the coals can be classified as low rank bituminous high volatile b c low tmax values avg 430 c further indicate a low degree of organic matter maturity the low to moderately high ash yields together with the presence of shaly partings and generally low sulfur contents are consistent with peat formation in a fluviatile sedimentary environment petrographic analysis reveals complex maceral composition with abundant liptinite and inertinite the predominance of detrovitrinite and the almost complete lack of strongly gelified macerals argue for enhanced humification of the plant tissues and peat formation in relatively dry environments above water table the distributions of n alkanes diterpenoids and steranes indicate that the organic matter originated from terrestrial vascular plants the high pristane phytane ratios point to peat deposition under oxic conditions low concentrations of hopanes argue for limited bacterial degradation of the organic matter possibly due to low ph conditions during peatification the presence of tetracyclic diterpanes and their aromatic counterparts is attributed to pre gymnosperm cordaitean input the existence of cordaiteans although as minor component of the palaeovegetational communities is further evidenced by the presence of trace amounts of aromatic arborane fernane derivatives in almost all studied samples the occurrence of combustion derived pahs in all studied samples is consistent with the abundant inertinite and indicates frequent forest fires during peat formation

hydrocarbon biomarkers from ordovician sediments and the fossil alga gloeocapsomorpha prisca zalessky 1917 numerous ordovician oils worldwide are known to show unusual and distinctive distributions of hydrocarbons which it has been suggested are derived from a unique benthonic mat forming non photosynthetic prokaryotic organism gloeocapsomorpha prisca zalessky 1917 which is the major contributor of organic matter organic matter rich sediments from the canning and amadeus basins of australia known to contain g prisca fossils and to have the characteristic predominance of odd carbon number c13 c19 n alkanes were investigated to determine other hydrocarbon distributions sediments from both basins contained abundant n alkylcyclohexanes with odd carbon number predominance c13 c19 and methyl n alkylcyclohexanes c14 c20 which in immature sediments showed an even carbon number predominance the isomer distribution of these latter compounds was determined by direct comparison with synthetic standards the sediments from both basins also contained very similar distributions of steranes and pentacyclic triterpanes and the derived kerogens had a characteristically light carbon isotope signature pyrolysis of a g prisca rich kerogen yielded a hydrocarbon mixture with a similar composition to the sediment extract except that there was a marked increase in the relative abundance of pristane phytane alkylcyclohexanes steranes and hopanes relative to n alkanes we argue on the basis of the geological geochemical and palynological data that g prisca was probably planktonic photosynthetic and very possibly eukaryotic and that the striking character of ordovician oils and sediments derive from bacterial and other diagenetic imprints superimposed on the primary signature of this organism

geochemical constraints on the provenance of surface sediments of radial sand ridges off the jiangsu coastal zone east china abstract the jiang harbor centered radial sand ranges rsrs off the jiangsu coast are the largest in the yellow sea however the provenance of the rsrs remains controversial in this study we compare major and trace element geochemistry together with grain size and main mineral composition in carbonate free sediments from rsrs and potential sources onshore and offshore rsr sediments have different grain size characteristics onshore rsr sediments have mean grain sizes of 2 tio 2 li and partly in cs zn and some high field strength elements y zr nb pb and th while depleted in other elements offshore rsr sediments are complicated in geochemical compositions some of them have very high contents of high field strength elements and others are similar to onshore rsr sediments onshore and offshore rsr sediments have different controlling factors of geochemical compositions onshore rsr sediments are influenced by clay size minerals whereas offshore sediments are controlled by heavy minerals the identification of zr nb and ti zr vs k rb shows that onshore and offshore rsrs seem to have similar sources their differences in grain size are a result of hydrodynamic sorting the identification of elemental ratios reveals that sources of rsr sediments are variable in space and time and the inputs of the chinese rivers especially the old yellow river and the yangtze river are still dominant but the effect of the korean field cannot be neglected our findings also demonstrate the potential of elemental ratios such as zr nb and k rb as tracer pairs for provenance of sediments in the yellow sea

biomarkers and aromatic hydrocarbons in bituminous coals of upper silesian coal basin example from 405 coal seam of the zaleskie beds poland abstract this paper presents the geochemical characteristics of hard coals from the 405 coal seam found in several mines in the upper silesian coal basin poland the coals classifying as of medial coalification types d and c and as para and orthobituminous coals show variable technical chemical and petrographic properties vitrinite reflectance values range from 0 65 to 1 24 cdaf from 79 2 to 88 3 wt and vdaf from 23 7 to 37 4 wt maceral composition in all of the coals studied is dominated by vitrinite macerals 43 5 74 0 gas chromatography mass spectrometry was applied to assess organic matter sources and ranks using several biomarker and aromatic hydrocarbon parameters distributions of n alkanes acyclic isoprenoids diterpenoids steranes and triaromatic steroids indicate that the organic matter in the coals analysed is derived mostly from terrestrial vascular plants the biogenic organic matter was deposited mostly in an estuarine deltaic environment with a normal to low water level in a few cases a marine lagoonal or paludal environment is possible tetracyclic diterpanes such as phyllocladanes and kauranes indicators of the podocarpaceae and araucariceae families are explained by proposing input of organic matter deriving from voltziales plants which may have been able to synthesise these compounds biomarker and aromatic hydrocarbon parameters of thermal maturity in the coals show a clear correlation to vitrinite reflectance values and carbon content indicating degrees of thermal maturity in the range from early to advanced catagenesis frictional heat related to the klodnica fault movement caused aberrations in values of aromatic hydrocarbon maturity parameters in coals sampled

organic geochemistry of sediments in new zealand part i a biomarker study of the petroleum seepage at the geothermal region of waiotapu abstract the saturated hydrocarbons from the oil seepage at waiotapu in new zealand were examined by gc and gcms techniques of molecular fingerprinting the petroleum was characterised by a high ratio of phytane nc18 2 37 and low ratios of pr ph 0 64 and saturates aromatics 0 60 this study revealed that the oil was derived from terrigenous organic matter and it had neither migrated from its source nor suffered biodegradation the source rocks were deposited under anoxic conditions and these rocks lay within pleistocene sediments which were immature with respect to oil generation the location of the source rocks within a geothermal field had accelerated the generation of petroleum since the source rocks would have been too young and shallow to generate petroleum in the absence of geothermal energy

hydrocarbon biomarkers in the topla mežica zinc lead deposits northern karavanke drau range slovenia paleoenvironment at the site of ore formation the mississippi valley type zinc and lead deposits at topla 250 150 metric tons t of ore grading 10 wt zn and 3 3 wt pb and me ica 19 million metric tons mt of ore grading 5 3 wt pb and 2 7 wt zn occur within the middle to upper triassic platform carbonate rocks of the northern karavanke drau range geotectonic units of the eastern alps slovenia the ore and host rocks of these deposits have been investigated by a combination of inorganic and organic geochemical methods to determine major trace and rare earth element ree concentrations hydrocarbon distribution and stable isotope ratios of carbonates kerogen extractable organic matter and individual hydrocarbons these data combined with sedimentological evidence provide insight into the paleoenvironmental conditions at the site of ore formation the carbonate isotope composition the ree patterns and the distribution of hydrocarbon biomarkers normal alkanes and steranes suggest a marine depositional environment at topla a relatively high concentration of redox sensitive trace elements v mo u in the host dolostones and ree patterns parallel to that of the north american shale composite suggest that sediments were deposited in a reducing environment anoxic conditions enhanced the preservation of organic matter and resulted in relatively higher total organic carbon contents up to 0 4 wt the isotopic composition of the kerogen 13 c kerogen 29 4 to 25 0 15 n kerogen 13 6 to 6 8 suggests that marine algae and or bacteria were the main source of organic carbon with a very minor contribution from detrital continental plants and a varying degree of alteration extractable organic matter from topla ore is generally depleted in 13 c compared to the associated kerogen which is consistent with an indigenous source of the bitumens the mineralization correlates with 15 n kerogen values around 0 per mil 13c depleted kerogen 13c enriched n heptadecane and relatively high concentrations of bacterial hydrocarbon biomarkers indicating a high cyanobacterial biomass at the site of ore formation abundant dissimilatory sulfate reducing bacteria feeding on the cyanobacterial remains led to accumulation of biogenic h 2 s in the pore water of the sediments this biogenic h 2 s was mainly incorporated into sedimentary organic matter and diagenetic pyrite higher bacterial activity at the ore site also is indicated by specific concentration ratios of hydrocarbons which are roughly correlated with total pb plus zn contents this correlation is consistent with mixing of hydrothermal metal rich fluids and local bacteriogenic sulfide sulfur the new geochemical data provide supporting evidence that topla is a low temperature mississippi valley type deposit formed in an anoxic supratidal saline to hypersaline environment a laminated cyanobacterial mat with abundant sulfate reducing bacteria was the main site of sulfate reduction

fossil wood from the middle cretaceous moreno hill formation unique expressions of wood mineralization and implications for the processes of wood preservation abstract the cretaceous turonian moreno hill formation of west central new mexico provides an opportune isotaphonomic setting to study wood preservation because both carbonized and mineralized wood are commonly found within the same sediments and often within individual specimens petrographic reflectance maceral and chemical analyses were used to compare and characterize mineralized and carbonized wood from the study site to investigate biases which influence mode of preservation coal in the form of coal inclusions is the most common form of fossil wood and mineralized wood is also widespread in the formation two striking specimens of in situ coalified stumps are particularly informative because each includes a mineralized ring that appears to represent the former location of sapwood most of the mineralized samples are primarily composed of quartz but a few specimens are predominantly mineralized with apatite calcite is present in charcoal samples where it permineralized but never replaced organic carbon this study points to two key factors that influence mineralization wood permeability and the chemical alteration of the wood prior to incorporation into the sediment the patterns of mineralization are consistent with hypothesized microbial involvement in the mineralization process the coexistence of coal and mineralized tissues in some samples suggests that the processes of silicification and phosphatization co occurred with coalification and that these processes are competitive within individual pieces of wood as such various stages of wood degradation have been preserved in mineralized samples from the moreno hill formation the study suggests that coal inclusions and mineralized wood coal associations may also be common in other ancient sediments even though weathering may obscure their presence such information is important for paleoecological and paleoenvironmental studies which utilize the occurrence of fossil wood to help reconstruct floral composition or climatic conditions

biomarker and stable carbon isotope systematics of fossil wood from the second lusatian lignite seam of the lubstow deposit poland abstract decay of fossil wood gelification collected from the middle miocene 2nd lusatian lignite seam at the lubstow open cast mine poland is characterised by its maceral variety fluorescence intensity and cellulose content cellulose decomposition leads to lower molar h c ratio values of the organic matter as indicated by higher total organic carbon toc content of samples characterised by low cellulose content biochemical formation of hydrocarbons in the wood due to enhanced microbial activity is evidenced by higher hydrocarbon content in the extracts higher relative proportions of n alkanes and hopanoids are observed in the hydrocarbon fractions of wood remains characterised by low cellulose yield the results provide evidence for the formation of these compounds during biogeochemical transformation of organic matter hopanoid contents are considered to reflect the activity of aerobic bacteria and or fungi because of enhanced perylene content in the hydrocarbon fractions from gelified wood samples fungi are considered as the major precursor carriers of this polycyclic aromatic hydrocarbon the results provide evidence that biomarker composition of fossil wood can be used to trace biochemical transformation processes chemotaxonomical classification of fossil wood fragments as gymnosperms most probably species of the coniferales families taxodiaceae cupressaceae are based on the molecular composition of terpenoid hydrocarbons and a mean 13 c value of 24 5 depletion of gelified samples in 13 c as compared to ungelified wood is caused by the effect of progressive decomposition of cellulose the data indicate that cellulose 13 c data mean 13 c 20 8 are also affected by wood decomposition and so only samples with comparable cellulose content should be used for the reconstruction of environmental changes inter species as well as intra plant variation in carbon isotope differences and of decay resistance between cellulose and lignin have to be taken into account

lipid biomarkers in the zoige hongyuan peat deposit indicators of holocene climate changes in west china abstract lipid biomarkers extracted from a peat core obtained from the northeast edge of the tibetan plateau have provided a 13 kyr record of regional climate change a period of warmer climate corresponding to the holocene optimum between 9 ka and 5 ka is evident in greater alteration of n alkanoic acids and n alkanols and in the appearance of biomarkers indicative of greater microbial activity concomitant increases in local precipitation that raised the water level of the peat bog are recorded by increases in the proportions of c23 and c25 n alkanes that are mainly derived from submerged floating plants alternations in submergent and emergent plant n alkane proxies reveal multi decimeter scale rises and falls in the bog water level that relate to variation in precipitation on the tibetan plateau during the holocene major low water level events occurred around 12 6 11 3 10 7 9 4 8 3 6 0 4 5 3 1 2 1 and 1 0 ka these events correlate well with cold dry events recorded in same region from other climatic proxies that reflect millennial scale holocene instability in the asian monsoon system our biomarker results also indicate that peat accumulation and preservation on the tibetan plateau are more sensitive to variability in monsoonal precipitation than in annual temperature

geochemical characteristics of tertiary coal bearing source rocks in xihu depression east china sea basin abstract this study aims at investigating hydrocarbon generation potential and biological organic source for the tertiary coal bearing source rocks of pinghu formation middle upper eocene in xihu depression east china sea shelf basin another goal is to differentiate coal and mudstone with respect to their geochemical properties the coal bearing sequence has a variable organofacies and is mainly gas prone the coals and carbonaceous mudstones in comparison with mudstones have a higher liquid hydrocarbon generation potential as reflected by evidently higher hi values averaging 286 mg hc g c and h c atomic ratios round 0 9 the molecular composition in the coal bearing sequence is commonly characterized by unusually abundant diterpenoid alkanes dominant c29 sterane over c27 and c28 homologues and high amount of terrigenous related aromatic biomarkers such as retene cadalene and 1 7 dimethylphenanthrene indicating a predominantly terrigenous organic source the source rocks show high pr ph ratios ranging mostly from 3 5 to 8 5 and low mdbts mdbfs ratios

structure and origin of terpenoid hydrocarbons in some german coals abstract hydrocarbon extracts of coal samples from major coal fields in west germany have been investigated by gas chromatography mass spectrometry gc ms the samples are of carboniferous and tertiary age and derive from limnic and paralic environments the saar district the ruhr area and the lower rhine basin differences in facies maturity and age reflected in the distribution patterns of the extracted alkylcyclohexanes an unexpected occurrence of cyclic diterpenoid hydrocarbons in some samples of carboniferous age has been found the tetracyclic compounds mainly show phyllocladane type structures and can serve as source indicators hydrocarbons obtained from chemical degradation of the macromolecular material of the samples also revealed phyllocladane type compounds which are normally associated to resins of modern and extinct familes of conifers origin and structural variations of this class of hydrocarbons are discussed in terms of maturity and palaeobotanical implications

petrology and organic geochemistry of the lower miocene lacustrine sediments most basin eger graben czech republic abstract thirty samples of the lacustrine sediments from three localities of the most basin including coal samples were studied by petrological and organic geochemical methods the consistent results indicate the relatively stable surface development of the sediments in the environment of the holesice lom and osek members biological material with contribution of microbial activity participated in the storing which led to the formation of clayey coal in the results of the chemical composition dominated sesqui diand triterpene compounds completely different sediments of libkovice member contained low proportions of small organic particles dispersed in the sediment in the extracts of these samples prevailed hopanes perylene and sulphur after the action of microorganisms the base of the organic fraction also formed remains of terrestrial plants and liptinite macerals especially alginite liptodetrinite and bituminite that are typical for lacustrine sediments

a short term establishment of forest fen habitat during pliocene lignite formation in the ptolemais basin nw macedonia greece the intermontane basin of ptolemais is part of a major tectonic trench located in nw greece and includes around 65 of greek coal reserves the upper xylite layer uxl is a distinct lignite layer being 3 6 m thick and outcropping in the upper part of the pliocene lignite bearing sequence at the notio field and tomeas eksi mines of ptolemais compared with the xylite rich lithotypes the matrix lithotypes within uxl contain more ash micropetrographic studies suggest that the upper xylite layer is rich in huminite 90 textinite dominates in the xylite rich lithotypes while attrinite dominates in the matrix lithotypes the liptinite content is 10 while inertinite rarely occurs palaeobotanical determination revealed that the xylite rich coal originated from coniferous vegetation specifically from glyptostrobus europaeus the occurrence of g europaeus as a coal forming element is significant because though this kind of vegetation was common in many greek coals of miocene age this is the first time it has been recorded from the pliocene this study suggests that the upper xylite layer is autochthonous according to coal facies diagrammes peat accumulated under pure telmatic conditions in a relatively wet forest fen both herbaceous and arboreal vegetation contributed to peat formation

organic geochemistry across the permian triassic transition at the idrijca valley western slovenia abstract bulk and molecular stable c isotopic compositions and biomarker distributions provide evidence for a diverse community of algal and bacterial organisms in the sedimentary organic matter of a carbonate section throughout the permian triassic p tr transition at the idrijca valley western slovenia the input of algae and bacteria in all the upper permian and lower scythian samples is represented by the predominance of c15 c22 n alkanes odd c number alkylcyclohexanes c27 steranes and substantial contents of c21 c30 acyclic isoprenoids the occurrence of odd long chain n alkanes c22 c30 and c29 steranes in all the samples indicate a contribution of continental material the decrease of corg and ccarb contents increase of rock eval oxygen indices and 13c enrichment of the kerogen suggest a decrease in anoxia of the uppermost permian bottom water the predominance of odd c number alkylcycloalkanes c27 steranes and c17 n alkanes with 13c values 30 and 13c enrichment of the kerogens in the lowermost scythian samples are evidence of greater algal productivity this increased productivity was probably sustained by a high nutrient availability and changes of dissolved co2 speciation associated to the earliest triassic transgression a decrease of corg content in the uppermost scythian samples associated to a 13c depletetion in the carbonates up to 4 and individual n alkanes up to 3 4 compared to the upper permian samples indicate lowering of the primary productivity algae cyanobacteria and or higher degradation of the organic matter

aliphatic and aromatic biomarkers from carboniferous coal deposits at dunbar east lothian scotland palaeobotanical and palaeoenvironmental significance carboniferous visean coals from dunbar east lothian scotland contain well preserved miospore and megaspore assemblages suggesting a lycopod dominated forest ecosystem with some ferns sphenopsids and pteridosperms the low rank of the coals and the well defined microflora permit assessment of the palaeoenvironmental significance of lipid biomarkers during the early carboniferous rock eval petrographic and lipid analyses indicate a fully terrestrial depositional environment although we also present and discuss a wide diversity of other lipid biomarkers alkanes hopanoids steroids we focus on the terrestrial derived biomarkers combustion derived pahs pyrene fluoranthene benzo a anthracene chrysene and triphenylene indicate the occurrence of forest fires in the study areas during early carboniferous times alkyldibenzofurans are considered to derive from lichen biomass retene cadalene simonellite tetrahydroretene and kaurane are poorly specific and can derive from a variety of early palaeozoic land plants abietane phyllocladane ent beyerane and 4 h eudesmane as well as bisnorsimonellite diaromatic totarane diaromatic sempervirane and 2 methylretene however as yet had only been reported from conifers which do not appear in the fossil record until the late carboniferous within the lower carboniferous forest ecosystem arborescent lycopsids and pteridosperms are proposed as alternative sources for these compounds

stump horizon in the bilina mine most basin czech republic gc ms optical and electron microscopy in identification of wood biological origin article i nfo numerous coalified tree stumps remained preserved in situ in the so called stump horizon the palaeontologic horizon no 31 which represents clayey overburden of themain coal seam in the bilina open cast mine in the most basin czech republic the petrological and chemical composition palaeobotanical origin and preservation of 24 selected tree stumps were studied by optical and scanning electron microscopy and gas chromatography mass spectrometry gc ms composition of the fossil wood is dominated by ulminite particularly texto ulminite b textinite forms up to 38 vol in the decomposed tree stumps corpohuminite dominates in bark and root tissues partly gelified and deformed woody tissuescontain both corpohuminite and resinite fillings randomreflectance of ulminite ranges from 0 33 to 0 39 and carbon content from 49 wt to 78 wt samples represent pure woody material with small admixtures of clay minerals siderite and very rare pyrite observations by scanning electron microscopy revealed various levels of deformed secondary xylem with more or less swollen cell walls conspicuous tracheids uniseriate rays of a different height and round or cylinder like resin or corpohuminite bodies according to our results and other published data the wood might belong to glyptostroboxylon and taxodioxylon genera that are supposed to belong to glyptostrobus and quasisequoia plants respectively representatives of the coniferous family cupressaceae the biomarker composition in the extracts of the fossil wood includes sesquiterpenoids cedrane drimane eudesmane diterpenoids abietane fichtelite 16 h phyllocladane and their degraded compounds the terpenoids are derived from precursors produced by the source plants and microorganisms the terpenoid signatures support a relationship to the cupressaceae family with input of microbial species these characteristics were identical for all studied samples significant variations have been observed in sesquiterpenoid cedrane and diterpenoid 16 h phyllocladane contents

biomarker composition of higher plant macrofossils from late palaeozoic sediments the main objective of the present study was to clarify if the fernane derivatives 5 methyl 10 4 methylpentyl des a 25 norferna 5 7 9 triene math 25 norferna 5 7 9 triene maph 24 25 dinorferna 1 3 5 7 9 pentaene daph 1 and iso 25 norferna 1 3 5 7 9 pentaene daph 2 can securely be assigned to one of the three previously proposed source plant groups from some euramerican upper carboniferous coals uppermost westphalian and stephanian for this purpose remains of conifers cordaites and pteridosperms were isolated from core and outcrop material from different euramerican coal basins e g saar nahe basin blanzy montceau basin results show that math maph daph 1 and daph 2 were present in all extracts of cordaite remains in the sediments surrounding the cordaite macrofossils the compounds were either not detectable or have been found only in comparatively small amounts obviously due to impregnation originating from imbedded cordaites contrarily the compounds were not detected in the extractable organic matter of conifer macrofossils derived from the saar nahe basin from bletterbach south tyrole italy and from frankenberg hessen germany the same is true for remains of horsetails calamites giant club mosses lepidodendron and sigillaria and ferns pecopteris from the saar nahe basin which have been studied for comparison the compounds were also lacking in the extractable organic matter of pteridosperms like alethopteris dicroidium lescuropteris macroneuropteris and neuropteris but were detected in minor amounts in some odontopteris remains from the blanzy montceau basin france however the sediments surrounding the odontopteris macrofossils yielded even higher concentrations of the compounds for this reason the odontopteris macrofossils were most likely impregnated by migrating fernane derivatives from the sediment which were possibly originally originating from cordaite remains therefore cordaites can most probably be considered as one and possibly the only biological source of the precursor molecules of the fernane derivatives math maph daph 1 and daph 2 in the upper carboniferous coal basins

abundant tetracyclic terpenoids in a middle devonian foliated cuticular liptobiolite coal from northwestern china cuticular liptobiolite coal defined by its dominant cutinite is rare and only known in a few regions of the world an occurrence of this type of coal found in the devonian of the hefeng basin xinjiang northwestern china is described for the first time by organic petrography and biomarker analysis the cuticular liptobiolite has distinct sheet like layers and thus splits easily into leafy laminae which are segregated during weathering forming a so called paper coal it is comprised dominantly of cutinites 75 vol on a mineral free basis with minor vitrinites 20 lycopsids are suggested to be the dominant coal forming plants the aliphatic fractions of these samples contain only small amounts of n alkanes and common biomarkers such as steranes and hopanes tetracyclic diterpanes cnh2n 6 with mainly beyerane and atisane skeletons are the dominant constituents the abundant tetracyclic diterpanes present in this and other devonian cuticle rich coals indicate that their parent natural product precursors occurred abundantly in the early vascular land plants of the devonian i e lycopsid and psilopsid species it seems that these early land plants secreted massive amounts of resins from their vascular tissues coating their cuticle surfaces to protect against water evaporation massive cuticle accumulation in the middle devonian likely resulted from a simple assemblage of unique early land plants

magnetic and geochemical evidence of yellow and yangtze river influence on tidal flat deposits in northern jiangsu plain china abstract the formation of a broad tidal flat along the coast of the northern jiangsu province of china depends largely on the sediment supply from the yellow and yangtze rivers although the relative contributions from each of these two large rivers remain uncertain knowledge of sediment sources to the tidal flat is critical for understanding the evolution of this muddy coast impacted by the large rivers the present study focuses on tracking the sediment source of the tidal flat deposits based on sediment magnetic properties and geochemical analyses as well as statistical analysis the study shows that sediments to the north of yangkougang site 9 have lower values of saturation isothermal remanence magnetization sirm magnetic susceptibility demagnetization parameter s 100 ratios lower fe al values and higher ca concentrations while the opposite is true for samples south to haozhigang site 18 in addition sirm values of the 63 m fractions generally display increasing trend from north to south these results suggest that sediment sources rather than particle size variation are the dominant factors influencing the bulk magnetic properties in light of the sediment composition comparison between the yellow river and yangtze river factor analysis is used to identify sediment source of the tidal flat sediments it is indicated that the yellow river in its former course is the dominant supplier for sites to the north of yangkougang site 9 while the yangtze river is the dominant supplier for sites to the south of haozhigang site 18 the coast between yangkougang site 9 and haozhigang site 18 is a transition zone influenced by both rivers the inferred provenance contrasts are consistent with the pattern of coastal geomorphological evolution our data also suggest that sediments eroded from the former yellow river delta have contributed to the evolution of the yangtze estuary in historical time this study demonstrates that a combined magnetic and geochemical fingerprinting techniques in couple with statistical analysis is valuable for identifying sediment sources of tidal flats and deltas influenced by large rivers in the world

paleoenvironmental implications from biomarker and stable isotope investigations on the pliocene velenje lignite seam slovenia a pliocene lignite seam up to 160 m thick occurs in the velenje basin slovenia the seam originated in a topogenous mire and evolved within a non marine transgressive setting differences in soluble organic matter yield and hydrocarbon content of borehole samples from the lignite are related to differences in the composition of free lipids of microbial origin and or hydrocarbons derived from the biogeochemical degradation of plant tissue variations of the redox conditions within the mire are reflected by pristane phytane ratios the abundance of terpenoid biomarkers indicates the predominance of gymnosperms over angiosperms which is consistent with palynomorphic spectra dominated by pollen of the sequoia taxodium metasequoia plant community rather than by angiosperms evidence is also provided that the content of land plant derived biomarkers and the preservation of plant tissue is controlled by the input of resin rich decay resistant conifers sections of the seam characterized by a high degree of gelification of humotelinite gelification index show high contents of hop 17 21 ene but low hopane concentrations the results suggest that the gelification of plant tissue may be governed by the activity of anaerobic rather than aerobic bacteria despite the minor variation in the proportions of gymnosperms versus angiosperms in the peat forming vegetation a general influence of the floral assemblage on carbon isotopic composition of the coals 13c 25 3 to 27 0 is proposed carbon cycling during biogeochemical decomposition of plant tissue by bacteria is assumed to affect the 13c value of the lignite petrographic and geochemical data of gelified and ungelified fossil wood provide evidence that gelification may be governed by microorganisms e g anaerobic bacteria different from those responsible for decreasing cellulose contents during early diagenetic aerobic degradation of wood based on the molecular composition of terpenoid biomarkers the wood fragments are identified as derived from gymnosperms the relative proportions of saturated versus aromatic hydrocarbon fractions of fossil gymnosperms display a general tendency towards lower values in gelified wood remains this indicates that bacteria involved in gelification of plant tissue may also be involved in aromatisation of diterpenoid hydrocarbons the chemotaxonomical classification of the macrofossils as gymnosperms is corroborated by the mean carbon isotopic compositions of the macrofossils 13c 24 5 and the extracted cellulose 13c 22 0 the higher isotopic difference of about 2 5 between cellulose and fossil wood compared to that found in modern trees can most probably be explained by the smaller effect of 13c discrimination for cellulose when compared with wood during decomposition chem geol 158 1999 121 compared with the coals the 13c values of wood and extracted cellulose are affected to a minor extent by microbial activity

paleoenvironment of the upper oligocene trbovlje coal seam slovenia abstract in the trbovlje region slovenia an upper oligocene coal seam up to 30 m thick developed in a topogenous mire and evolved within a transgressive setting the lower ash rich part of the seam unit i accumulated in a forest swamp strongly influenced by fluvial activity palynomorph spectra are dominated by taxodiaceae cupressaceae pollen ash yields decrease in the middle unit ii and upper part of the seam unit iii indicating decreasing fluvial activity an increase in cao contents reflects increasing amounts of inflowing water from an alkaline lake which progressively controlled peat hydrology in units ii and iii high sulfur contents in the nonmarine coal are a result of the carbonate rich water abundant pollen and spores from myricaceae and polypodiaceae indicate that unit ii represents a bush moor during deposition of unit iii this environment was replaced by a reed moor sapropelic coal unit iv and sapropelic shale unit v accumulated in a relatively large lake which was established by another water table rise the interpreted environmental changes are confirmed by biomarker data pristane phytane ratios reflect variations of the redox conditions within the mire and reach a minimum in the sapropelic unit iv the abundances of gymnosperm and angiosperm derived terpenoid hydrocarbons testify the predominance of gymnosperms over angiosperms during early peat stages unit i and increasing proportions of angiosperms during deposition of units ii and iii highest contents of diterpenoids coincide with maxima in the preservation of plant tissue tpi within unit i wet forest swamp suggesting that tpi is partly controlled by the input of resin rich decay resistant conifers sections of the seam characterized by advanced gelification show low steroids hopanoids ratios the results imply that gelification of plant tissue is related to increased microbial activity evidence is provided that the hopanes could be used as a measure for the activity of aerobic bacteria whereas for the hop 17 21 ene a microbial origin from anaerobic iron reducing bacteria is assumed a general influence of the floral assemblage and of varying contributions of algal biomass on carbon isotopic composition of the organic matter 13 c 24 0 to 28 1 is proposed carbon cycling during biogeochemical decomposition of plant tissue by bacteria is assumed to affect the 13 c values of the coal fossil wood collected from the seam is identified as derived from gymnosperms based on the molecular composition of terpenoid hydrocarbons this chemotaxonomical classification is corroborated by the mean carbon isotopic compositions of the fossil wood 13 c 24 0 and by the 13 c value 21 8 of the extracted cellulose from one macrofossil the low cellulose content of the sample 2 7 together with the slightly higher isotopic difference of 1 6 between cellulose and fossil wood compared to that found in modern trees can most probably be explained by the possible reversal in 13 c discrimination for cellulose when compared with wood in highly degraded samples

an organic geochemical perspective on terrestrialization the colonization of land required new strategies for safe gamete diaspore dispersal and to cope with desiccation harmful radiation fire and gravity accordingly the morphology behaviour and physiology of the organisms changed here we explore to what extent physiological adaptations reflected in the molecular content of the sediments add to our understanding of the terrestrialization many compounds considered characteristic of land organisms do not provide valuable information from the fossil record since 1 they were not preserved 2 they occur or correspond to substances that evolved prior to the terrestrialization e g cutan vs algaenan cellulose or 3 they have been changed diagenetically and or catagenetically the latter leads to geo macro molecules without a chemical fingerprint relating them to their original bio macro molecules despite sometimes excellent morphological preservation of the organic remains nevertheless some molecular markers and their stable isotopes provide independent information on the terrestrialization process the odd predominance of n alkane surface waxes is a feature already apparent in early land plants and could with caution be used as such furthermore fossil terpenoids and their derivatives are valuable for reconstructing the evolution of major plant groups the radiation of the phenylpropanoid pathway with for example sporopollenin and lignin seems to be closely related to the evolution of land plants as for other disciplines occupied with unravelling past life and environment organic geochemistry relies heavily on the paradigm that the present provides a key to the past for organic geochemistry the biosynthetic pathways of living organisms provide such a key the biosynthetic differences between organisms provide insight into the evolution of biosynthetic pathways and this can be applied to and calibrated against the fossil record evolution also implies adaptation and by linking species ecology to their biochemistry the adaptive value of the biosynthetic pathways and the biomolecules produced may be resolved this biosynthetic link to environment can also be applied to the past for instance the notion that oxygen is required in steroid and non hopanoid triterpenoid synthesis implies that analysis of steroids in ancient sediments may help to unravel the early evolution of the atmosphere summons et al 2006 analogous to the oxygenation of the earth s atmosphere terrestrialization also required major adaptations of the terrestrializing organisms to the living conditions on land the conquest of land required the development or strengthening of supportive structures such as skeletons stems and roots to withstand earth s gravity without the support of water and to resist wind it also demanded water saving strategies such as arthropod and plant cuticles vertebrate skin and cork to survive low humidity environments and sometimes fire as well as the development of water conducting tissues in plants roots tracheids finally the higher exposure to harmful radiation required sunscreens such as pigments aromatic and other substances as uv filters whereas the endoand exoskeletal adaptations are intrinsically based on the formation of large biopolymers water saving and uv protection may be also realized by means of smaller molecules our working hypothesis is that the major changes in biosynthetic pathways which accompanied the terrestrialization of organisms are reflected in the molecular composition of the organic matter present in palaeozoic sedimentary rocks for instance a minor change in the biosynthesis of sporopollenin may have led to lignin in return we can expect the changes in composition of the organic matter om in palaeozoic rocks to help determine following evolutionary trends the question being asked is to what extent is our working hypothesis valid and what does this provide us with to understand terrestrialization we restrict ourselves to primary producers and arthropods since they have a rich fossil record both organic geochemically and as microand macroscopic remains we exclude other terrestrial heterotrophic life forms worms snails vertebrates etc since they do not usually leave a chemically characteristic signature in the sediments from vecoli m clement g meyer berthaud b eds the terrestrialization process modelling complex interactions at the biosphere geosphere interface geological society london special publications 339 11 36 doi 10 1144 sp339 3 0305 8719 10 15 00 the geological society of london 2010 organic matter analysis lipids and

hydrogen isotope ratios of aliphatic and diterpenoid hydrocarbons in coals and carbonaceous mudstones from the liaohe basin china abstract hydrogen isotope compositions of the aliphatic and diterpenoid hydrocarbons were determined for five coal and carbonaceous mudstone samples collected from drilling cores 1531 1767 m depths in the liaohe basin china the bulk organic materials were mainly derived from terrestrial higher plants d values for most of the n alkanes varied from 150 to 220 and were not significantly different among the samples pristane was 34 69 depleted in d relative to phytane both pristane and phytane however had the same trend of variation in d from sample to sample diterpenoids were on average 49 81 depleted in d relative to the n alkanes variations in d also occurred between different diterpenoids indicating a different source for these compounds an enrichment process for the heavy hydrogen isotope was observed as expected when a compound was progressively altered through diagenesis especially the dehydrogenation process overall d and 13c showed distinct patterns between structurally different lipid classes although possible hydrogen exchange cannot be completely excluded during maturation our results further support the notion that hydrogen isotopes of lipid biomarkers from ancient sediments can be used to assess the origin of the organic matter to determine oil source rock correlation and perhaps to reconstruct the paleoenvironment under which the organic material was deposited

terpenoid composition and botanical affinity of cretaceous resins from india and myanmar abstract fossil resins from the cretaceous sediments of meghalaya india and kachin myanmar burma were analysed using curie point pyrolysis gas chromatography mass spectrometry and thermochemolysis gas chromatography mass spectrometry to help elucidate their botanical source the major pyrolysis products and methyl esterified thermochemolysis products of both the resins were abietane and labdane type diterpenoids with minor amount of sesquiterpenoids the thermochemolysis products also included methyl 16 17 dinor callitrisate methyl 16 17 dinor dehydroabietate and methyl 8 pimaren 18 oate the latter two from just the myanmarese resin the exclusive presence of both labdane and abietane diterpenoids and the lack of phenolic terpenoids may suggest that the studied cretaceous resins were derived from pinaceae pine family conifers

topographic mapping on large scale tidal flats with an iterative approach on the waterline method abstract tidal flats which are both a natural ecosystem and a type of landscape are of significant importance to ecosystem function and land resource potential morphologic monitoring of tidal flats has become increasingly important with respect to achieving sustainable development targets remote sensing is an established technique for the measurement of topography over tidal flats of the available methods the waterline method is particularly effective for constructing a digital elevation model dem of intertidal areas however application of the waterline method is more limited in large scale shifting tidal flats areas where the tides are not synchronized and the waterline is not a quasi contour line for this study a topographical map of the intertidal regions within the radial sand ridges rsr along the jiangsu coast china was generated using an iterative approach on the waterline method a series of 21 multi temporal satellite images 18 hj 1a b ccd and three landsat tm oli of the rsr area collected at different water levels within a five month period 31 december 2013 28 may 2014 was used to extract waterlines based on feature extraction techniques and artificial further modification these remotely sensed waterlines were combined with the corresponding water levels from the model waterlines simulated by a hydrodynamic model with an initial generalized dem of exposed tidal flats based on the 21 heighted remotely sensed waterlines a dem was constructed using the anudem interpolation method using this new dem as the input data it was re entered into the hydrodynamic model and a new round of water level assignment of waterlines was performed a third and final output dem was generated covering an area of approximately 1900 km2 of tidal flats in the rsr the water level simulation accuracy of the hydrodynamic model was within 0 15 m based on five real time tide stations and the height accuracy root mean square error of the final dem was 0 182 m based on six transects of measured data this study aimed at construction of an accurate dem for a large scale high variable zone within a short timespan based on an iterative way of the waterline method

stable carbon isotope ratios of aliphatic biomarkers in late palaeozoic coals abstract stable carbon isotope ratios for aliphatic biomarkers were measured on 34 late palaeozoic coals compound specific isotope analysis allowed the determination of 13c values of individual organic compounds such as chlorophyll side chain derived substances pristane and phytane leaf wax constituents n alkanes or bacteria related compounds hopanoids pristane and phytane can be regarded as excellent isotopic tracer molecules to ascertain isotope fractionation during primary production of organic matter by land plants in the late palaeozoic compared to the organic carbon isotope values for total terrestrial organic carbon partly different isotope shifts and temporal trends are discernible for these isoprenoids such differences in carbon isotope ratios of total terrestrial organic matter and isoprenoids indicate that both isotope data sets record different bio geochemical information since phytol derived isoprenoids are directly linked to the primary production of organic matter their carbon isotopic properties seem to be most appropriate for the reconstruction of ecological systems and climate in the palaeozoic interestingly isotopic values of isoprenoids and hopanoids were not significantly affected by maturity and maceral composition of the coals however differences between the isotopic composition of total organic matter and of phytane 13c values and differences between the isotopic composition of total organic matter and of hopane seem to correlate with provenance of the samples i e samples from different basins show different values hence variations in different types of organic biomass might be successfully traced by the isotopic properties of characteristic molecular fossils in palaeozoic coals this might become an appropriate approach for future palaeoenvironmental palaeoclimatic and palaeogeographical studies in conclusion the present study clearly demonstrates that molecular and carbon isotopic analyses of terrestrial organic matter range in resolution from bulk to compound specific analyses and it allows for the reconstruction of ecological and climatic conditions in the late palaeozoic

paleoclimate reconstruction from petrography and biomarker geochemistry from permian humic coals in sydney coal basin australia abstract the character of the coal in tomago and greta coal measures are similar to other coals from the sydney coal basin with variation from vitrinite rich to inertinite rich coal a type iii organic matter om linked to continental higher plants and a perhydrous type iii similar to type ii were found by rock eval analysis the coexistence of inertinite with algae botryococcus in the greta coals explains the high hi in the perhydrous type the gangamopteris flora that is reported in the greta coal measures grew after plants in a taiga like the recent birch forests in russia retallack 1980 the glossopteris flora that is reported in the tomago coal measures grew in a swamp forest based upon the botanic zonation this flora was located in the cold temperate biome that was located in gondwanaland except for antarctica which was in the glacial biome diterpane analysis results reveal alternation of wet and dry periods existed during the deposition of lewis coals in the greta coal measures during the kungurian and an increase of dryness is noted from upper donaldson to beresfield in the tomago coal measures during the capitanian based on analysis of aromatics and diterpanes the same periods of dryness and wetness alternate during the coal deposition in the sydney coal basin these climatic changes correspond to high frequency cycles n alkanes naphtalenes and phenanthrenes and does not alter the paleoenvironmental and paleoclimatic interpretation the comparison between biomarkers from coals and isotopes from marine birgenheier et al 2010 and terrestrial retallack et al 2011 deposits allow us to identify precise dry wet climate and glacial interglacial periods during the permian

chemical evolution of miocene wood example from the belchatow brown coal deposit central poland abstract miocene conifer wood samples from the belchatow brown coal deposit in poland were studied in order to discuss a range of chemical variations that occur as a result of biochemical coalification petrographic analysis ultimate analysis electron microprobe technique and ftir spectroscopy were used in this study our data show several progressive trends in functional groups distribution that take place during the wood transformation from group 1 to group 4 such as an overall increase in aromaticity an increase in lignin cellulose ratio and an increase in oxygen functionalities other observations include an increase in aliphatic stretching and bending functionalities from groups 1 to 3 followed by a decrease in the wood of group 4 appearance of aliphatic out of plane bands in group 3 and increase in group 4 an increase in ch2 ch3 in group 4 compared to the other groups and decrease in o h groups in group 4 compared to other groups these observations together with other chemical and petrological observations indicate that the progressive elimination of cellulose and modification of lignin are dominant processes of the wood transformation

sesqui and diterpenoid biomarkers preserved in taxodium rich oligocene oxbow lake clays weisselster basin germany several diterpenoids of the abietane pimarane and phyllocladane type and three cadalanetype sesquiterpenoids have been identified in the organic solvent extracts of lower oligocene clay sediments haselbach strata saxony germany the sediment contains needles and cone scales of a fossil taxodium species which represents the only conifer in the samples a clear correlation between the observed conifer biomarkers and taxodium is evident apart from diterpenoids detected previously in other sediments a new diaromatic totarane diterpenoid is reported in isolated fossil and recent taxodium needles and cone scales as well as in the haselbach clays a phenolic diterpenoid of the abietane type ferruginol has been identified the results indicate that the taxodium rich clay samples contain several diterpenoids which so far have been used as biomarkers for other conifer families and thus the chemotaxonomical use of diterpenoid biomarkers for the differentiation of fossil conifer families has to be revised

parameters determining the carbon isotopic composition of coal and fossil wood in the early miocene oberdorf lignite seam styrian basin austria abstract petrographical and geochemical data of gelified and ungelified fossil wood from the early miocene oberdorf lignite seam styrian basin austria provide evidence that the early diagenetic aerobic degradation of wood by fungi may be followed by further decomposition under reducing conditions by the activity of anaerobic bacteria based on the molecular compositions of terpenoid hydrocarbons the wood fragments in the lignite are identified as gymnosperms this result is corroborated by the mean isotopic composition 13c 24 2 of the macrofossils the isotopic difference between fossil wood and extracted cellulose of most samples 3 9 2 5 is higher than in modern trees which can be explained by the smaller effect of 13c discrimination during decomposition of cellulose when compared with wood the mean carbon isotope values found for gymnosperms and coals 24 2 and 24 7 respectively confirm the results from biomarker analyses indicating that the peat forming vegetation of the oberdorf seam was dominated by gymnosperm taxa minor variation in the relative contributions of gymnosperms and angiosperms to coal deposition is of negligible influence on the isotopic composition of the coals cross correlations between 13c of the coals soluble organic matter yield and the proportions of liptinite macerals of higher plant origin imply that the carbon isotopic composition may be affected by the contents of plant lipids because of their 13c values ranging from 5 to 10 less than whole plant tissue values an isotopic shift of the coals towards more negative values due to the activity of prokaryotes i e anaerobic bacteria in organic matter degradation is proposed the results obtained from the early miocene oberdorf lignite indicate that the carbon isotope ratios of the coals are primarily affected by varying contributions of different parts of whole plant tissue due to their different isotopic and molecular compositions e g epicuticular leaf waxes resins wood and their different decay resistance against the early diagenetic changes involved in organic matter decomposition carbon cycling during anoxic decomposition of plant derived organic matter is assumed to affect the 13c values of coal 13c values of wood and extracted cellulose are affected only to a minor extent

organic geochemical indicators of biological sulphate reduction in early diagenetic znpb mineralization the bois madame deposit gard france abstract at bois madame gard france zn pb s mineralization zn pb 4 occurs in dolomitized kimmeridgian carbonates very near layers which are rich in organic matter of planktonic origin previous geological and geochemical studies have suggested early syn or diagenetic ore deposition controlled by sulphate reducing bacteria the metals probably having originated from regionally mineralized triassic or liassic formations rock eval pyrolysis data complemented by biomarkers show that the organic matter reached only the organic diagenesis catagenesis transition owing to burial pb deposit as in many pb zn s deposits the hydrocarbons almost certainly autochthonous show no indication of relatively late alteration by biodegradation or water washing the presence of hopanes c 27 35 with high abundance in the c 27 32 range indicate that intense bacterial activity occurred during early diagenesis under su ic anoxic conditions this interpretation is reinforced by the presence of n alkanes in the range n c 22 to n c 28 dominated by compounds with an even number of carbon atoms which may have derived from the reduction of bacterial fatty acids except for these even number n alkanes the organic geochemical evidence for sulphate reducing bacteria during early diagenesis must remain equivocal

vascular plant biomarkers as proxies for palaeoflora and palaeoclimatic changes at the dogger malm transition of the paris basin france abstract vascular plant biomarkers are used here as a chemostratigraphic tool for tracing both palaeoflora and palaeoclimatic changes during the callovian and oxfordian in the paris basin the retene cadalene ratio shows low values in claystones from the middle callovian to the end of the lower oxfordian then increases drastically from the end of the lower oxfordian cordatum zone synchronously with the progressive development of the oxfordian carbonate platform the relative proportion of retene a conifer biomarker is strongly correlated with the abundance of some of its diagenetic precursors and with saturated diterpanes some of these are very common and abundant in the pinaceae family while specific markers for non pinaceae conifers are not detected thus the increase in the retene cadalene ratio around the cordatum zone reflects the rising proportion of pinaceae on the london brabant massif which was the nearest land from the locations studied as pinaceae show many morphological adaptations to dry climate compared to the other plants reported in the jurassic taphofloras of the paris basin their increasing proportion indicates an increasing aridity this climatic change is also supported by published geochemical palaeobiogeographical palynological palaeobotanical and mineralogical data a comparable increase in the relative proportion of retene was also described for the oxfordian of western australia which could be an argument for a worldwide increase in aridity at the end of the lower oxfordian

monocyclic alkanes in ordovician organic matter abstract the major compounds in the c 15 branched cyclic alkane fractions of two ordovician oils pine unit and midland farms oils and an immature ordovician rock guttenberg oil rock are monocyclics one series of these compounds was identified as n alkylcyclohexanes and another tentatively identified as methyl n alkylcyclohexanes the carbon number distribution of these compounds resembled those of the n alkanes found in these samples with an odd carbon number predominance it is suggested that the monocyclic alkanes in these ordovician samples may be principally derived from the cyclisation of straight chain algal fatty acids by mechanisms that involve decarboxylation however there is evidence from the m z 97 fragmentograms of these samples to indicate that methyl n alkylcyclohexanes can also be derived from fatty acids by a less preferred mechanism that does not involve decarboxylation or from other precursors in addition a sample of kerogen from the guttenberg oil rock was hydrously pyrolysed the saturated hydrocarbon products of this experiment showed very similar distributions including monocyclics to those observed in the ordovician oils this suggests that although the oils and the guttenberg oil rock come from widely differing geographical locations their precursor algal derived organic matter was very similar

vegetation differences and diagenetic changes between two bulgarian lignite deposits insights from coal petrology and biomarker composition abstract during the miocene numerous sedimentary basins formed on the territory of bulgaria as a result of the extensional tectonic settings related to the post orogenic development of the late alpine orogen in this study we review the petrographic composition and biomarker assemblage of two adjacent basins in western bulgaria i e beli breg and staniantsi basins both contain lignite formed during late miocene c 6 ma despite similar tectonic settings and depositional environments the lignite seams possess different petrographic and organic geochemical characteristics reflecting differences in the peat forming palaeo communities and facies variations the peat forming vegetation in beli breg basin was dominated by decay resistant coniferous plants as indicated by abundant fossil wood remains very good tissue preservation and a biomarker assemblage dominated by diterpenoids in contrast staniantsi lignite is poor in fossil wood and contains a significant amount of triterpenoid biomarkers suggesting the predominance of angiosperm plants in the swamp the results of the biomarker analyses are consistent with palaeobotanical and palynological data from the literature the lignite seams in both basins formed under frequently changing eh conditions as indicated by the severe degradation of the non gymnosperm tissues the low gelification index values and the variations in pristane phytane ratio probably as a result of seasonal drying of the swamps and changes of the ground water table hopanoid contents in beli breg lignite are very low and are consistent with the abundance of decay resistant vegetation in contrast bacterial activity was obviously higher in the staniantsi swamp however resulting only in slightly enhanced gelification of plant tissues the geochemical data suggest that the diagenetic changes of the organic matter were mainly governed by thermal degradation rather than bacterial activity