depositional environment and hydrocarbon source potential of the lower miocene oil shale deposit in the aleksinac basin serbia abstract the most prolific oil shale deposit in serbia is located in the aleksinac basin and is assigned to the lower miocene depositional environments and hydrocarbon potential were assessed for the aleksinac oil shale and coal layers through bulk geochemical organic petrographical biomarker and carbon isotope data from core samples from a single well maturity parameters vitrinite reflectance tmax biomarker isomerisation ratios prove that the organic matter om is immature a lower lacustrine oil shale sequence is comprised of alternating sandstone and clay rich rocks and some thin coal beds indicating strong variations in depositional environment this stratum is covered with thick sandstone 50 m terminated by the main 4 m thick coal seam that was deposited in a low lying mire as evidenced by high total sulfur and mineral matrix contents the plant input was dominated by angiosperms a relative rise in water level led to the drowning of the swamp and to the deposition of a 60 m thick upper oil shale in a lacustrine environment the om of the oil shale is dominated by kerogen type i lamalginite biomarker data suggest a stratified water column that likely formed due to differences in salinity the stratified water column led to a strictly anoxic environment and photic zone euxinia in a mesosalinar hydrologically closed lake which enabled the accumulation of uncommonly high amounts of organic material average toc 18 0 wt with excellent preservation average hi 743 mg hc g toc

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

uranium series ages of travertines and timing of the last glaciation in the northern yellowstone area wyoming montana uranium series age determinations by mass spectrometric methods were done for travertines and associated carbonate veins related to clastic deposits of the last glaciation pinedale in the northern yellowstone area dramatic variations in the hydrologic head are inferred from variations in the elevation of travertine deposition with time and are consistent with the expected hydrologic effects of glaciation we determine the following chronology of the pinedale glaciation with the key assumption that travertine deposits and associated carbonate veins perched high above present thermal springs were deposited when glaciers filled the valley below these perched deposits 1 the early pinedale outlet glacier advanced well downvalley between 47 000 and 34 000 yr b p 2 the outlet glacier receded to an interstadial position between 34 000 and 30 000 yr b p 3 an extensive pinedale ice advance occurred between 30 000 and 22 500 yr b p 4 a major recession occurred between 22 500 and 19 500 yr b p 5 a minor readvance deckard flats culminated after 19 500 yr b p and 6 recession from the deckard flats position was completed before 15 500 yr b p this chronology is consistent with the general trend of climatic changes in the northern hemisphere as revealed by recent high resolution ice core records from the greenland ice sheet

petrological and geochemical composition of lignite from the d field kolubara basin serbia abstract the upper miocene lignite from the main coal seam in the d field kolubara basin is a typical humic coal with huminite liptinite and inertinite concentrations of up to 83 7 vol 17 2 vol and 15 5 vol respectively in the huminite group textinite and ulminite are the most abundant macerals with variable amounts of densinite and attrinite liptodetrinite and sporinite are the most common macerals of the liptinite group while inertodetrinite is the most abundant maceral of the inertinite group the mineral matter consists mostly of clay minerals the main sources of organic matter were gymnosperms conifers and microbial biomass followed by angiosperms based on composition of saturated and aromatic diterpenoids it has been established that coal forming plants belonged to the gymnosperm families taxodiaceae podocarpaceae cupressaceae araucariaceae phyllocladaceae and pinaceae peatification occurred in neutral to slightly acidic fresh water environment composition and distribution of biomarkers show that diagenetic changes of the organic matter were mainly governed by bacterial activity in a suboxic to oxic environment based on distribution of aromatic diterpenoids a novel diagenetic pathway for transformation of abietane type precursors under suboxic to oxic conditions is proposed variations in compositions of macerals and biomarkers are in concordance with pronounced seasonality during pontian which caused changes in the water level redox conditions during peatification and to some extent vegetation differences in the paleo plant communities

late pleistocene glacial sequence in the area of the high plain of bogota eastern cordillera colombia abstract four main glacial events could be reconstructed on the basis of morphologic and 14c evidence in the parano regions surrounding the high plain of bogota eastern cordillera colombia in the area four distinct morainic levels were recognized between ca 2750 3000 m and ca 3750 m radiocarbon dates in combination with climatological data derived from palynological evidence indicate that morainic complex 4 was formed between ca 13 000 12 400 yr b p complex 3 between ca 18 000 14 000 yr b p complex 2 between ca 22 500 19 500 yr b p whereas complex 1 may be of middle last glacial age or of penultimate glacial age the spatial distribution of moraines throughout the area clearly shows that limits of former glacier systems were strongly influenced by local climatological conditions

petrographical and organic geochemical study of the kovin lignite deposit serbia abstract the origin of the organic matter om and the characteristics of the depositional environment of lignites from the upper miocene kovin deposit hosting three coal seams of serbia were evaluated based on petrographic data bulk organic geochemical parameters biomarker analysis and stable isotope geochemistry 13c of individual biomarkers samples were collected from four boreholes gd 601 and gd 603 the a field and kb 79 and kb 91 the b field representing different parts of coal seams i ii and iii investigated lignites are typical humic coals the om of lignites is derived from woody vegetation and herbaceous peat forming plants with prevalence of the former in most samples peat forming vegetation is characterized by abundant decay resistant gymnosperm coniferous plants followed by a low amount of angiosperms lignite forming plants mostly belonged to the gymnosperm families cupressaceae taxodiaceae phyllocladaceae and pinaceae slight input of ferns fungi and aquatic macrophyta to lignite om is also evident distributions of hopanoids and isotopic compositions of these biomarkers reflect the activity of various microbial populations represented by methanotrophic chemoautotrophic and heterotrophic bacteria during diagenesis prominent c28 28 30 bisnorneohop 13 18 ene was observed for the first time in the lignite extracts according to the 13c value it was probably derived from chemoautotrophic bacteria c28 28 30 bisnorneohop 13 18 ene could be one of the possible precursors of a series of orphan aromatic hopanoids bearing an ethyl group at c 21 via progressive aromatization peatification proceeded in a fresh water environment under variable redox conditions from anoxic to slightly oxic all three coal seams are heterogeneous the lower parts of the coal seams represent a topogenous fresh water peat mire with open water areas which was subjected to inundations the upper parts of coal seams represent a wet forest swamp with relatively stable conditions despite the observed variations in all three coal seams the mean values of petrographic and organic geochemical parameters suggest general increasing of wetness and establishment of more stable conditions from seam iii to seam i maceral and biomarker data indicate that rapid flooding of the bogs stopped peat growth in all three coal seams relatively frequent variations in all three coal seams followed by repetition of lignite characteristics depict well the pronounced seasonality e g short term cycles of the climate during late miocene in investigated area

paleoenvironmental settings of the sofia lignite basin insights from coal petrography and molecular indicators abstract compositions of balsha lignite sofia coal bearing basin bulgaria and carbonaceous shales are studied by petrological and geochemical proxies the macropetrographic characteristic of profiles is relatively constant the lignite is generally composed of dull matrix coal containing significant amounts of xylite fragments the typical microscopic constituents of the lignite are the ulminite and less frequently textinite lenses scattered within attrinitic groundmass the maceral composition of the organic matter in carbonaceous shales does not differ significantly from that of the lignite samples biomarker assemblages of the extractable portions are determined by gas chromatography mass spectrometry additional information for the compositions of residues after extractions is obtained by tmah thermally assisted hydrolysis methylation petrographic contents lipid assemblage and tmah thermally assisted hydrolysis methylation data imply that the original peat bog is formed in fresh water forest swamp preferably composed by gymnosperms polar diterpenoids argue for cupressaceae s l taxodiaceae as the most probable vegetation for one of the profiles appreciable angiosperm rich herbaceous type flora contribution is assumed polar oleanane triterepenoids and their aromatized derivatives argue for angiosperm input the relevance of a norfriedel 8 en 10 one friedelin ratio for groundwater level appraisal is discussed it admits long period of high water level in the paleomire high content of vanillyl structures and subordinated presence of syringyl units in products of tmah thermally assisted hydrolysis methylation are hint for gymnospermae input in the paleoswamp and angiospermae contribution to one of the profiles cinnamyl phenolic units indicating non woody angiosperm vegetation presence are registered as well flavonoids in products are considered as taxonomic markers of cupressaceae plants in the paleoswamp

mineralogy petrography and organic geochemistry of miocene coal seams in the kinik coalfield soma basin western turkey insights into depositional environment and palaeovegetation abstract the kinik coalfield is located in the south westernmost part of the soma basin in western turkey and hosts all three miocene coal seams from bottom to top km2 km3 and kp1 this study presents the coal petrographical mineralogical and organic geochemical features of samples collected from two deep cores samples from seam km2 generally display low ash yields and high toc content whereas the km3 and kp1 seams are characterized by relatively high ash yields and low toc values furthermore total s content of the kp1 is very high up to 7 0 on dry basis the maceral composition the coal facies diagrams and the distributions of n alkanes and diterpenoids indicate changes of depositional conditions and vegetation in the palaeomires of the km2 seam during early miocene the precursor peat of km2 seam started accumulating under limnotelmatic conditions followed by pure telmatic ones consequently initial mixed vegetation was replaced by a conifer dominant assemblage in the palaeomires in the upper parts of the km2 seam the coal facies indices and high concentrations of n alkanes along with the relatively low di di tri terpenoid ratios are indicators of the higher contribution of herbaceous species and minor abundance of conifers in the palaeomires of km3 and kp1 seams nevertheless the mineralogical composition of the km3 and kp1 seams indicate increased clastic input and alkalinity in the palaeomires that could reduce preservation of organic matter thus high ash yields and low toc were obtained from these seams in addition sulphate rich water supply along with synchronous pyroclastic air borne input into the palaeomires caused elevated total s content of the kp1 seam

occurrence and palaeoenvironmental significance of aromatic hydrocarbon biomarkers in oligocene sediments from the mallik 5l 38 gas hydrate production research well canada abstract the aromatic hydrocarbon biomarker distributions of thirty oligocene sediment samples with different lithology lignite clay and sand from the japex jnoc gsc et al mallik 5l 38 gas hydrate production research well canada were analyzed using gas chromatography mass spectrometry gc ms the compositions vary with lithology indicating a change in palaeoenvironmental conditions at the time of deposition aromatic diterpenoids of the abietane type are more abundant in the lignite samples than in the clay samples and represent a gymnosperm e g conifer dominated palaeovegetation in contrast in the clay samples aromatic triterpenoids are generally preserved as major constituents indicating angiosperm dominated vegetation the sand samples contain only minor amounts of aromatic terpenoids but show a preference for diterpenoid gymnosperm markers to recognise gymnosperm versus angiosperm dominated palaeoenvironments a new ratio termed the angiosperm gymnosperm aromatic ratio agar has been developed thus the terpenoid distribution in the deltaic sediments provides information on the compositional changes in the plant community at the mallik site lignites and the hinterland clays over time concomitantly the changing dominance in the plant communities allows an insight into varying climatic conditions during the late oligocene in the area additionally the aromatic biomarker composition has been used to assess the level of thermal maturity of the organic matter in the mallik samples and indicates a prevailing immature character

geochemical appraisal of palaeovegetation and climate oscillation in the late miocene of western bulgaria abstract palaeobotanical methods and geochemical techniques were used to assess plant contribution and palaeoenvironment for the staniantsi basin bulgaria the aim was to connect palaeovegetation change and climate oscillation based on pollen and statistical analysis with organic geochemical proxies for a late miocene lacustrine to paludial sedimentary succession three samples from lignite marl cycles were studied the biomarker assemblage and bulk chemical data indicated that gymnosperms were not important in the palaeomire the presence of des a triterpenoids 17 21 seco triterpenoids hopanes a high content of a d ring monoaromatic hopane and aromatized triterpenoids suggested that photochemical and microbial processes significantly contributed to the alteration of the organic matter om a prolonged period of high water table and severe mechanical destruction promoted microbial activity prior to burial and enhanced decay a geochemical appraisal of short term climate oscillation ca 21 7 kyr was attempted within the limitations of the small number of samples studied the cycles are expressed as lignite marl clay layers combined with cyclic changes in swamp vegetation related to cyclic changes in groundwater level and inundation of the basin in periods of low water level swamp phase lignite accumulation took place preliminary results for selected samples suggest that the oscillation may be reflected in the content of friedelin vs possible degradation products the ratio of a chromatographic peak tentatively assigned as a norfriedel 8 en 10 one to friedelin is proposed as a means of detecting short term environmental cycles where values 1 reflect periods of inundation however time series analysis using densely sampled lignite clay layer oscillations are needed to confirm the value of this biomarker ratio for environmental reconstruction

on the fundamental difference between coal rank and coal type abstract this article addresses the fundamental difference between coal rank and coal type while theoretically settled long ago as being different aspects of coal systems science the two concepts are still often confounded in recent years this has resulted in the publication of several works stating that coal type changes with coal rank coal type refers solely to coals depositional origin and the maceral mineral admixture resulting from that origin coal types typically fall in to two categories humic coals developed from peat and sapropelic coals developed from organic mud either type may be allocthonous or autochthonous and within types further refinement of depositional environment can be made coal rank refers to the changes in geochemistry and resultant changes in reflectance caused by increasing thermal maturity of the coal thus it provides an overprint of maturity on existing coal types with proper techniques such as use of crossed polars and etching maceral forms can be differentiated even at high ranks and the original coal type determined

biomarker and micropetrographic investigations of coal from the krepoljin brown coal basin serbia abstract we investigated early diagenetic processes of the extractable organic matter from the miocene freshwater sequence which consists of coal fragments in clays sandstones and shales alternating with continuous brown coal layers we examined eight coals thirteen sediments and three non coaly underground layers the molecular assemblages of the identified aliphatic hydrocarbons in the krepoljin basin reflect the abundance of plant taxa as precursors or participants in the early diagenetic stage the data provide insight into the conditions prevailing in the lakes and bogs during early diagenesis the dominance of diterpanes indicates that the prevalent of the organic matter was of gymnosperous origin the hopanoid contents are considered to reflect microbial activity that the organic matter in the miocene krepoljin coal basin is immature was confirmed by the presence of biolipids such as hopanes c 27 17 h trisnorhopan saturated and aromatized abietanes pimaranes and phyllocladanes the most abundant compounds in all samples indicate a predominantly higher plant input related to the coniferous group but identification of the individual plant families was not possible amyrin and other triterpenoid derived triaromatic and triaromatic c ring cleaved hydrocarbons with triterpenoid structures are thought to be characteristic for angiosperms unsaturated compounds 2 triterpanes early intermediaries in the diagenetic transformation of angiosperms also indicate a low degree of sediment maturity

paleogeography and paleoecology of the upper miocene zillingdorf lignite deposit austria abstract the zillingdorf deposit formed during the late miocene filling of lake pannon and contains austria s largest lignite reserves two lignite seams are present and developed within frequently flooded low lying mires in near shore environments high sulphur contents are due to the influence of the brackish water body of lake pannon during peat accumulation a transgression forced the nw se trending shoreline northeastwards differences in soluble organic matter som yield and hydrocarbon content of borehole samples and woody macrofossils are related to differences in the content and composition of free lipids of microbial origin and or hydrocarbons derived from the biogeochemical degradation of plant tissue variations of pristane phytane ratios are interpreted to reflect differences in the redox conditions of the mire peatification in an acidic and aerobic environment is further reflected by the predominance of aromatic over saturated hydrocarbons the presence of an intense complex mixture in the gc traces due to biodegradation processes high ratios for diasterenes relative to sterenes and high concentration ratios of hopanes to hop 17 21 ene of the respective samples gelification of plant tissue is governed by microbial activity as indicated by the positive relationship between gelification index and hopanoids concentration the composition of terpenoid biomarkers indicates the predominance of gymnosperms over angiosperms and increasing proportions of angiosperms in the peat forming vegetation with decreasing depth in the upper seam from the sesqui and diterpenoids present in the lignite and fossil wood remnants a predominant role of species of the coniferales families cupressaceae taxodiaceae are concluded the preservation of plant tissue is governed by the presence absence of decay resistant gymnosperms a general influence of the floral assemblage on the isotopic composition of organic carbon of the lignite 13c 27 2 to 24 6 is proposed decomposition of plant tissue and biogeochemical carbon cycling is assumed to further affect the 13c values of the lignite carbon isotope data of fossil wood remnants are consistent with their chemotaxonomical classification as gymnosperms 13c between 22 5 and 24 9 and angiosperms 13c between 25 5 and 26 6 respectively the 13c data of the extracted cellulose reveal clear differences between fossil wood from gymnosperms average 13c 20 3 and angiosperms mean 13c 22 9 the higher isotopic difference of about 3 5 between cellulose and fossil wood compared to that found in modern trees is explained by the smaller effect of 13c discrimination for cellulose when compared with wood during decomposition

glacier fluctuations in the eastern andes of colombia south america during the last 45 000 radiocarbon years abstract major glacial advances in the eastern cordillera of colombia preceded the global ice volume maximum at ca 20 ka bp two glacial events are recognized for isotope stage 3 dated between probably 43 and 38 ka bp and between 36 and 31 ka bp the events are recorded in glacial deposits and strongly subdued morainic ramparts three glacial advances during isotope stage 2 are dated between 23 5 and 19 5 ka bp 18 0 and 15 5 ka bp and 13 5 and 12 5 ka bp the glacial landforms associated with the period 18 0 to 15 5 ka bp are most distinct the arcuate multiple morainic ridge system of up to tens of meters of height can be traced throughout the region the moraines that formed during the earlier isotope stage 2 advance are more subdued the youngest isotope stage 2 morainic complex consists of low winding ridges isotope stage 1 glaciations affected only the highest areas of the eastern cordillera where morainic complexes associated with at least three glacial events occur but remain poorly dated the glacial record of the colombian eastern cordillera registers high climatic variability in the tropical andes during the late quaternary period

biomarkers aromatic hydrocarbons and polar compounds in the neogene lignites and gangue sediments of the konin and turoszow brown coal basins poland abstract this paper presents geochemical characteristics of 35 samples of miocene lignites and gangue sediments clays sampled in the konin and turoszow brown coal basins poland lignites belonged to xylitic detro xylitic detritic and fusitic lithotypes organic geochemistry of them were investigated using such methods as rock eval pyrolysis gas chromatography mass spectrometry of separated aliphatic hydrocarbons compounds of medium polarity and methyl esters of fatty acids flash pyrolysis gc ms was applied for investigation of macromolecular organic matter of the samples reflected light microscopy was used to find maceral composition and huminite reflectance all samples organic matter show immature features well corresponding to its values of huminite reflectance 0 17 0 35 rock eval t max values were exceptionally low in all cases on average 387 c and they show high differentiation according to the lignite lithotypes with lowest values for xylites also other geochemical features of organic matter are lithotype dependant such as n alkanes and fatty acids distributions many biomarkers presence and distribution types and chemical composition of lignite macromolecular fraction it was possible to asses dominating sources of organic matter using relative concentrations of three groups of compounds with diterpene hopane and oleanane molecular structures most of miocene detritic lignites come from monocotyledonic material with some of them containing coniferal detritus like needle leaves xylitic lignites come from podocarpaceae pinaceae cupressaceae and taxodiaceae families what is indicated by diterpenoids and sesquitenoids distribution detro xylitic lignites show intermediate geochemical features between detritic and xylitic lignites

terpenoids in extracts of lower cretaceous ambers from the basque cantabrian basin el soplao cantabria spain paleochemotaxonomic aspects the composition of terpenoids from well preserved cretaceous fossil resins and plant tissues from the amber bearing deposits of el soplao and reocin in cantabria northern spain have been analyzed using gas chromatography mass spectrometry and the results are discussed using the terpenoid composition of extant conifers as a reference amber is present at many horizons within two units of coastal to shallow marine siliciclastics of albian and cenomanian age the fossil resins are associated with black amber jet and abundant well preserved plant cuticle compressions especially those of the extinct conifer genus frenelopsis cheirolepidiaceae we report the molecular characterization of two types of amber with different botanical origins one of them is characterized by the significant presence of phenolic terpenoids ferruginol totarol and hinokiol and pimaric isopimaric acids as well as their diagenetic products the presence of phenolic diterpenoids together with the lack of abietic and dehydroabietic acids excludes both pinaceae and araucariaceae as sources for this type of amber the biological diterpenoid composition is similar to that observed for extant cupressaceae the second type of amber is characterized by the absence of phenolic terpenoids and other specific biomarkers some terpenoids with uncertain structure were detected as well as the azulene derivative guaiazulene our results suggest that the amber from cantabria could be fossilized resin from frenelopsis and other undetermined botanical sources the biological terpenoid assemblage confirms a chemosystematic relationship between frenelopsis and modern cupressaceae

relationships between coal quality and organic geochemical parameters a case study of the hafik coal deposits sivas basin turkey abstract this study provides coal quality organic petrographic and organic geochemical data on tertiary subbituminous coal of the hafik area northwestern part of the sivas basin turkey coal petrological studies along with proximate and ultimate analyses were undertaken to determine the organic petrographic characteristics of the hafik coals huminite reflectances were found to be between 0 38 and 0 48 corresponding to an organic material rich and coal layers values characteristic of low maturity this parameter shows a good correlation with calorific values average 21 060 kj kg and average t max 422 c mineral matter diagenesis indicating immaturity the studied coals and organic material underwent only low grade transformation a consequence of low lithostatic pressure therefore the hafik coals are actually subbituminous in rank rock eval analysis results show types ii iii and iii kerogens the organic fraction of the coals is mostly comprised of humic group macerals gelinites with small percentages derived from the inertinite and liptinite groups in this study organic petrographic organic geochemical and coal quality data were compared the hafik deposit is a high ash high sulfur coal the mineral matter of the coals is comprised mainly of calcite and clay minerals

an unprecedented condensation pathway leading to the formation of phenolic c40 bis diterpenoids in sediments from the lower oligocene of the rhine rift valley abstract in the course of a detailed palaeoenvironmental study based on biomarker distributions in sediments of rupelian age lower oligocene from the rhine rift valley an outcrop sample rich in higher plant fossil remains was collected from a quarry near the city of burnhaupt le haut south alsace france in agreement with the macrofossil assemblage most of the biomarkers were related to terrigenous organic matter as evidenced by the presence of di and triterpenoid derivatives from vascular plants the aromatic hydrocarbon fraction was also shown to contain two predominant series of unknown c 40 oxygenated compounds as indicated by high resolution mass spectrometry isolation of the predominant compound from the first series and of two isomers from the second was undertaken to determine the structures from nuclear magnetic resonance nmr studies thus we determined that both series of compounds consist of bis diterpenoids made up of phenolic sub units related to totarol and sempervirol possibly originating from podocarpaceae their formation comprises a first step involving oxidative coupling between the two phenolic monomeric sub units via a free radical mechanism and leading to the formation of an ether bond first series of compounds or a carbon carbon bond second series of compounds in the case of the compounds from the second series a second acid catalysed cyclisation step likely results in the formation of a central dibenzofuranyl moiety it remains unclear however whether these condensation cyclization mechanisms are biologically mediated or result from diagenetic reactions

facies evolution and stratigraphic correlation in the early oligocene tard clay of hungary as revealed by maceral biomarker and stable isotope composition abstract hydrocarbon source rocks i e tard clay formation containing type ii organic matter were deposited in the hungarian paleogene basin during lower oligocene a major contribution of aquatic organisms green algae dinoflagellates chrysophyte algae and minor inputs from macrophytes and land plants to organic matter accumulation is indicated by n alkane distribution patterns composition of steroids and 13c of hydrocarbon biomarkers microbial communities included heterotrophic bacteria cyanobacteria chemoautotrophic bacteria as well as green sulphur bacteria the presence of methanotrophic bacteria is indicated by 13c depleted hop 17 21 ene higher inputs of terrestrial organic matter occurred during deposition of the lower and uppermost units of the tard clay formation the terpenoid hydrocarbon composition argues for angiosperm dominated vegetation in the area of the hungarian paleogene basin diterpenoid hydrocarbons derived from the resins of conifers are about 2 3 enriched in 13c compared to the angiosperm biomarkers environmental conditions changed from marine to brackish accompanied by oxygen depletion in the lower parts of the water column organic carbon accumulation during this period was a consequence of stagnant bottom water conditions in the hungarian paleogene basin due to salinity stratification this is indicated by low pristane phytane ratios varying from 0 27 to 1 44 enhanced ratios of dimethylated versus trimethylated mttcs 0 14 0 59 and the presence of aryl isoprenoids from 0 4 to 14 1 g g toc a major marine incursion is evidenced by stable isotope ratios of organic matter and carbonates in the uppermost member of the tard clay a transition from brackish towards normal marine conditions is proposed up to 3 anoxic cycles are recognized in the drill core sections separated by minima in pristane phytane ratios and maxima in the depth trends of di tri methylated mttcs and aryl isoprenoid concentrations in combination with the position of maxima of 13c of carbonate and organic matter and an abrupt decrease in perylene concentrations the cycles can be used for intra formational correlation of the tard clay

evaluation of paleoenvironment using terpenoid biomarkers in lignites and plant fossil from the miocene tokiguchi porcelain clay formation at the onada mine tajimi central japan abstract we investigated terpenoid biomarkers in muds from lignite seams clays from porcelain clay beds that slightly contain lignite and from a conifer cone macrofossil from the miocene tokiguchi porcelain clay formation of the tokai group in central japan as well as extant cones the n alkanes n alkanols suberin origin diterpenoids conifer origin hopanoids bacteria origin and steroids were mainly present in the lignite containing muds and clays on the other hand the diterpenoids triterpenoids angiosperm origin hopanoids and steroids were detected as major component in the conifer cone macrofossil in addition the diterpenoids were mainly detected in the extant conifer cones the low hopane isomer ratios and the detection of biosterols are confirmed to be immature in the lignite sediment and macrofossil in the formation the stanol sterol ratio values of the lignite containing muds and clays are much higher than that of the macrofossil the higher ratios in lignite containing muds and clays are possibly attributed to enhanced microbial reduction of organic matter under reduced condition in the swampy environments a large amount of angiosperm derived triterpenoids detected in the conifer cone macrofossil are considered as contaminants in the sample from sedimentary organic particles originated from detrital waxes of angiosperms such contamination might occur by migration of organic compounds within sediment after deposition the angiosperm derived polar terpenoids may be hardly affected by contamination by migration of organic matter from the adjacent sediments because these are less abundant in the conifer macrofossil thus it is suggested that the polar terpenoid biomarkers are more reliable as paleochemotaxonomic and paleovegetation indicators

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

the 14c dates and 13c 12c ratios of soil organic matter as a means of studying the past vegetation in intertropical regions examples from colombia south america abstract the 14 c ages and 13 c 12 c values were obtained on soil organic matter of various soils sampled in the guasca valley adjacent to the high plain of the sabana de bogota in the colombian cordillera oriental a soil distribution is observed as a function of climatic and altitudinal changes in the lowest parts of the valley planosols are found from the bottom of the valley to 2700 2800 m at altitudes up to 2900 m brunizems and ferrisols occur above 3000 m andic soils are almost everywhere present in more humid mountain zones at present the landscape is widely open without any natural forest nevertheless it was proved by pollen analytical data that at altitudes up to 3000 m the andean forest replaced a paramo formation 13 000 yr ago to conciliate the facts with the known evolution of the vegetal population a first hypothesis consists of admitting that open landscapes were due to a recent anthropogenic destruction of the forest the forest degradation hypothesis was tested by determination of the 13 c 12 c ratio because the trees have a 13 c of 25 to 28 influence of plants with c 3 photosynthesis pathway whereas herbs characteristic of open vegetation such as tropical grasses may have a 13 c of 23 to 16 due to a c 4 photosynthetic cycle the organic matter dated at 13 000 30 000 yr has 13 c close to 25 in the andic soil zone this indicates that at elevations of around 3000 m a cold paramo vegetation was probable for organic matter dated at 12 000 6000 yr 13 c shows a variation from 23 to 21 that does not indicate forest conditions it is uncertain that a forest stage occurred in the past for the planosols brunizem and ferrisol organic matter dated at 13 000 20 000 yr has a 13 c 23 compatible with the paramo vegetational phase occurring at that time for organic matter dated at 9500 yr and less 13 c varies from 20 to 17 these values do not confirm the evidence of forest conditions but rather the existence of open vegetation typified by a mixture of c 3 plants shrubs and rare trees and tropical graminaea thus the 13 c values prove that the valley has known drier and warmer influences that prevented the forest from developing during the holocene to explain the origin of the open landscapes of the valley the hypothesis of recent human deforestation must be discarded moreover the valley appears as a persistent dry enclave in the oriental cordillera

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

polar aromatic biomarkers in the miocene maritza east lignite bulgaria aromatic and polar compounds of lignite lithotype bitumens maritza east were analyzed diterpenoid phenols and ketophenols i e mainly ferruginol sugiol hinokione and products of their diagenetic transformations were identified as the dominant biomarkers a variety of sesquiterpenoids was present as well these compounds provided evidence for the assumption that members of the cupressaceae s 1 are the coal precursors polar triterpenoids i e lupeol lupenone adiantone and hopanones were present in subordinate quantities in the humoclarain sample these biomarkers support an input of deciduous angiosperm vegetation to the peat swamp source matter three diagenetic transformation schemes for the diterpenoid phenols ketophenols are proposed 1 ferruginol and or sugiol alteration through dehydrogenation demethylation and ring b cleavage 2 hinokione aromatization to simonellite and 3 7 ketototarol change through 7 ketototar 5 enol to 20 nor 3 oxo totara 5 10 6 dienol the identified diterpenoids demonstrated the presence of gymnospermae in the coal forming community furthermore the phenolic diterpenoids indicated a specific input of organic matter from conifers of the cupressaceae taxodiaceae or podocarpaceae as the most abundant trees in the coal forming swamp

paleoenvironmental conditions source and maturation of neogene organic matter from the siliciclastic deposits of the orava nowy targ basin abstract the orava nowy targ basin ontb is an intramontane depression filled with neogene and quaternary deposits located at the junction of the inner and outer carpathians the neogene infill of the basin consists mainly of siliciclastic rocks with very common lignite intercalations and is mostly of fluvial or lake origin the organic matter molecular analysis of seventeen neogene samples confirmed the terrigenous origin of organic matter with a predominance of higher plant input in most samples based on the distribution of n alkanes and steranes as well as the presence of tri and tetracyclic diterpenoids and triterpenoids representing oleanane ursane lupane chrysene and picene derivatives high concentrations of compounds originating from both angiosperms and gymnosperms suggest the presence of mixed forests additionally important input of mosses into the primary organic matter is indicated by the high concentration of n c 23 and presence of hop 17 21 enes in most samples a high average aromatic ring and conifer wood degradation index 0 7 indicate high activity of bacteria and wood degrading fungi in the sedimentary environment there was no evidence of weathering and scarce signs of biodegradation were identified all samples were subjected to water washing huminite reflectance and biomarker based parameters as well as the presence of unsaturated pentacyclic triterpenoids and steroids indicate an immature organic matter a trend of decreasing maturation of sediments from east to the west was observed as was a similarity of thermal maturity between the podhale synclinorium and the ontb although the latter seems to be coincidental a thermal gradient value of 35 c km was assumed for calculating the maximum thickness of eroded strata resulting in 1 1 6 km for the se area and a maximum temperature of the deepest buried samples equal to 45 65 c

perylene as an indicator of conifer fossil wood degradation by wood degrading fungi the occurrence of perylene in middle jurassic fossil wood and miocene xylites from poland is described along with its correlation with unsubstituted polycyclic aromatic hydrocarbons pahs as well as cellulose content both middle jurassic and miocene wood remnants were of relatively low maturity ca 0 2 0 3 vitrinite reflectance rr had excellent preservation of biomarkers and biomolecules and in the case of the middle jurassic fossil wood samples generally good preservation of anatomical structures due to early diagenetic mineralisation the results from 42 middle jurassic and 8 miocene most taxonomically defined fossil wood fragments demonstrated a negative correlation between the concentration of perylene and those of generally typical conifer biomarkers e g cadalene dehydroabietane simonellite and retene in addition good correlation r2 0 81 was observed between the ratio of perylene to the above conifer biomarkers and the ratio of pahs phenanthrene and fluoranthene and pyrene to the conifer biomarkers this implies that the high concentration of perylene in fossil wood indicate its extensive degradation during decay transport and early diagenesis we defined a conifer wood degradation index as cwdi perylene perylene cadalene retene simonellite dehydroabietane cwdi perylene perylene cadalene retene simonellite dehydroabietane and observed a wide range of values 0 001 for less degraded wood to 0 95 for highly degraded samples anatomical wood preservation was associated with cwdi values in most of the samples characterised by poorly preserved anatomy high cwdi values were observed while anatomically well preserved samples generally had lower cwdi values we determined similar 13c values for perylene from the fossil wood samples 26 4 to 27 8 whereas the values for the conifer biomarkers were slightly higher and varied from 25 6 to 26 6 in contrast pyrene was depleted in 13c 27 5 to 28 2 the carbon isotope values of perylene are consistent with an origin from wood degrading fungi

the role of ocean atmosphere reorganizations in glacial cycles abstract a case is made that glacial to interglacial transitions involve major reorganizations of the ocean atmosphere system such reorganizations constitute jumps between stable modes of operation which cause changes in the greenhouse gas content and albedo of the atmosphere only in this way can the rapidity of glacial terminations the hemispheric synchroneity and symmetry of mountain glaciation and the large polar air temperature and dustiness variations be accounted for if these reorganizations are driven in some fashion by orbitally induced seasonal insolation changes then the connection between insolation and climate is most likely through impacts of fresh water transport on the ocean s salinity distribution

irregular glacial interstadials recorded in a new greenland ice core the greenland ice sheet offers the most favourable conditions in the northern hemisphere for obtaining high resolution continuous time series of climate related parameters profiles of 18o 16o ratio along three previous deep greenland ice cores1 3 seemed to reveal irregular but well defined episodes of relatively mild climate conditions interstadials during the mid and late parts of the last glaciation but there has been some doubt as to whether the shifts in oxygen isotope ratio were genuine representations of changes in climate rather than artefacts due to disturbed stratification here we present results from a new deep ice core drilled at the summit of the greenland ice sheet where the depositional environ ment and the flow pattern of the ice are close to ideal for core recovery and analysis the results reproduce the previous findings to such a degree that the existence of the interstadial episodes can no longer be in doubt according to a preliminary timescale based on stratigraphic studies the interstadials lasted from 500 to 2 000 years and their irregular occurrence suggests complexity in the behaviour of the north atlantic ocean circulation

hazard consistent ground motions generation on the basis of uniform hazard fourier spectra design seismic forces depend on peak ground acceleration pga values and on the shape of response spectra rs dictated by building codes or that need to be evaluated on a site specific basis the pga values and rs strictly depend on earthquake magnitude and distance style of faulting and in cases near source effects e g rupture directivity as well as on the regional and local geological conditions at present there is no doubt that it is necessary to construct so called site and region specific building code provisions reflecting the influence of different magnitude events at different distances that may occur during the lifetime of the construction as well as the variety of local ground conditions a scheme of uniform hazard response spectra and pga estimation considering local site response is described in this article the assessments of these design parameters are obtained on the basis of uniform hazard fourier spectra using the concept of dominant earthquakes the effect of local geology is included by means of the soil reference site spectral ratios the results of using the method are presented for the regions characterized by different seismicity and tectonics and compared with the data obtained during the recent strong earthquakes the caucasus armenia the 1988 spitak earthquake region and the turan plate central asia the 1979 and 1984 gazli earthquakes region

quaternary glaciations in the rio mendoza valley argentine andes in the rio mendoza valley five pleistocene drifts and one holocene drift are distinguished by multiple relative age criteria including surface rock weathering development of rock varnish moraine morphology soil profile development and stratigraphic relationships several absolute ages suggest a preliminary chronology during the oldest uspallata glaciation a system of valley glaciers flowed 110 km from the andean drainage divide and 80 km from cerro aconcagua to terminate at 1850 m drift of this ice advance is older than a widespread tephra dated by fission track at 360 000 36 000 yr during the punta de vacas advance ice terminated at 2350 m while during the subsequent penitentes advance the glacier system ended at 2500 m a travertine layer overlying penitentes drift has u series age of 24 200 2000 yr b p the distribution of horcones drift which is inferred to represent the last glacial maximum delimits an independent ice stream that flowed 22 km down horcones valley to 2750 m a later readvance almacenes reached 3250 m confluencia drift is considered to be neoglacial in age and extends downvalley to 3300 m the moraine sequence is compared with those studied by caviedes 1972 along rio aconcagua on the chilean flank of the andes

relations of petrographical and geochemical parameters in the middle miocene lavanttal lignite austria abstract samples from two lignite seams lower seam upper seam of the lavanttal basin austria and additional xylite were investigated for variations in maceral composition petrography based facies indicators bulk geochemical parameters and molecular composition of hydrocarbons both seams originated in a topogenous mire and evolved within a transgressive setting the final drowning of the mire is indicated by sapropelic shales whereas the sapropelic shale overlying the lower seam was deposited in a freshwater lake the sapropelic shale above the upper seam represents a brackish lake numerous relationships are found between petrography based facies indicators and the geochemical composition of organic matter the contents of macerals of the liptinite group are positively correlated with soluble organic matter som yields and hydrogen index hi consistent with maceral composition and high hi values enhanced proportions of short chain n alkanes which are predominantly found in algae and microorganisms are obtained from samples of the sapropelic shales the final drowning of the mire is reflected by decreasing pristane phytane ratios due to the rise in ground water table and the establishment of anaerobic conditions as well as by decreasing ratios of diasterenes sterenes indicating increasing ph values in the mire the degree of gelification of plant tissue gelification index is governed by the microbial activity in the mire as indicated by the hopanes concentration the differences in floral assemblage during the formation of the lavanttal lignite seams are reflected by major differences in tissue preservation preservation of plant tissue tpi in the lavanttal lignite is obviously controlled by the presence absence of decay resistant gymnosperms in the peat forming vegetation and additionally influenced by the relative contribution of wood to coal formation the results provide evidence that valuable information for coal facies characterization could be obtained by petrography based and geochemical facies indicators an influence of the floral assemblage gymnosperms angiosperms ratio and of the contribution of algal biomass on carbon isotopic composition of the organic matter 13c 24 2 to 28 6 is proposed carbon cycling during biogeochemical decomposition of plant tissue by bacteria is suggested to affect the 13c values of the coal the chemotaxonomical classification of the xylites as gymnosperm remnants based on the molecular composition of terpenoid biomarkers is corroborated by the carbon isotopic composition of the xylites mean 13c 24 1 and the extracted cellulose mean 13c 20 2 the higher isotopic difference of about 3 9 between cellulose and total organic carbon of the xylites compared to the difference between cellulose and wood found in modern trees is explained by the smaller effect of decomposition on 13c of cellulose

comparative study of serbian miocene coals insights from biomarker composition abstract the origin of the organic matter om and the characteristics of the paleoenvironment of serbian brown coals covering a time span from the lower to the upper miocene were evaluated and compared based on comprehensive petrological and biomarker analyses investigated coals are typical humic coals peat forming vegetation is characterized by abundant decay resistant gymnosperm coniferous plants followed by variable amount of angiosperms coal forming plants belonged to the gymnosperm families taxodiaceae podocarpaceae cupressaceae araucariaceae phyllocladaceae and pinaceae peatification proceeded in fresh water environment under variable eh settings from anoxic to slightly oxic condition upper miocene lignites were formed in neutral to slightly acidic environment whereas lower and middle miocene coals were deposited under neutral to slightly alkaline and more reductive conditions which is the result of calcium rich surface waters derived from the surrounding jurassic to cretaceous calcareous country rock and higher water column level diagenetic changes of the om were governed by bacterial activity rather than thermal alteration biomarker pattern does not significantly differ in serbian coals of different ages the main differences between upper middle and lower miocene coals are expressed by higher gelification index gi proxy ratio p aq n c 23 n c 27 n c 31 and pimarane 16 h phyllocladane ratio as well as lower relative abundance of c 31 r hopane of the latter one om of lower miocene coals is more mature corresponding to immature early mature stage huminite vitrinite reflectance 0 45 whereas om of upper miocene lignites is in immature diagenetic phase huminite reflectance 0 3 consequently higher gelification of lower miocene coals is probably an effect of higher rank however high humidity wet climate and low acidity within the mire could not be excluded a good correlation between biomarker parameters and paleoclimate data is observed indicating that biomarker patterns represent a valuable tool that reflect even slight paleoclimate changes in serbia during miocene

petrological and organic geochemical properties of lignite from the kolubara and kostolac basins serbia implication on grindability index abstract the influence of different coal lithotypes on grindability has been investigated using lignite from two of the most important upper miocene lignite basins in serbia kolubara and kostolac yellow xylite rich types demonstrated the most negative impact on hardgrove grindability index hgi all different types of xylite rich coal as well as total xylite rich coal from the kolubara basin have a negative influence on the grindability properties while only the yellow type of xylite rich coal from the kostolac showed a negative impact on hgi matrix coal does not show a clear effect on hgi a negative correlation between textinite content and hgi is observed in both basins whereas contents of other macerals do not show influence on grindability properties content of total organic carbon demonstrated the negative impact on hgi correlation analysis indicates that the negative impact of the yellow type of xylite rich coal and the sum of total xylite rich coal on the grindability properties partly can be related to content of total organic carbon and high amount of soluble organic matter matrix lithotype does not show any significant correlation with bulk geochemical parameters in both basins the peat forming vegetation of all samples from both basins were dominated by decay resistant gymnosperm coniferous plants belonging to one or several of the families taxodiaceae podocarpaceae cupressaceae araucariaceae phyllocladaceae and pinaceae lignite from the kolubara basin is characterized by a higher contribution of angiosperm vegetation than coal from the kostolac basin peatification of the kolubara coal occurred under more oxic conditions than the kostolac one analysis of biomarkers indicated that the negative impact of all types of xylite rich coal from the kolubara on hgi can be related to the higher proportion of angiosperms abundance of mid chain n alkanes and sesquiterpenoids aromatization of non hopanoid triterpenoids and hopanoids and intense degradation of wood tissues in a more oxic environment the positive impact of matrix coal on hgi in the kolubara samples can be attributed to elevated content of non aromatic hopanoids and low amounts of aromatic non hopanoid triterpenoids and sesquiterpenoids which seems to hinder the grindability properties

novel polar biomarkers of the miocene maritza east lignite bulgaria abstract the present study provides further insight into the composition of polar compounds in the miocene maritza east lignite bulgaria samples from two coal seams and interbedded claystone layers have been analyzed by geochemical proxies for polar constituents consisting of n alkan 2 ones n alkanols n alkanoic acids polar sesqui di and triterpenoids steroids hopanoid acids etc these series are quantified correlated vs depth and various ratios calculated polar diterpenoids predominate in the soluble organic matter several new compounds were identified i e 7 11 dehydro 12 oxoabieta 7 9 11 13 triene salvinolone and chamaecydins the preferential contribution of cupressaceae taxodiaceae in the palaeoflora is confirmed by the significant abundance of polar diterpenoids 200 600 g g c org and is further supported by the presence of chamaecydins 3 9 g g c org the polar lupane assemblage attests that betulaceae also was an important input from angiosperm vegetation to the palaeomire the related new compounds are 24 25 bisnoroxyallobetula 1 3 5 10 triene and 24 25 bisnorallobetula 1 3 5 10 triene which further support this point this investigation increases the knowledge on floral progenitors and provides further proof of the input from the cupressaceae taxodiaceae or podocarpaceae families as the most abundant trees in the peat forming environment of the miocene maritza east basin

polar aromatic biomarkers of miocene aged chukurovo resinite and correlation with a progenitor macrofossil abstract functionalised aromatic constituents of chukurovo resinite are compared here with the chemical composition of a macrofossil assigned paleobotanically as taxodium dubium sternb heer terpenoids and lipids of fossil wood tissue embedded in a clay sediment were extracted and analyzed for comparison the information was interpreted in relation to the biomarker compositions of different conifer families as well as to the effects of contamination by inward migration of organic matter from the adjacent sediments many of identified geolipids i e alkanes alkanols alkan 2 ones and steranes triterpanes have no chemosystematic value because they are ubiquitous in the plant kingdom ferruginol sugiol and products of their diagenetic transformations were identified as the dominant specific biomarkers in the resinite ferruginol and its analogues were the most abundant diterpenoids in taxodium dubium sample thus the biomarker composition of the extractable matter of the resinite strongly suggests that species of cupressaceae contributed significantly to the chukurovo paleoenvironment

petrographyof some fraser river delta peat deposits coal maceral and microlithotype precursors in temperate climate peats abstract peat deposits on the recent lobe of the fraser river delta british columbia have accumulated in a variety of depositional settings the study of the decomposition of the plant components associated with each depositional area has enabled prediction of the occurrence and distribution of the precursors of the loal macerals and microlithotypes on inactive portions of the distal lower delta plain thin sedge grass peats ave developed these peats were influenced by marine conditions near the base and freshwater conditions higher in the section a high ratio of cellulose to lignin in marsh plants and limited exposure of these tissues to desiccation and oxidation prodcue primarily desmocollinite smaller amounts of cernite cutinite and alganite origginate from algal and sedge lipids in the transition to freshwater peats oxyfusinite pyrofusinite and micrinite partially replace former exinite and vitrinite group maceral precursors subsequent transgression by marine waters has further promoted decomposition of the peat laterally extensive but thin and discontinouus coal seams which would develop from such peat will contain vitrite bands near the base and grade upsection into interlamlaminated durite and vitrinertite peats deposited between the upper and lowerdelta plain originate from brackish water as such earliest peat horizons contain similar maceral compositions to thoce encountered in distal delta plain deposits crevasse and fire splays disrupt gradational changes in fabric upsection and along channel margins flooding by oxygenated neutral ph waters followed by extended periods of desicaation result in increases of inertodetrinite macrinite sclerotinite and oxyfusinite interlaminated durites and vitrinertites will form common microlithotypes interbedded bands of telinite cutinite and cerinite are produced by later freshwater sedge grass peat accumulations in this biofacies clarite replaces durite after colonization by sphagnum lignin rich tissues from ericaceous shrubs and pinus contorta provide precurssors for subernnite telocollinite and telinite stumps of massive telinite interrupt these banded macerals coal seams originating from such peats would be thick laterally extensive and characterized by vitrite with laminae of liptite and lenses of clarite in the upper part

depositional environment of the lower cretaceous muling formation of the laoheishan basin ne china implications from geochemical and petrological analyses abstract the laoheishan basin located in northeastern china is filled with non marine coal and oil shale oil prone mudstone sediments of the lower cretaceous muling formation based on petrological mineralogical and geochemical methods the depositional environment during organic matter om accumulation is investigated for the first time the coal is subbituminous in rank petrological and bulk geochemical data indicate sapropelic coal deposited in low lying mire under freshwater conditions high pristane phytane ratios provide evidence for a land plant origin of om and oxic conditions during deposition a neutral to slightly alkaline ph is reflected by the presence of carbonate high liptinite contents and terpenoid biomarker composition indicate high amounts of resinous om during oil shale deposition a raised water table was favorable for om preservation under oxic to dysoxic conditions the oil shales in the lower unit of the succession not associated with coal are characterized by high hydrogen index and resinite contents interpreted to reflect deposition at elevated water depths in contrast to the findings of previous studies on oil shales in china indicating its origin from algal om a predominance of terrigenous om rich in waxy and resinous lipids is implied from biomarker and maceral composition the lower cretaceous oil shale and coal in the laoheishan basin contain high amounts of land plant derived terpenoid biomarkers derived from coniferales e g pinaceae cupressaceae taxodiaceae araucariaceae podocarpaceae and ferns the results are in agreement with palynological data the data highlight the potential of resinous and waxy om to form excellent hydrocarbon source rocks

effects of weathering on organic matter abstract bulk geochemical petrographical mineralogical and molecular compositions of unweathered weathered and transitional zones of a middle jurassic fossil wood were analyzed to trace changes caused by oxidative weathering of the immature terrestrial organic matter om the occurrence of such zones was confirmed by the mineral composition showing replacement of siderite and pyrite by goethite vitrinite reflectance analysis of weathered and unweathered fossil wood samples revealed that weathering elevated the vitrinite reflectance values by ca 0 1 which should be taken into account during modeling of low maturity terrestrial om in the weathered part of the wood most of the biomarkers and biomolecules were totally removed or the concentration decreased significantly the concentration of most of the polynuclear aromatic hydrocarbons pahs decreased by 50 80 being 90 for the more reactive and less stable benzo a pyrene and perylene on the other hand several aromatic compounds like phenanthrene and its methyl derivatives phenyl naphthalenes fluoranthene and oxygen containing aromatic compounds increased in concentration in the weathered zone this results from processes such as formation of phenyl derivatives of pahs and their cyclization as well as aromatization of diterpenoids and incorporation of oxygen into aromatic structures weathering should always be considered in studies of fossilized terrestrial om especially in the case of thermal maturation modeling because it significantly decreases the om content and total sulfur content changes vitrinite reflectance values and alters the extract composition as a result of organic compound degradation

palaeoenvironment assessment of pliocene lom lignite bulgaria from bitumen analysis and preparative off line thermochemolysis abstract the dacian coal bearing province is located in nw bulgaria coal formation is thought to be connected with desiccation of the dacian basin during a prolonged regression in the late pontian and pliocene dacian romanian age a lom lignite sample was characterized via micropetrography bulk chemical analysis spectral methods and thermochemolysis the pollen record was poor suggesting coal formation under oxygen rich conditions during peatification straight chain alkanes alkan 2 ones alkanols des a triterpenoids aromatized triterpenoids aromatized hopane hopene hopanes and triterpenoids with a strong dominance of oleanane derived structures were present in the extracted bitumen the residue after extraction was subjected to preparative off line tetramethylammonium hydroxide tmah thermochemolysis the aliphatic products released were c22 c27 fatty acid fa methyl esters i e methoxymethyl esters c22 c28 even numbered diacids dimethyl esters with a smooth distribution and traces of i and ai c15 acid methyl esters trapped and bound fas were distinguished using tetraethylammonium acetate teaac treatment the main thermochemolysis products were phenols structurally related to lignin vanillyl and syringyl units were produced in similar amounts indicating nonwoody angiosperm vegetation as the main plant input to the palaeo swamp probably originating from marsh or grassland sources the bitumen provided unequivocal information for an angiosperm contribution to the mire while the results of the tmah pyrolysis revealed a concomitant angiosperm and gymnosperm input the biomarker assemblage makes the lom lignite unique in bulgaria all the other bulgarian neogene lignites being dominated by coniferous vegetation with only traces of angiosperm contributions

reconstruction of floral changes during deposition of the miocene embalut coal from kutai basin mahakam delta east kalimantan indonesia by use of aromatic hydrocarbon composition and stable carbon isotope ratios of organic matter the distribution of aromatic hydrocarbons and stable carbon isotope ratios of organic matter in a series of nine miocene embalut coal samples obtained from nine coal seams of kutai basin east kalimantan indonesia were studied the rank of the embalut coals ranged from lignites to low rank sub bituminous coals 0 36 0 50 rr based on measurements of huminite reflectance the aromatic hydrocarbon fractions of all coal samples were dominated by cadalene in the lower boiling point range and picene derivatives in the higher boiling point range of the gas chromatograms cadalene can be attributed to the contribution of dipterocarpaceae and various hydrated picenes to the contribution of additional angiosperms to the coal forming vegetation the picenes originate from alpha and beta amyrin however in some coal samples minor amounts of simonellite and retene were also detected which argues for an additional contribution of gymnosperms conifers to coal forming vegetation preferentially in the middle miocene and at the beginning of the late miocene the results of stable carbon isotope ratios d 13

the petrographical and organic geochemical composition of coal from the east field bogovina basin serbia abstract a petrological and organic geochemical study was performed on coal samples from the east field deposit bogovina basin serbia fourteen coal samples were collected from different parts of the main and upper coal seams from fresh working faces in the underground subbituminous coal mine the lower miocene coal of the east field is a typical humic coal with huminite liptinite and inertinite concentrations of up to 81 4 vol 16 1 vol and 13 5 vol respectively densinite is the most abundant maceral with variable amounts of ulminite and gelinite sporinite and liptodetrinite are the most common macerals of the liptinite group exsudatinite was detected in the lower part of the lower coal seam inertodetrinite is the most abundant maceral of the inertinite group the mineral matter consists mostly of clay minerals and carbonates the mean random huminite reflectance ulminite b for the main coal seam is 0 42 0 04 rr and 0 41 0 04 rr for the upper coal seam which are typical for an immature to early mature stage of the organic matter the distribution and abundance of n alkanes and steranes indicates a significant contribution of epicuticular waxes from higher plants high amount of phyllocladane type diterpenoids 16 h phyllocladane suggests that coal forming plants were conifer families taxodiaceae podocarpaceae cupressaceae araucariaceae sciadopityaceae and phyllocladaceae while a higher amount of pimarane and norpimarane suggests pinaceae taxodiaceae and cupressaceae the pristane phytane pr ph ratio implies variable anaerobic to oxic conditions during sedimentation the distribution of the hopanes detected in the bogovina east field coal indicates an immature to early mature stage of the organic matter which is in agreement with huminite reflectance the high coal sulphur contents from the east field are characteristic for slightly alkaline depositional environments generated by bentonite from the basement of the main coal seam the petrological observation and biomarker composition provide evidence for the generation of immature hydrocarbons which most probably originated from the resins and waxes of higher plants mostly gymnosperms

influence of floral assemblage facies and diagenesis on petrography and organic geochemistry of the eocene bourgas coal and the miocene maritza east lignite bulgaria abstract numerous differences in the petrography and organic geochemistry of two tertiary low rank coal deposits of bulgaria formed within comparable depositional environments are outlined different floral assemblages are indicated as the main sources of organic matter for the eocene bourgas sub bituminous coals a warm climate plant community dominated by angiosperms is reflected in the biomarker composition whereas a coniferous flora was the main source of the resinous organic matter of the miocene maritza east lignite the results are in agreement with palaeobotanical data these differences in the peat forming vegetation of the paleogene compared to the neogene of bulgaria are attributed to decreasing temperature during the tertiary the abundance of resinous compounds relative to lipids from plant waxes long chain n alkanes as well as the preservation of plant tissue are mainly controlled by gymnosperm angiosperm ratios pristane phytane and diasterenes sterenes ratios reflect variations in redox conditions and the ph of the depositional environments caused by eustatic sea level changes freshwater inflow or varying ground water table changing eh and ph values are associated with differences in microbial activity controlling the extent of gelification of plant tissue bacteria most probably contributed to the aromatisation of triterpenoids in the mire enhanced thermal maturation of organic matter during diagenesis is reflected in higher contents of n alkanes and the presence of alkyl naphthalenes in the bourgas coals alkyl naphthalenes are thought to have been formed from pentacyclic triterpenoids rather than from resinous compounds

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

preservation of an ancient grassland biomarker signature in a forest soil from the french massif central in response to the lack of studies focussing on the residence time of molecular biomarkers in soils the lipid content of three soil profiles from the french massif central with different land use history were examined the free neutral lipid content of two reference soil profiles developed under grassland and forest vegetation and of a former grassland soil converted to forest about 60 years ago was analysed using gas chromatography mass spectrometry gc ms wax esters as well as the ratio of major homologues of n alkanes and n alkan 2 ones could be used to characterize the overlying vegetation in the reference forest and grassland soil profiles but failed to distinguish the respective grassland and forest contributions to the profile of the soil that had changed use for n alkanes and n alkan 2 ones the failure might be attributed either to mixing of the molecular patterns inherited for the former and current plant cover whereas for compounds such as wax esters simple degradation is likely to be involved conversely iso and anteiso c15 0 fatty acid methyl esters fames of bacterial origin steroids tracing cattle faecal contamination tricyclic diterpenoids and their oxygenated derivatives as well as methoxyserratenes inherited from pinaceae and triterpenyl acetates specific to the asteraceae proved to be effective in distinguishing current land use for the reference soil profilesand for the converted soil the persistence of these compounds in the changed use soil allowed us to estimate their residence time in soil

molecular composition and chemosystematic aspects of cretaceous amber from the amazonas araripe and reconcavo basins brazil amber occurrences in brazil are rare in this regard the molecular composition of three such fossil resin samples from brazilian cretaceous sedimentary basins has been analyzed to determine the botanical origin of the resins the samples were collected from the amazonas alter do chao formation araripe santana formation crato member and reconcavo maracangalha formation caruacu member basins the mono sesqui and diterpenoids in the extracts were used as chemosystematic markers when compared with terpenoids in extant conifers the compounds were mainly diterpenoids and their degradation products from the labdane podocarpane pimarane and isopimarane classes in addition to paraffins methoxyphenols and carboxylic acids tetracyclic diterpenoids such as phyllocladane kaurenol and kauranol were also present the biomarker compositions are certainly typical for conifers and given the absence of triterpenoids and diterpenoids such as ozic acid angiosperms can be excluded as a botanical source the absence of phenolic diterpenoids ferruginol totarol and their derivatives excludes podocarpaceous affinities for the ambers from the amazonas and araripe basins the fossil records of the embedding sediments e g araucariaceae pollen and leaves support the proposal of an araucariacae origin for these ambers but cupressaceae and cheirolepidiaceae cannot be excluded on the other hand the presence of phyllocladane and kaurane derivatives is evidence for araucariaceae or podocarpaceae origins for the amber from the reconcavo basin but cupressaceae cannot be excluded