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

the pre quaternary history of fire abstract although evidence for land vegetation comes from the silurian and maybe even earlier the first record of fossil charcoal fusain is from the late devonian for this period there are only one or two isolated records not until the early carboniferous is there a record of extensive charcoal deposits mainly preserved in near shore clastic sediments which provide evidence of significant and widespread wildfires by the late carboniferous charcoal was common or abundant in a wide range of facies including tropical wetland peats wildfire played an important role in shaping the environment at this time the latest palaeozoic and early mesozoic records of charcoal are fewer whereas important deposits of late mesozoic age are found worldwide the occurrence of charcoal at the cretaceous tertiary boundary has been highlighted as evidence for a global fire following a meteorite impact but this interpretation is questionable charcoal has been widely reported from tertiary sediments and its appearance in the quaternary and recent is not solely as a result of human impact through the past 400 million years there have been major changes in atmospheric oxygen levels that affected fire intensity and frequency fire systems thus have a long history and their impact on shaping the environment is assessed

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

petrological and organic geochemical investigation of recent peats with known environments of deposition abstract a series of recent peat samples from tropical sub tropical and temperate locations were investigated using coal petrographical and organic geochemical techniques maceral and biomarker compositions were examined to see if they correlated or diverged from the known environment of deposition of the peats the proportion of humotelinite was related to the water depth and the frequency of dry periods the ph and trophic level have a modifying influence on the preservation of tissues furthermore the proportions of sclerotinite in the peats seem to reflected the oxygen status in the mire which was also mirrored in the abundance of humic and fulvic acids a facies diagram was calculated for the peat samples to see how maceral indices would fare in interpreting their known environments of deposition the results proved to be generally unsuccessful as the herbaceous and woody peats did not always give the predicted high humodetrinite and humotelinite compositions respectively the aliphatic hydrocarbon fraction from the extracts of the peat samples show that mainly odd numbered n alkanes are present diterpenoids triterpenoids and hopanoids were found in most samples and were mainly unsaturated in nature the relative proportion of hopanoids in pears appears to be related to bacterial activity in acidic environments de a triterpenoids were also detected in the peat stage of diagenesis in an angiosperm dominated peat type mariscus polycyclic aromatic triterpenoids were present in the aromatic fraction of the extract their occurrence and proportion appears to be related to the degree of humification in a taxodium peat mono di and triaromatic diterpenoids were detected the presence of these aromatic biomarkers indicate the rapid formation of these compounds in the peat stage mainly mediated by microbial activity

changes in bulk properties and molecular compositions within new zealand coal band solvent extracts from early diagenetic to catagenetic maturity levels abstract the bulk properties and bitumen molecular compositions of a rank series of 38 humic coals from the new zealand coal band cretaceous cenozoic have been analysed to investigate early maturation processes affecting coaly organic matter through diagenesis to moderate catagenesis rank s r 0 0 11 8 r o 0 23 0 81 the samples comprise a relatively restricted range of vitrinite rich coal types formed largely from higher land plant material under relatively oxic conditions but with a significant contribution from microbial biomass with increasing rank total organic carbon contents show a general increase whereas moisture and asphaltene contents decrease bitumen yields also decrease through the stages of diagenesis and early catagenesis rank s r r o r 5 6 r o 0 40 as indicated by the constant occurrence and gradual increase of isoprenoids e g pristane and phytane and hopanoids in their more mature configuration this early phase of catagenesis not previously recognised in new zealand coals is followed at rank s r 9 r o 0 55 by the main catagenesis phase characterised by a more rapid increase in the generation of hydrocarbons including total n alkanes isoprenoids and hopanes changes in the maturity of new zealand coals can be traced by the carbon preference index and several hopane maturity parameters including 22 s 22 s 22 r and

observations on the nature and origin of fusain abstract evidence for a wildfire origin of fusain is examined charcoal produced by natural fires and artificial charring resembles fossil fusain both in physical size and shape and in optical reflectance artificially charred leaves and naturally burnt wood are illustrated using the sem reflectance studies on modern charcoals suggest that much semifusinite may be produced by pyrolysis the ecological implications of a wildfire origin of fusain are discussed and it is concluded that fires have been a feature of terrestrial ecosystems from at least the late devonian

unusual distributions of long chain n alkanes and n alkenes in antarctic soil abstract hydrocarbons in soil samples from the mcmurdo dry valleys of southern victoria land antarctica were studied to examine their features and to elucidate source materials normal alkanes and n alkenes were found at concentrations ranging from 13 to 2200 and from 1 1 to 5000 ng g of dry soil respectively unexpectedly the major hydrocarbons were all odd carbon numbered long chain n alkanes with maximum concentrations n c 23 n c 25 or n c 27 this may be due to the erosion of sedimentary materials containing vascular plant debris formed during the pre and inter glaciation periods of antarctica miocene pliocene and microbial debris such as fungi and microalgae normal alkenes maximize at n c 23 1 carbon chain length number of double bonds n c 25 1 n c 27 1 or n c 29 2 which could be derived from cyanobacteria and microalgae that lived in the past in the antarctic cold desert and or organic debris of wind transported cyanobacterial mats

the petrology organic geochemistry and palynology of tertiary age eureka sound group coals arctic canada abstract tertiary age lignites from arctic canada were analysed by petrographical palynological and organic geochemical methods results from petrographic analyses indicate the predominance of wood derived macerals humotelinite group in seams from the strathcona and stenkul fiord areas whereas in the bache peninsula area many seams are characterized by the predominance of detrital macerals humodetrinite and have also higher inertinite contents palynological assemblages are dominated by taxodiaceae pollen whereas pinaceae pollen and pteridophyte spores are less common angiosperm derived pollen contents are quite variable organic geochemical results indicate that norisopimarane and pimarane are the most abundant diterpenoids cadalene was present in the aromatic fractions of all samples with other components such as simonellite and retene in variable abundance rock eval data obtained from stenkul fiord area samples indicate low petroleum generation potential for this predominantly woody material the depositional environment at strathcona and stenkul fiords was that of a forested swamp which formed in a lagoonal alluvial plain setting palynomorph assemblages petrographic indices and the abundance of diterpenoids suggest that the mire flora was dominated by gymnosperms although locally angiosperms may also have been abundant as indicated by the occurrence of tetra and pentacyclic aromatic hydrocarbons at bache peninsula the mire was less forested as indicated by palynological assemblages typical for a marsh environment and petrographic characteristics such as low tissue preservation and the abundance of detrial macerals

paleogeographic evolution of the late miocene lake pannon in central europe abstract the paleogeographic evolution of lake pannon within the pannonian basin is reconstructed with eight maps ranging from the middle miocene to the early pliocene the maps are based on the distribution of selected biozones and specific fossils and on complementary sedimentological and seismic information our reconstruction shows that the history of lake pannon can be divided into three distinct intervals an initial stage with low water level which resulted in isolation from the sea at about 12 ma and might have led to temporary fragmentation of the lake an interval of gradual transgression lasting until ca 9 5 ma and a long late interval of shrinkage and infilling of sediments that persisted into the early pliocene the deep subbasins of the lake formed during the transgressive interval in more basinward locations than the deep basins of the preceding sarmatian age the southern shoreline running parallel with the sava and danube rivers along the northern foot of the dinarides changed very little during the lifetime of the lake while the northern shoreline underwent profound changes

biomarkers of holocene buried conifer logs from bella coola and north vancouver british columbia canada abstract the biomarker compositions of a holocene seep oil liquefied resin originating from a buried log of douglas fir pseudotsuga menziesii from bella coola bc canada and a holocene pine wood pinus sp sample from north vancouver bc canada were analyzed using gas chromatography mass spectrometry gc ms the total extract of the bella coola sample contains the sesquiterpenoid derivative calamenene and diterpenoids of the labdane abietane pimarane and phyllocladane classes a novel series of successively degraded labdane derivatives labdan 15 oic acid norlabdanoic acids drimenoic acid was detected in the polar fraction and a diagenetic pathway is proposed aromatic abietanes are the major components in the neutral fraction the neutral fraction of the pine wood contains two sesquiterpenoids calamenene cadalene diterpenoids of the abietane pimarane isopimarane and kaurane classes and a series of steroids 18 norabieta 8 11 13 triene dehydroabietin is the major component among the predominantly aromatic abietanes based on the compositions of the terpenoids it is concluded that the diagenesis of the pine and douglas fir logs probably occurred under anaerobic conditions leading to reductive reactions such as decarboxylation of resin acids with concurrent oxidation reactions to form the aromatic derivatives

impacts of paleohydrological changes on n alkane biomarker compositions of a holocene peat sequence in the eastern european russian arctic coupled analyses of n alkane biomarkers and plant macrofossils from a peat plateau deposit in the northeast european russian arctic were carried out to assess the effects of past hydrology on the m

the role of minerals in the thermal alteration of organic matter iv generation of n alkanes acyclic isoprenoids and alkenes in laboratory experiments a series of pyrolysis experiments utilizing two different immature oil prone kerogens type i green river formation kerogen type ii monterey formation kerogen mixed with common sedimentary minerals calcite illite or na montmorillonite was conducted to study the effects of minerals on the generation of n alkanes acyclic isoprenoids and alkenes during laboratory simulated catagenesis of kerogen the influence of clay minerals on the aliphatic hydrocarbons is critically dependent on the water concentration during laboratory thermal maturation under extremely low contents of water i e dry pyrolysis where only pyrolysate water is present c12 range n alkanes and acyclic isoprenoids are mostly destroyed by montmorillonite but undergo only minor alteration with illite both clay minerals significantly reduce alkene formation during dry pyrolysis under hydrous conditions mineralwater 2 1 the effects of the clay minerals are substantially reduced in addition the dry pyrolysis experiments show that illite and montmorillonite preferentially retain large amounts of the polar constituents of bitumen but not n alkanes or acyclic isoprenoids therefore bitumen fractionation according to polarity differences occurs in the presence of these clay minerals by this process n alkanes and acyclic isoprenoids are concentrated in the bitumen fraction that is not strongly adsorbed on the clay matrices the extent of these concentration effects is greatly diminished during hydrous pyrolysis in contrast calcite has no significant influence on the thermal evolution of the hydrocarbons in addition calcite is incapable of retaining bitumen therefore the fractionation of n alkanes or acyclic isoprenoids relative to the polar constituents of bitumen is insignificant in the presence of calcite

the plant fossil record reflects just two great extinction events five great taxonomic extinctions the so called big five mass extinctions are widely recognized in life history at the end of the ordovician frasnian late devonian permian triassic and cretaceous all of them were originally identified in the marine fossil record and have been interpreted as the result of abrupt global environmental changes previous evidence has suggested that terrestrial biota were also subjected to ecological disruption during these events but it is unknown whether they suffered the same level of large scale taxonomic disruption as marine organisms here we show that the plant fossil record in fact only provides evidence of two mass taxonomic extinction events one through the carboniferous permian transition the other during middle late permian times this differs significantly from the mass extinctions recognized in the marine realm and suggests that vascular plants have a special capacity for surviving abrupt environmental changes

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

palaeoclimate and vegetation change in serbia during the last 30 ma abstract in the present study 14 published megafloras from the serbian cenozoic are analyzed with respect to vegetation type palaeoclimate and palaeogeographic settings the floras cover a time span from the oligocene to the late miocene the results obtained are compared with continental climate records from other parts of europe and discussed in the context of global climate change to obtain a quantitative palaeoclimate record a total of seven different climate variables is calculated for each of the floras using the coexistence approach it is shown that basic patterns of vegetation change such as the immigration of arcto tertiary deciduous floristic elements during the early miocene and the decreasing diversity of laurophyllous taxa during the late miocene are ruled by climate change and a changing palaeogeography the serbian cenozoic climate record shows a steep cooling gradient during the oligocene that is most probably is connected to a northward movement of tectonic plates the globally observed middle miocene climate optimum and the late miocene cooling are well reflected according to the palaeotemperatures calculated a warm temperate climate existed in serbia throughout the time span examined the late miocene cooling is most pronounced in winter temperatures and is connected to increasing seasonality precipitation rates obtained for the serbian cenozoic especially those of the warmest and wettest months tend to be lower when compared to the central european cenozoic according to climate analysis and the interpretation of vegetational data there is evidence for regionally drier conditions and increased seasonality of precipitation in the time span from the late badenian to the early sarmatian

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

magnetite as an indicator mineral in the exploration of porphyry deposits a case study in till near the mount polley cu au deposit british columbia canada the investigation of this paper focused on whether the composition of hydrothermal ore related magnetite in till could be used to locate porphyry deposits in terrane where glacial overburden overlies rocks that host porphyry cu au mineralization this hypothesis was tested using 20 till samples collected in a 900 km2 area surrounding the mount polley porphyry cu au deposit in south central british columbia canada at least 100 magnetite grains were randomly selected from the magnetic fraction of each till sample nineteen trace elements in 50 magnetite grains in each sample were measured by laser ablation inductively coupled plasma mass spectrometry la icp ms the large beam or raster size used for laser ablation to 100 m homogenizes any heterogeneous trace element distributions in magnetite that result from oxy exsolution and or and dissolution reprecipitation avoiding this issue with the few micron size of an electron beam linear discriminant analysis lda performed on a compilation of magnetite compositions measured by la icp ms from worldwide porphyry deposits and intrusive igneous rocks define the chemical signature mg al ti v mn co ni of hydrothermal magnetite exclusive to porphyry systems application of our two lda models to the 985 magnetite compositions we measured in the till samples surrounding mount polley showed anomalous amounts of hydrothermal magnetite grains in till up to 2 5 km west southwest and 4 km northwest of the deposit a pattern that is consistent with the ice flow history of the region our lda models for magnetite trace element compositions have strong potential to be an effective tool in exploration for buried porphyry systems

organic matter from the callovian middle jurassic deposits of lithuania compositions sources and depositional environments abstract this study presents the first organic geochemical and petrographical investigation of the callovian deposits of the eastern part of the central european basin it is shown that in both the terrigenous papil formation lower callovian and shallow to deeper marine facies of the papartin and skinija formations middle and upper callovian respectively terrestrial organic matter predominates this is reflected by the carbon preference index values higher than 1 2 for all samples and in some cases higher than 2 as well as the occurrence of characteristic higher plant biomarkers like cadalene dehydroabietane simonellite and retene moreover in the case of the papil formation sugiol a natural product terpenoid produced by distinct conifer families has been detected in clay sediments the occurrence of such a biomolecule in the middle jurassic clays is reported for the first time its occurrence is probably connected with the presence of small wood debris in the clay sediments in samples of the papil formation charcoal fragments co occurring with unsubstituted polycyclic aromatic hydrocarbons were detected indicating that wildfires took place during the early callovian of lithuania and or neighbouring areas in the middle and upper marine callovian sediments of lithuania there is no evidence of anoxic conditions occurring in the water column however periodic anoxic or strongly dysoxic episodes may have occurred most probably below the photic zone during the deepest phase of the late callovian transgression as is evidenced from pyrite framboid diameter distribution and general impoverishment of benthic fauna huminite reflectance r r values for the investigated area are in the range of 0 21 0 31 suggesting the occurrence of immature organic matter such values indicate that these investigated deposits were close to the surface during their whole diagenetic history and the thickness of younger cover did not exceed ca 500 m this is also supported by a biomarker analysis in which less thermally stable hopanes and hopenes significantly dominated

the ratios of dibenzothiophene to phenanthrene and pristane to phytane as indicators of depositional environment and lithology of petroleum source rocks abstract the ratio of dibenzothiophene to phenanthrene and the ratio of pristane to phytane when coupled together provide a novel and convenient way to infer crude oil source rock depositional environments and lithologies such knowledge can significantly assist in identifying the source formation s in a basin thereby providing valuable guidance for further exploration the ability to infer this information from analysis of a crude oil is especially valuable as frequently the earliest samples in a new area may be shows and or drill stem test samples from exploratory wells which are characteristically drilled on structural highs stratigraphically remote from the source formation s a cross plot of dibenzothiophene phenanthrene versus the pristane phytane ratios measured on seventy five crude oils from forty one known source rocks ranging in age from ordovician to miocene consistently classified the oils into the following environment lithology groups marine carbonate marine carbonate mixed and lacustrine sulfate rich lacustrine sulfate poor marine and lacustrine shale and fluvial deltaic carbonaceous shale and coal the dibenzothiophene phenanthrene ratio alone is an excellent indicator of source rock lithology with carbonates having ratios 1 and shales having ratios the dibenzothiophene to phenanthrene and the pristane to phytane ratios can also be used to classify source rock paleodepositional environments the classification scheme is based on the premise that these ratios reflect the different eh ph regimes resulting from the significant microbiological and chemical processes occurring during deposition and early diagenesis of sediments the dibenzothiophene phenanthrene ratio assesses the availability of reduced sulfur for incorporation into organic matter and the pristane phytane ratio assesses the redox conditions within the depositional environment interpretation of these ratios has been aided by quantitative biomarker analysis and by carbon isotope data for pristane and phytane obtained by gas chromatography isotope ratio mass spectrometry

miocene vegetation and climate dynamics in eastern and central paratethys southeastern europe abstract from the cretaceous to modern time the earth s climate system has changed repeatedly from a greenhouse to an icehouse the miocene appeared as the last warm episode in earth history prior to the establishment of large northern hemisphere ice sheets furthermore the miocene was characterized by both large scale marine transgressions and pronounced episodes of regressions e g opening and closure of marine corridors as well as appearance and disappearance of lakes and swamps the sea level changes and instability of the climate system strongly influenced not only marine ecosystems but also the terrestrial biota to throw new light on the miocene evolution of european ecosystems and climate dynamics we compared plant assemblages from southeastern europe palaeogeographically this area is a transitional belt between tethyan and paratethyan realms and it thus constitutes a crucial geographical position when one tries to comprehend the exchange pathways of various floristic elements appearance and evolution of steppe vegetation interaction between forest and steppe vegetation and of course the corresponding climates influencing the vegetation dynamics both macro and microfloristic plant associations were considered in our analysis large palaeofloristic and palaeocoenotic transformations occurred during the miocene the early to middle miocene flora is rich and diverse in thermophilous elements which formed polydominant mesophytic to hygromesophytic forests early miocene climate was warm and humid with mean annual temperatures mainly above 16 c and annual rainfalls over 1000 mm the middle miocene was the warmest period of the whole miocene with annual temperatures ranging from 17 c to 19 c and winter temperatures from 7 c to 12 5 c climatic changes after the miocene climatic optimum caused changes in floristic composition and vegetation structure the vegetation shows a decreasing trend in abundance of palaeotropic and thermophilous elements reduction of macrothermic elements and disappearance of evergreen laurel forests together with these changes is a corresponding increase in the role of arctotertiary species in plant communities and they became dominants in mesophytic forests the available data indicate that major vegetation changes occur in the late miocene this period is characterized by more diverse climatic conditions which were directed by global climatic changes and probably complicated by regional palaeogeographic reorganizations and tectonic processes slight cooling and some drying is recorded for the beginning of the late miocene followed by fluctuations of palaeoclimate parameters observed which display cycling change of humid dryer and warmer cooler conditions our study provides a new insights on the miocene vegetation and climate dynamics and evolution in southeastern europe

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

aliphatic and aromatic triterpenoid hydrocarbons in a tertiary angiospermous lignite abstract the hydrocarbon biomarker assemlage of a liptinite rich early tertiary angiospermous lignite has been characterized the biomarker fistribution for the lignite confirms the low maturity and previous paleobotanic interpretations the aliphatic hydrocarbon fraction consists predominantly of n alkanes showing a strong odd carbon predominance and numerous de a triterpenoids and triterpenoids derived from higher plants bacterially derived triterpenoids were represented primarily by homohopanes and hopenes the aromatic hydrocarbon fraction contains a series of mono di and triaromatic de a triterpenoids and mono tri and tetraaromatic triterpenoids derived from higher plants the concentration and abundance of monoaromatic triterpenoids containing one to three additonal degress of unsaturation have not seen previously observed in a single deposit as such a diagenetic scheme for angiosperm derived triterpenoids is presented which confirms and extends previous hypothesis

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

chemostratigraphic evidence of higher plant evolution in the taranaki basin new zealand correlation between palynological and biomarker records of higher plant development during the cretaceous and paleogene in taranaki basin new zealand is good gymnosperms particularly podocarps were the chief members of coastal plain swamp flora during the late cretaceous and contributed significant quantities of diterpanes often dominated by isopimarane to organic rich sediments angiosperms increased in relative abundance through the paleocene and became the dominant higher plants in the eocene their contributions to coaly sediments are characterized by various triterpanes particularly 18 h oleanane and its c24 a ring degraded counterpart this change in dominance of higher plant groups can be followed by the use of an angiosperm gymnosperm index agi based on the relative concentrations of selected triterpanes and diterpanes in mz 191 and mz 123 mass chromatograms plant biomarker distributions do not provide as precise age indications as do pollen assemblages but they may be more representative of the vegetation growing in a particular area of a peat swamp

petrographic composition and depositional environments of the pliocene velenje lignite seam slovenia abstract a pliocene lignite seam up to 160 m thick occurs in the velenje depression in northern slovenia it forms part of a non marine transgressive sequence petrographic data together with ash and sulphur content of samples from two boreholes one located in the central and the other in the marginal part of the seam have been used to study vertical and lateral coal facies variations in the central part the lignite seam overlies fluvial sediments facies critical macerals and petrographic indices suggest that the lower ash rich part of the seam unit i accumulated in a wet forest swamp in an alluvial plain setting later this environment was replaced by a dry telmatic forest swamp unit iia according to our interpretation a decrease in tree density in units iib and iic reflects a change to a bush moor the transition from unit ii to unit iii is characterized by a rapid water table rise which resulted in the establishment of a wet limnotelmatic forest swamp within unit iii the tree density decreases and the degree of gelification increases towards the top of the seam suggesting a transition to a fen type environment another rapid water table rise ended peat formation in the eutrophic topogenous mire and established open lacustrine conditions a calcium rich environment resulted in high ph values and is responsible for high sulphur lignites up to 4 on a dry basis in the upper part of the seam the ph values were controlled by the amount of the inflowing lacustrine water only thin ash rich topotelmites accumulated along the northern margin of the mire there the seam originated in a wet forest swamp and was separated by limnic and fluvial sediments from other organic rich horizons due to its closer vicinity to the pre tertiary carbonates the depositional environment was probably even more alkaline therefore the lignite shows a higher degree of gelification and is even more sulphur rich up to 5 5 on a dry basis

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

petrological organic geochemical and geochemical characteristics of coal from the soko mine serbia abstract a petrological organic geochemical and geochemical study was performed on coal samples from the soko mine soko banja basin serbia ten coal and two carbonaceous clay samples were collected from fresh working faces in the underground brown coal mine from different parts of the main coal seam the lower miocene low rank coal of the soko mine is a typical humic coal with huminite concentrations of up to 76 2 vol liptinite less than 14 vol and inertinite less than 11 vol ulminite is the most abundant maceral with variable amounts of densinite and clay minerals sporinite and resinite are the most common macerals of the liptinite group inertodetrinite is the most abundant maceral of the inertinite group the mineral bituminous groundmass identified in some coal samples and carbonaceous marly clay indicate sub aquatic origin and strong bacterial decomposition the mean random huminite reflectance ulminite b for the main coal seam is 0 40 0 05 rr which is typical for an immature to early mature stage of organic matter the extract yields from the coal of the soko banja basin ranges from 9413 to 14 096 ppm in which alkanes constituted 1 0 20 1 aromatics 1 3 14 7 asphaltenes 28 1 76 2 and resins 20 2 43 5 the saturated hydrocarbon fractions included n c15 to n c32 with an odd carbon number that predominate in almost all the samples the contents of n c27 and n c29 alkanes are extremely high in some samples as a contribution of epicuticular waxes from higher plants acyclic isoprenoid hydrocarbons are minor constituents in the aliphatic fraction and the pristane phytane pr ph ratio varies between 0 56 and 3 13 which implies anaerobic to oxic conditions during sedimentation the most abundant diterpanes were abietane dehydroabietane and 16 h phyllocladane in samples from the upper part of the coal seam diterpanes are the dominant constituents of the alkane fraction polycyclic alkanes of the triterpane type are important constituents of alkane fractions the occurrence of and type hopanes from c27 to c31 but without c28 is typical for the soko banja coals the major and trace elements in the coal were analysed using x ray fluorescence xrf and inductively coupled plasma mass spectrometry icp ms in comparison with world lignites using the geometric mean value the coal from the soko banja basin has a high content of strontium 306 953 mg kg higher values than the world lignites were obtained for mo 3 614 mg kg ni 8 119 mg kg se 0 884 mg kg u 2 642 mg kg and w 0 148 mg kg correlation analysis shows inorganic affinity for almost all the major and trace elements except for s which has an organic affinity