characteristics features and compaction of plant tissues traced from permineralized peat to coal in pennsylvanian coals desmoinesian from the illinois basin abstract plant tissues were traced from coal balls to coal to identify and distinguish their characteristic structures in coal and to determine compaction ratios for specific tissues comparison of average cell sizes of lycopod aerial periderm in coal ball peat and coal gave compaction ratios ranging from 7 1 to 19 1 some of this compaction took place by three dimensional contraction of the periderm so that the shapes of the cells in cross section were not greatly changed compaction ratios of other tissues ranged from 3 1 to 60 1 tissues traced into vitrinite include lycopod stem periderm stigmaria periderm diaphorodendron cortex myeloxylon pennsylvanioxylon wood and bark marattialean fern leaves psaronius outer roots and stigmaria rootlets tissues traced into fusinite or semifusinite include lycopod stem periderm myeloxylon and psaronius inner roots cordaitean leaves cordaianthus and marattialean fructifications were identified in coal and coal balls from the same layer the coal balls were from the herrin springfield and houchin creek coal members of the carbondale formation desmoinesian series pennsylvanian system and an unnamed coal in indiana equivalent to the murphysboro coal member in illinois staunton formation desmoinesian series pennsylvanian system thin sections and etched polished blocks were characterized by light and sem microscopy

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

coal maceral ratios as indicators of environment of deposition do they work for ombrogenous mires an example from the miocene of new zealand abstract maceral indices were applied to sub bituminous coals of the maryville coal measures as a means of interpreting environment of deposition very low amounts of inertinite and ubiquitous bituminite lead to difficulties in interpretation of the maceral ratios comparison with modern analogues suggests the theoretical basis for discrimination of mire type by maceral ratios is not well founded on the following grounds absence of well structured wood tissues does not imply the absence of arborescent vegetation inertinite formation may be unrelated to vegetation gelification is used in a geochemical sense and does not indicate groundwater table level as supposed for biochemical gelification detrital macerals often result from in situ fragmentation and not transportation

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

macro and micro factors affecting coal seam quality and distribution in southern africa with particular reference to the no 2 seam witbank coalfield south africa abstract petrographical and palynological coal quality investigations relating to variations in one of the best known and well researched coalfields in africa the witbank coalfield and one of the most commercially important seams within this coalfield the no 2 seam are highlighted in this paper the investigations were based on 14 channel samples covering a 40 20 km 2 area in the witbank coalfield the results indicate that the coals in the no 2 seam were formed at the stage of major change over from dwyka to ecca floras as illustrated by the progressive dying out of dwyka pollens and spores and the introduction of ecca floral elements this also suggests a rapid amelioration of climate over the period of peat accumulation following a period of continental glaciation furthermore it is proposed that the in seam horizons reflect fluctuating of cyclic environments probably due to changing water level and plant communities due to changing growth environments saccate pollens appear to occur in association with vitrinite rich microlithotypes trilete spores with inertodetrite and carbominerite rich microlithotypes and plicates with inertite semifusite inertodetrite microlithotypes acritarchs nonspinose are present in parts of the seam where inertodetrite is common and in association with unusual suites of trace and major elements possibly indicating changing geochemical environments in high groundwater conditions petrographic results indicate that the coals are medium rank hypobituminous and show wide variations in maceral mineral and microlithotype compositions both vertically and laterally on the basis of microlithotype and mineral group analyses investigations were undertaken to establish vertical subdivisions by the study of historical patterns and possible lateral correlations of these subdivisions in the area under investigation these methods were then compared with distribution of selected chemical and geochemical parameters the evidence suggests that a common sequence of major events and some minor events occurred during the accumulation of the no 2 seam as manifested by petrographic and palynological facies three major periods or zones are recognized these tepresent periods of relatively stability quiescence separated by major in seam disruptive events namely flood deposits bearing high proportions of detrital organic material or minor clastic sedimentation these zones are subdivided into several subzones representing periods of reworking local flooding or rise in ground water levels and or changing geochemical environments these events can be recognized throughout the area under investigation but the manifestation of these events varies from area to area depending upon topographic situation proximity to river channels valley flanks or palaeoshorelines degree of subsidence and compaction geochemical environment and length of time under a specific set of conditions thus channels in close proximity to one another or in similar positions relative to valley flanks or axes appear to be remarkably similar to one another direct correlation of stratigraphic zones and sub zones from sample site of sample site was therefore possible although the methods to achieve this are complex and require the support of several supplementary complementary interpretative techniques coal quality variations and distribution within the original seam are therefore explicable in terms of the detailed factors listed above

the sydney coalfield of nova scotia canada abstract in size production and remaining resources the sydney coalfield is the largest field in eastern canada it is nearly entirely submarine and extends from northeastern cape breton island to almost as far as newfoundland occupying an area estimated at 36 300 km2 during 205 years of mining some 410 million t have been produced and the total remaining demonstrated resources present in ten seams have been calculated at 1 800 million short tons t 1 short ton 0 907 t of this in situ tonnage about 300 million may be suitable for metallurgical purposes and 1 500 million t can be classed as thermal coal some 82 of the total estimate is contributed by four seams of which the harbour seam is the main producer the present annual production is between 3 and 4 million t and all mining is done in the submarine area the main problems with submarine mining are ventilation and haulage time the latter increases with the distance from the shore and results in reduced production a west to east cross section through five seams illustrates the development of coal and shows the phenomenon of depositional splitting and rejoining caused by the interaction of fluvial sedimentation and peat accumulation fossil rivers forming wants or wash outs in the coal seams are the principle geological obstructions to mining structural difficulties are minor as the field is only gently folded and no main faults are present all coal of the sydney field is classed as high volatile a bituminous but there are significant changes within and beyond this category these are related to the observation that the coalification is essentially post deformational this has resulted in an increase in rank with depth as well as regionally from west to east within the same seam coke stability data indicate that these rank changes are economically favourable because the coking characteristics of the coal improve with depth and towards the east petrographically a normal banded bright coal is represented consisting of alternating bands of vitrite clarite clarodurite durite and fusite durite bands occur sporadically rarely exceeding 3 cm and are present as inertinite rich durite and exinite rich durite the latter consists of a groundmass of matted exinite and some of these bands could be traced over a lateral distance of some 50 km within the harbour seam section microlithotype analyses show that within each seam section four coal facies types can be recognized namely the forest terrestrial moor ftm the forest moor fm the reed moor rm and the open moor om facies all coal seams of the sydney field have low ash yields which range from 5 to 9 however the sulphur content is generally high and varies between seams from 2 5 to 6 2 the average volatile matter content is 36 and calorific value averages 7 524 kcal kg 13 545 btu lb

observations and experiments on the origin and formation of inertinite group macerals the inertinite group macerals include fusinite semifusinite inertodetrinite macrinite micrinite and funginite and secretinite which together replace sclerotinite the macrolithotype fusain comprises fusinite and semifusinite and is now widely accepted as charcoal formed by wildfire activity however alternative origins for fusinite and semifusinite are still claimed this paper considers the use of the terms pyrofusinite degradofusinite rank fusinite and primary fusinite misleading while the definitions of the terms funginite and secretinite are also considered problematic observations made on modern wildfire derived and volcanogenic charcoal assemblages using reflectance and scanning electron microscopy together with experimental charcoalification studies demonstrate that most if not all inertinite macerals have acquired their optical and physical characteristics through the action of elevated temperatures the criteria for the identification of charcoals produced by wildfire and volcanic activity are outlined and the role of the petrographic nomenclature system is discussed

a reappraisal of kerogen formation abstract comparative microscopical and chemical studies of recognizable entities in kerogen and their extant counterparts suggest a new and simple mechanism of kerogen formation which clarifies the interrelationships between extant biomass kerogen and fossil fuels

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

the genesis of coal from the viewpoint of coal petrology abstract the genesis of the microscopic constituents of coal macerals and of maceral associations microlithotypes representing various coal facies is discussed in the light of recent advances that have been made in the study of coals and modern peats peat microscopy especially promoted the understanding of humification and biological gelification both of which are decisive for the genesis of huminites vitrinites in brown coals and hard coals respectively microbial activity during peatification has been documented by chemists microbiologists and petrologists and recently by electron microscopical observations in coals this activity leads to the incorporation of lipid substances into the humic matter and later influences the chemical physical and technological properties of vitrinites geochemical gelification transforms the huminites of brown coals into the vitrinites of bituminous coals and is probably caused by the onset of bitumen generation in coal in this process the hydrogel brown coal is transformed to the bitumogel bituminous coal coal as a source rock for oil has become an important research subject for coal petrologists and oil exploration the formation of more or less liquid bitumen and its later cracking to gaseous hydrocarbons leads to the coalification jumps of the macerals especially liptinites and vitrinites and to the generation of secondary macerals like exsudatinite bitumen and micrinite dead carbon bituminization in coal has been revealed by the use of fluorescence microscopy which also found the presence of new liptinite macerals bituminite fluorinite and exsudatinite and suggests a higher proportion of algal material in coals than was thought earlier the genesis of various types of inertinite macerals will probably become an increasingly important subject of research especially with regard to rank inertinites that seem to attain their high inertinitic reflectance initially during coalification besides the origin of macerals the origin of various coal facies in terms of maceral associations is considered in relation to the palaeogeographic depositional milieu the peat forming vegetation palaeoclimate water and nutrient supply acidity marine and calcareous influence and fire with examples from euramerican carboniferous coals gondwana coals and tertiary brown coals vegetation water and oxygen supply eh conditions are most important for the generation of coal facies vegetation has been reconstructed with the help of palaeobotany including palynology cuticular analysis and wood anatomy in brown coals and with the study of petrified permineralized peats preserved in coal balls the microscopical investigations of botanically recognizable plant remains isolated from coals or accompanying rocks has been especially informative however the results of palynological and cuticular analyses should be evaluated with caution considering the varying resistance of palynomorphs and cuticles and in the case of palynomorphs their possible extrapaludal origin microscopical studies of modern peats that were derived from different types of vegetation growing in different hydrological environments have been very helpful in interpreting coal facies especially in brown coals the much disputed origin of brown coal lithotypes is considered in detail for hard coals there seems to be agreement that coal layers rich in vitrites and liptinite poor clarite were deposited in wet forest swamps that microlayered liptinite rich clarites are sub aquatic humic muds and that inertinite rich durites represent oxidized peats the origin of liptinite rich durites is controversial either subaquatic muds or oxidized peats the latter perhaps from raised bogs a recent trend in the literature is the assumption that many if not all mineable coal seams have been deposited in raised bogs under ombrogenous oligotrophic conditions although raised bogs with a dense arborescent vegetation are known from borneo it seems not probable that most seams which were deposited in foredeeps or steadily sinking graben zones are of ombrogenous origin although a succession from relatively wet and eutrophic to relatively dry and oligotrophic conditions may be true for occasional seams but as in modern peats striking changes of coal facies are commonly caused by hydrological events e g inundations as a consequences of crevasses or of fires that burned the peat the origin of the inertinite rich gondwana coals is discussed in relation to their specific climatic conditions and a comparison with sub arctic peats is recommended coals influenced by marine and calcareous conditions are characterized by high contents of sulfur and pyrite as well as by hydrogen rich vitrinites with a relatively low reflectance and high fluorescence all due to a strong bacterial activity in peats of low acidity proposals for further research are made in the conclusions

relationships among macerals minerals miospores and paleoecology in a column of redstone coal upper pennsylvanian from north central west virginia u s a abstract two distinct paleoenvironments are represented in vertical succession in a column of redstone coal in north central west virginia as indicated by a study of 37 consecutive 3 cm 0 1 ft increments analyzed for ash yield petrographic composition low temperature ash mineralogy and palynomorph abundances abundance profiles were constructed for ash 12 petrographic components 3 minerals and 5 miospore assemblages the profiles and calculated correlation coefficients show close relationships between several constituents components that increased in abundance upward in the coal bed were a collinite type 50 microns in thickness cutinite and miospores affiliated with calamites herbaceous lycopods cordaites and herbaceous ferns components that decreased in abundance upward were a collinite type 50 m in thickness cutinite calamite and cordaite miospores and kaolinite significant correlations occurred between ash yield and the collinite types 50 and

groundwater transformation of a low sulfur to a high sulfur coal the harlem coal of the northern appalachian basin abstract the harlem coal is postulated to have been deposited in raised bog settings it was initially deposited as low sulfur peat but groundwater of a later origin altered portions of it to high sulfur coal the total sulfur content of 172 samples from 31 locations on a moisture and ash free basis have a quadrimodal distribution with two major modes at 0 75 s and 2 0 s multiple sampling and analyses at specific mine sites indicate that the addition of sulfur of a later origin occurred either laterally adjacent to sandstone channels or vertically adjacent to faults significant sulfur addition also occurred above clay partings at these sites the original low sulfur nature is preserved where the coal bed is isolated from descending groundwater by a thick impervious layer trace element analyses show high concentrations of mobile elements such as na and mn in the high sulfur coals

petrology and facies studies of the carboniferous coals at mabou mines and inverness in comparison with those of the port hood st rose and sydney coalfields of cape breton island nova scotia canada abstract the mabou inverness coal bearing section is exposed along the shores of small land areas that form part of the large carboniferous basin beneath the gulf of st lawrence the westphalian c and d section measures 930 m and contains 26 seams that are 0 3 3 8 m thick the coals have a rank of high volatile b to high volatile c bituminous with vitrinite reflectance values of 0 6 0 7 r max petrographic composition in terms of microlithotypes and macerals was determined on column samples of thirteen seams and is illustrated in percentage diagrams a normal banded humic coal is indicated in which the bright banded variety predominates average ash sulphur and volatile matter contents are resectively 12 4 3 7 and 39 on mineral matter free basis coal facies has been determined from the microlithotypes and is expressed in terms of forest moor fm reed moor rm and open moor om in addition whole seam facies designations are given also and are compared with those of the sydney port hood and st rose coalfields they show that at mabou mines the rm facies greatly predominates but at inverness the fm facies is the dominant feature as is the case at sydney while at port hood om conditions prevailed higher paleo groundwater tables at mabou mines and port hood are deduced from this and are supported by the presence of anthracomya bearing black shales marceral based facies plots suggest that the mabou coals originated in the piedmont zone of the hercynean foreland region possibly in a southern embayment bordered by upland areas further north however in the inverness area the coal swamps may have extended uninterrupted to the sydney field and may have covered the pre carboniferous cape breton highlands before their uplift in early permian time

discussion on the concepts in paleoenvironmental reconstruction from coal macerals and petrographic indices abstract organic facies analyses quantify the coal constituents and plot various associations to discriminate the paleoenvironment for coal bearing successions this allows the relation of coal composition to mire ecosystems or environments coal petrographic models are used extensively to reconstruct the nature of ancient peat forming environments many authors proposed relations between specific maceral assemblages and or micro lithotypes and peat forming environments the key controlling factors which affect peat environment include hydrogeology redox ph vegetation type clastic influx sedimentation and peat accumulation rate etc recent advancements in coal maceral study and organic petrology reveal the pros and cons of the available indices and models the main reasons for the failure of the petrographic models are oversimplification of the effects of humification on tissue preservation vs destruction the use of post diagenetic processes e g geochemical gelification in determining depositional environments changes in petrographic composition related to floral evolution geological age rank increase and compaction lack of distinction between different inertinite maceral in some models here the widely used petrographic indices and models are reviewed based on the observations of several workers and the applicability and concepts of paleo environmental reconstruction are discussed a multi disciplinary approach including petrography palynology chemistry etc has been recommended which is more logical and scientific than the exclusive use of petrographic composition for paleoenvironmental interpretation

new interpretations of the facies of the rhenish brown coal of west germany abstract new ideas concerning the understanding of the facies of the rhenish brown coal of west germany are discussed these new interpretations are based on a significantly larger number of samples and refined procedures for analysis within the field of paleobotany palynology coal petrology and organic geochemistry than were available to p w thomson and m teichmuller the light and dark bands in the coal are mainly the result of different degrees of plant decomposition the influence of the peat forming plant communities plays a subordinate role in the petrographical composition of these particular strata of the rhenish brown coal

phyterals of humic coals in the u s s r abstract the results of a study of plant remains found in coals of devonian to neogene age which were studied mainly by the method of phyteral analysis are presented most of phyterals discussed and illustrated in this paper are from coal basins in the u s s r however a discussion of occurrences of phyterals in coal basins worldwide is also included middle devonian coals contain fungal remains and phyterals of the enigmatic vascular plant orestovia the most characteristic phyterals of euramerican carboniferous coals are the following periderm of stems and rhizomes of lepidophytes wood and cortex of gymnosperms of uncertain systematic position rachides of pteridosperms and fructifications of spore bearing plants vitrinized phyterals predominate over fusinized phyterals in carboniferous coals in permian coals of gondwana and angarida vitrinized and fusinized woods bark tissues and leaves of pycnoxylic gymnosperms are characteristic phyterals differences in phyteral composition of early and late permian coals indicate that phyterals from vitrinized leaves were more dominant in late permian coals triassic coals rarely contain phyterals of known affinity jurassic and early cretaceous coals are similar in phyteral composition periderm and cork of conifers and ginkgoaceous plants are typical phyterals phyterals of vitrinized and fusinized gymnospermous wood played a significant role in these coals as well leaf phyterals usually compose layers of the paper and fall of leaves coals distinctive characteristics of phyteral composition of cenozoic coals are 1 wide distribution of lignitized woods 2 constant presence of well identified and very specific root remains 3 high content of plant attritus 4 commonly occurring and distinctive fungal phyterals further study of coal phyterals is suggested for correlation of coal seams and coal bearing strata and for the prediction of coal quality

organic petrology of an early paleocene coal zone wabamun alberta palynology petrography and geochemistry abstract an interdisciplinary investigation of a section through the early paleocene ardley coal zone at wabamun alberta reveals that there are distinct vertical variations in the palynological petrographical and geochemical properties reflecting changes in the original depositional environment palynological assemblages are dominated by taxodiaceaepollenites hiatus revealing that the original coal accumulating mires were inhabited by taxodiaceous vegetation subordinate palynomorphs include varied gymnosperm pollen other than t hiatus laevigatosporites spp fern spores of polypodiaceous affinity stereisporites spp mosses including sphagnum and osmundacidites sp family osmundaceae coal petrography reveals that these coals are inertinite rich abundant fusinite pyrofusinite along with semi fusinite and inertodetrinite comprise up to 65 of the maceral assemblages huminite macerals are predominantly eu ulminite b with lesser eu ulminite a densinite and geli huminite gelified huminite lacking any remnant cell structure liptinite macerals include resinite sporinite and cutinite thinner stratigraphically lower seams at wabamun seams nos 6 3 consist predominantly of bright coal with high huminite contents palynofloral assemblages are comprised of t hiatus with few abundances of other palynomorphs suggesting that the original depositional environment was low lying dominated by taxodiaceous vegetation and frequently flooded as evidenced by numerous shale partings high ash contents and relatively high sulphur percentages the thick no 2 seam displays a distinct dulling up petrographic profile resulting from increasing inertinite contents coupled with increased abundances of stereisporites spp this may be evidence of localized ombrogeny within the original wabamun mires and may support a genetic relationship between stereisporites sp and inertodetrinite the no 1 seam consists of abundant fibrous fusain rich coal modes of origin of this fibrous coal include extreme oxidation due to prolonged drought and possibly forest fires elevated ash contents within the nos 1 and 2 seams may be a result of this oxidation of organic matter and concentration of the inorganics as well as airborne volcanic ash as evidenced by numerous bentonite bands within these coals sulphur contents are extremely low as low as 0 05 reflecting a terrestrial depositional environment

charcoal recognition taphonomy and uses in palaeoenvironmental analysis abstract charcoal predominantly the product of wildfires is abundant in many sedimentary rocks deposited in a wide range of environments from terrestrial to marine it also occurs in some volcanic rocks this paper outlines aspects of charcoal formation both natural and experimental and briefly considers the taphonomic processes leading to a final assemblage this is done using examples from recent fires and through experimentation the ways in which charcoal assemblages are recognized in the field and extraction in the laboratory are also considered methods of charcoal identification are presented the range of charcoalified plant organs that can be found is discussed and a wide range of study methods outlined including light microscopy dark field light microscopy reflectance microscopy scanning electron microscopy and synchrotron radiation x ray tomographic microscopy emphasis in this paper is on the study of macro and meso charcoal above180 m finally there is a consideration of the broad use of charcoal from plant evolution studies fire history studies vegetation studies anatomical studies climate and atmospheric studies and the wider importance of charcoal for the earth and biological sciences charcoal is information rich but yet is an under utilized resource

bubble transport in rip currents a number of remote and in situ acoustical sensors were mounted in the surf zone off scripps pier la jolla california during march 1997 and used to characterize rip currents and their ability to transport bubbles offshore from the surf zone the bubble size distributions and air fractions at the injection point were measured using an acoustical resonator and a conductivity sensor right in the surf zone the offshore moving bubble plume was tracked with a multibeam 100 khz doppler sidescan sonar giving the spatial extent and offshore variability in the rip events as well as information about the surface wave field furthermore three acoustical resonators were mounted at 2 5 m depth 55 60 m farther offshore to probe the bubble field 300 400 s after injection these results are interpreted using models that include bubble buoyancy and dissolution rip current advection and the turbulent boundary layer which is represented by the christoffersen and jonsson 1985 formulation

phanerozoic concentrations of atmospheric oxygen reconstructed from sedimentary charcoal varying concentrations of atmospheric oxygen have affected the development of animals and the role of wildfire in ecosystems reconstructions of past oxygen concentrations from fossil charcoal constrain atmospheric oxygenation over the past 400 million years variations of the earth s atmospheric oxygen concentration po2 are thought to be closely tied to the evolution of life with strong feedbacks between uni and multicellular life and oxygen1 2 on the geologic timescale po2 is regulated by the burial of organic carbon and sulphur as well as by weathering3 reconstructions of atmospheric o2 for the past 400 million years have therefore been based on geochemical models of carbon and sulphur cycling4 5 6 however these reconstructions vary widely4 5 6 7 8 9 10 particularly for the mesozoic and early cenozoic eras here we show that the abundance of charcoal in mire settings is controlled by po2 and use this proxy to reconstruct the concentration of atmospheric oxygen for the past 400 million years we estimate that po2 was continuously above 26 during the carboniferous and permian periods and that it declined abruptly around the time of the permian triassic mass extinction during the triassic and jurassic periods po2 fluctuated cyclically with amplitudes up to 10 and a frequency of 20 30 million years atmospheric oxygen concentrations have declined steadily from the middle of the cretaceous period to present day values of about 21 we conclude however that variation in po2 was not the main driver of the loss of faunal diversity during the permo triassic and triassic jurassic mass extinction events

palaeohistological studies on miocene brown coals of central europe abstract the texture of peat forming plants is often excellently preserved in the miocene seam layers of the central european depression as the micropetrographic categories maceral and microlithotype are primarily based only on the optical properties and degree of coalification of the cell wall the additional consideration of histological characteristics is expected to bring about a considerable gain in knowledge regarding the petrographic description and facies interpretation of seam layers in the micropetrographic characterisation of some brown coal seams in germany the microlithotype group textite was used for textural descriptions the microlithotypes included in textite are defined by histological features and are comparable to phyterals the microlithotypes are 1 xylo textite tissue with histological characteristics of wood 2 marcoduria textite tissue of primary roots of conifer 3 peridermo textite cork tissue and bark parenchyme 4 phyllo textite leaf tissue in particular of conifers the various microlithotype proportions were determined by point counting a micropetrographic identification of the types of facies in the 2nd lusatian seam horizon was successful the facies types show a vertical recurrent succession the distribution of histological microlithotypes in seam profiles reveals asymmetric changes in contents of peridermo textite and marcoduria textite which correspond to facies successions the micropetrographic composition of facies successions both in the 2nd lusatian seam horizon and in the frimmersdorf seam of lower rhenish basin is similar

sedimentological and petrographical characteristics of cretaceous strandplain coals a model for coal accumulation from the north american western interior seaway abstract coal seams formed on many cretaceous wave dominated strandplain sediments in north america are characterized by great lateral continuity tens to hundreds of kilometres substantial thicknesses up to 12 m relatively low ash and sulphur contents the coals formed behind an active shoreline in areas undergoing subsidence due to shale compaction and dewatering the zone of peat accumulation was remote from the shoreline and storm tidal inundations and generally protected from fluvial flooding if the rate of subsidence was too great lakes formed and peat did not accumulate statistical evaluation of petrographic properties by correspondence analysis of the lower cretaceous coals show that the strandplain coals form distinctive petrographic groups that are characterized by relatively low vitrinite contents and high inertinite contents semifusinite and inertodetrinite dominate in the inertinite maceral group liptinite contents are negligible tissue preservation indices and gelification indices indicate for the strandplain coals a forest type paleodepositional environment in which a relatively low water table allowed the accumulation of oxidized and partly oxidized components fusinite and semifusinite significant amounts of detrital components such as inertodetrinite and vitrinite b are diagnostic that some transportation of the organic material took place prior to deposition comparison of coal facies and depositional environments from permian coals of australian show that the lower cretaceous strandplain coals have petrographic similarities to coals that were formed under regressive back barrier conditions in the permian due to differences in nomenclature previously interpreted regressive back barrier environments may be similar to the strandplain environments discussed here

the organic geochemistry of coal from plant materials to coal coalification is a process that transforms plant remains under the influence of time temperature and possibly pressure to a black generally lustrous solid organic fossil fuel having a very complex chemistry although much has been learned in the past two centuries on coal chemistry we still have little knowledge of the way plant materials undergo these transformations the problem has been the existence of adequate characterization tools the advent of some new tools for structural elucidation of macromolecules has led to some revised thinking on coalification originally thought to be a process involving the full degradation of plant remains and subsequent reconstitution of these remains the general consensus today is that the process involves a selective preservation of certain resistant plant components followed by some minor reorganization of the biopolymers that survive the major components of plants do degrade and the resistant ones often constitute only a small fraction of the original mass of the plant materials this paper examines the most recent literature concerning coalification and focuses on the chemistry associated with coalification of certain recognizable plant remains that have been at the center of research activity for the past two decades thus we examine the recent knowledge of the chemistry of resistant biopolymers in extant and fossil wood cuticles resins spores and algae knowledge that has been assembled to establish the reaction pathways towards coal macromolecules

coal petrology and anomalous coalification of middle and late pleistocene peat and soft brown coal from the tengchong basin western yunnan people s republic of china abstract in the tengchong basin western yunnan people s republic of china the absolute age of middle pleistocene soft brown coal is about 600 000 b p and late pleistocene peat part of which had been transformed into soft brown coal is about 75 000 to 10 000 b p the forma is the world s youngest soft brown coal thus this basin affords an opportunity for studying the transformation of peat to soft brown coal our study of early coalification is based on comprehensive methods including the following coal petrological techniques radiometric dating botanical methods sporopollen analysis electron probe epma scannign electron microscopy sem proximate and ultimate analyses and pyrolysis gas chromatography py gc in view of the fact that the most abundant information on premacerals and macerals is obtained from peat and soft brown coal we propose a revised classification system of macerals of soft brown coal which is also used for peat the premacerals and macerals of peat and soft brown coal from the tengchong basin are divided into four maceral groups the huminite liptinite liptohuminite newly proposed and inertinite maceral groups the liptohuminite group includes the macerals lying between liptinite and huminite maceral groups therefore in optical properties chemical composition technological properties and genesis these macerals show transitional characteristics there are also some new interpretations of the genesis of several macerals for example sclerotinite like phlobaphinite appears to have originated from the polyhedral cell tissue of teh endomycorriza of several kinds of plants the authors subdivide different types of microstructures of some macerals with the scanning electron microscope sem and use both sporo pollen analysis and microfluorescence photometry to determine some fluorescence regularities in early coalification the coalification of tengchong peat and soft brown coal is quite different from normal coalification in two respects 1 the coalification occurred during a brief period of time and 2 there are anomalous factors of coalification such as high paleogeothermal gradient introduced by volcanic activity and shallow burial thus we suggest the term anomalous coalification

a major fire event recorded in the mesofossils and petrology of the late permian lower whybrow coal seam sydney basin australia abstract petrographic and mesofossil analyses of plies from the late permian lower whybrow coal new south wales australia have revealed a significant fire event in both the swamp setting and the hinterland the fire event is characterised by a change in the maceral composition the seam during this interval being dominated by inertinite especially semifusinite following the fire event the mineral matter content of the coal increases this may be the result of increased run off and erosion in the hinterland due to destruction of vegetation this major fire event is also reflected in a change in the vegetation as represented by the mesofossil content of the seam prior to the fire event the seam contains abundant bisaccate taeniate pollen sporangia and seed like bodies of possible glossopterid affinity these are lost at the ply in which the fire event is recorded though seed like bodies become important again later the fire event also corresponds to a change in the megaspore content of the coal a new species appearing perhaps as a result of hydrological change following this major fire event a mineral rich ply was deposited which contains miospore masses of spores from fern like plants possibly representing a re colonisation event by rhizomorphs after vegetation death this evidence for a major fire and its implications for the origin of inertinites leads to the conclusion that throughout this and other permian gondwana coals fire was an integral part of the temperate mid high latitude southern hemisphere swamp ecosystem

hydrogeologic factors affecting gas content distribution in coal beds gas content in coal is not fixed but changes when equilibrium conditions within the reservoir are disrupted therefore gas content distribution in coal varies laterally within individual coal beds vertically among coal beds in a single well and within thicker coal beds major hydrogeologic factors affecting gas content variability include gas generation coal properties and reservoir conditions gas generation affects gas content variability on a regional scale whereas coal properties influence gas content distribution on a regional and local scale reservoir conditions affect gas content more locally within specific fields or individual wells the potential for high gas content is controlled directly by the amount of thermogenic and secondary biogenic gases generated from the coal which in turn are controlled by burial history maceral composition and basin hydrodynamics variability in mineral matter ash and moisture content sorption behavior among macerals diffusion coefficients and permeability result in heterogeneous gas content distribution gas content decreases with decreasing pressure and temperature and coal beds become undersaturated with respect to methane during basin uplift and cooling gas content generally increases where conventional and hydrodynamic trapping of coal gases occur and may decrease in areas of active recharge with downward flow potential and or convergent flow where there is no mechanism for entrapment

geological factors influencing the concentration of trace elements in the philippi peatland eastern macedonia greece abstract six peat samples obtained from the holocene and the weichselian of the philippi peat deposit eastern macedonia greece were analyzed for 48 trace elements by inductively coupled plasma mass spectrometry icp ms the ash contents of these samples were also determined most of the trace elements are associated with the minerals in the peat while ge mo pb se ta tl u and w display a greater affinity with the organic matter compared with crustal averages clarke concentrations the philippi peat is enriched in some elements ag as au cd mo se te u and w because of the respective mineralizations in the area the philippi peat is also enriched in cr cu mo pb sc sn t v y and zn in comparison with typical fen peats as well as in as cr mo se and u in comparison with typical coals climatic and hydrogeological conditions strongly influenced the peat forming environment resulting in a differentiation between holocene and weichselian peat generally the holocene peat contains lower concentrations of trace elements in the northern and southern part of the fen than the weichselian one the opposite trend is observed in the fen area close to the western basin margins

organics versus clastics conditions necessary for peat coal development abstract the absence or lack of detrital influx into ancient peat forming swamps is critical to the formation of low ash coal modern and ancient coal forming swamps of continental basins show a separation of peat and clastic sediments which is partially fault controlled in the african rift valleys as well as in the stephanian intermontane coal basins of france thick peat free from clastic input may be the result of tectonic activity in the paralic basins of morocco westphalian b and nigeria late cretaceous coal occur landward of the shoreline turnaround and are related to a relative high stand of the sea which curtailed detrital influx into the basins thus peat formation occurred during an early transgressive phase

the geology botany and chemistry of selected peat forming environments from temperate and tropical latitudes abstract peat has been studied in several geologic settings 1 glaciated terrain in cold temperate maine and minnesota u s a 2 an island in the atlantic ocean off the coast of maine where sea level is rising 3 the warm temperate u s atlantic and gulf coastal plains where sea level has changed often and 4 the tropical coast of sarawak malaysia and the tropical delta of the batang hari river sumatra indonesia most of these deposits are domed ombrotrophic or partly ombrotrophic bogs in which peat accumulation continued above the surface of the surrounding soil however the bogs of the u s atlantic and gulf coastal plains are comparatively not as domed and many have almost level surfaces in some bogs aquatic or semi aquatic plant materials accumulated replaced water in the depressions and formed a surface on which marsh or swamp vegetation could subsequently live die and accumulate in others the plant materials accumulated initially on level silt or sand surfaces supporting marshes or swamps as the peat dome formed plants growing on it changed from luxuriant ones near the base of the dome where nutrients were brought into the bog by surface and ground water to stunted ones at the top of the dome where the raised bogs are fed by nutrient poor precipitation the physical and chemical changes that take place in the sequence of environments from the pond stage of deposit development through the grassy marsh stage through the forested swamp stage and finally through the heath dome stage can be measured in terms of acidity and ash volatile matter carbon hydrogen nitrogen sulfur and oxygen contents as well as in the kind and distribution of trace elements the organic and inorganic contents of the deposits relate to geomorphology and geomorphology relates to their settings as models of coal formation some domed peat deposits may help in solving problems of distribution and character of ancient coal beds but clearly not all peat deposits are precursors of coal most holocene peat deposits are subject to destruction by erosion fire and decomposition through microbial and chemical oxidation before burial the best environments for coal precursors have biomass accumulation a continuously rising water table within the mass and minimum influx of clay and silt until preservation by burial the most suitable settings for future economic coal deposits are domed bogs that accumulate thick widespread peat having low ash and low sulfur contents the ombrotrophic peat deposits of tropical sarawak and sumatra are thick and extensive contain low ash and low sulfur peat and have high heating values they are considered to be the best tropical coal analogs because of their extent and chances of preservation the base of the peat is below adjacent river levels and chemical and structural conditions are favorable for accumulation

evaluating the extent to which wildfire history can be interpreted from inertinite distribution in coal pillars an example from the late permian kuznetsk basin russia abstract inertinite charcoal distributions in two randomly sampled in situ coal pillars seams 78 and 88 from the late permian kuznetsk basin siberia were analysed using petrographic techniques to determine palaeowildfire histories fire occurrence type and return interval in situ coal pillars are judged to be essential for this type of research as they retain information on the original inertinite distribution and maceral clast size ranges which can never be obtained from the crushed coals typically used for petrographic analysis the seams represent an ombrotrophic mire seam 78 and mire with mire lake seam 88 depositional settings but both environments show the same pattern of fire history charcoal is present in all lithotype units in both pillars both pillars contain episodic charcoal horizons representing local surface fires within the peat forming environment interspersed with frequent regional background fire events as shown by small scattered inertinite this paper presents an approach to calculating fire return intervals fri in these coal pillars by removing the thickness of less compactable charcoal horizons before calculating original duration of peat formation this is achieved by using a range of peat accumulation rates and peat to coal compaction ratios resultant mean fri ranges from 7 years extremes 0 5 to 143 years for a lithotype unit containing 4 horizons to 70 years extremes 5 to 1550 years for a lithotype unit with 2 horizons the mid range values both suggest shorter fire return intervals than seen in modern peat forming environments

low ash peat deposits from a dendritic intermontane basin in the tropics a new model for good quality coals many good quality thick low ash carboniferous cretaceous and tertiary coal deposits have dulling upward sequences that have been interpreted to be of ombrotrophic lowland coastal origin previous studies of potential modern analogues for thick dulling upward coal sequences have focused on tropical ombrotrophic coastal peats however most modern coastal ombrotrophic deposits would yield all bright coal seams new evidence from peat deposits of the southern intermontane tasek bera basin western malaysia reveals that thick low ash low sulfur peat may originate in narrow tributary valleys with moderately steep flank gradients these deposits may be favorable precursors to dulling upward coals in that they contain high wood and low ash content at depth and medium wood and slightly increasing ash content in the upper parts peat accumulation in the tasek bera basin began in mid holocene time during the past 4500 years 500 cm of low ash 40 cm white fluvial silty clay with wood fragments was deposited the clay rich sediments are overlain by limnic black mud sandy clay and dark brown mud rich peat up to 70 cm thick the ash content of the mud rich peat is as high as 31 wt the high ash peat is overlain by low ash sapric to hemic peat up to 5 m thick the basal 3 m of the peat deposits contain abundant logs and large woody fragments whereas the top 2 m have less hard wood but more arborescent fragments of palmae such as roots from pandanus atrocarpus the acrotelm top 50 cm has a low to medium ash content 10 wt with burial the deposits of southern tasek bera basin would yield a dendritic sediment pattern of sandstone shale carbonaceous shale and a dulling upward vitrain rich coal overlain by carbonaceous shale because of the dendritic nature of the tasek bera basin coal seams would most likely have a similar pattern as the carboniferous humic coal deposits of the black warrior basin in alabama usa however the good quality coals with dulling upward characteristics would be concentrated in the southern tributaries of the basin

coal petrology and the origin of coal macerals a way ahead the development of coal petrology and the establishment of a nomenclatural system have proved of major use both for the industrial utilization of coal and for the development of a broad understanding of coal formation and diagenesis the development over the past 30 years however of nomenclature that includes aspects of plant origin and process is a retrograde step e g pyrofusinite degradofusinite and funginite equally problematic is the use of prescriptive formulae to indicate coal origins this paper reviews some of the problems involved with coal petrology as it is usually practiced in addition new advances in organic geochemical techniques have led to a fuller understanding of the relationship of plants and coal macerals recent research on the origin of coal macerals is presented and there is a discussion of the problems and challenges facing coal petrologists a holistic approach to studies of the origin of coal and coal macerals which includes not only petrographic but also chemical and biological studies is advocated d 2002 elsevier science b v all rights reserved

paleobotanical and paleoecological constraints on models of peat formation in the late carboniferous of euramerica abstract the dominant plants of the late carboniferous lowland tropics were taxonomically and structurally distinct from those of any later time periods dominance was distributed among lycopsids ferns sphenopsids pteridosperms and cordaites and each of these groups had distinctive and different ecological preferences and amplitudes peat forming habitats were dominated by lycopsids throughout the westphalian with a significant cordaitean element in the middle westphalian during the stephanian tree ferns were dominant following major extinctions near the westphalian stephanian transition each of the major plant groups had distinctive architectures and tissue composition trees contributed up to 95 of the peat biomass and tree forms of lycopsids psaronius and medullosa lack good modern analogues the cordaites were the only woody plant group to contribute significantly to peat and then only during the mid westphalian structurally wood like lycopsid bark is the major woody tissue encountered in most westphalian coals tree ferns and pteridosperms were largely parenchymatous in construction the stigmarian root systems of lycopsids also were largely parenchymatous the tissue structure of these dominant plant suggests the need for extreme caution in the inference of mire ecological conditions or vegetational structure from coal petrographic data peat formed under arborescent ferns or pteridosperms or peat repeatedly exposed to decay and rerooting by stigmarian root systems of lycopsids would have a distinctly non woody signature and yet would have formed in a forested environment a summary is presented of the autecology and synecology of mire plants emphazing the structural framework provided by lycopsids during the westphalian certain constraints in the links between peat biomass and miospore palynology are discussed in terms of over representation under representation and non representation the formulation of smith s four phase hydroseral model is discussed and compared with more recent data available from plant paleoecology the current debate over an ombrotrophic vs rheotrophic origin of late carboniferous peats relies in large part on paleobotanical data almost entirely palynological in combination with petrographic analyses ecological studies of miospores and of coal ball and compression macrofossils and the linkage of miospores to source plants permit the re evaluation of mire successional models evidence for tree lycopsids sphenopsids pteridosperms and cordaites suggests growth mainly in rheotrophic mires tree ferns are likely candidates for growth in domed mires although evidence is ambiguous and some tree ferns clearly grew under rheotrophic conditions densospores produced by at least sporangiostrobus lycopsid subtrees have been considered diagnostic of ombrotrophic conditions abundant evidence refutes this simplistic interpretation and suggests broad ecological amplitudes for densospore producers including growth under rheotrophic conditions although plant fossils alone can not resolve most of the major debates in modern coal geology paleobotany does contribute significantly to our understanding of ancient mires an approach combining paleobotanical data with petrography sedimentology and geochemistry on a case by case basis is most likely to produce a clear picture

an extraordinary peat forming community on the falkland islands most of beauchene island in the south atlantic is covered by tussac the tussock forming grass poa flabellata lam rasp which has produced a deep accumulation of exceptionally dense peat during 12 500 yr the basal peat is lignitic yet it is several hundred times too young to be a true lignite during an ecological survey of the island in december 19801 one of us r i l s sampled an 11 m high peat face the age against depth profile in the peat is consistent with a constant proportional rate of decay of 1 1 2 2 10 4 yr 1 and a constant rate of addition of dry matter to the peat of 430 720 g m 2 yr 1 this rate of decay is within the range recorded for peats in corresponding latitudes in the northern hemisphere but the rate of addition of dry matter is about 10 times as great this is not easy to accommodate within current hypotheses about peat formation an unusual combination of biological physical and chemical circumstances may be the cause as the island is difficult to visit and no more information can be obtained in the near future we now report these results incomplete though they are

the inorganic chemistry of peat from the maunachira channel swamp system okavango delta botswana abstract the okavango delta is a large 18000 km2 low gradient 1 3600 alluvial fan situated in the semi arid kalahari basin of northern botswana seasonal floodwaters from tropical angola disperse on the fan creating both perennial 6000 km2 and seasonal 7000 to 12000 km2 swamps ninety five percent of this water is lost annually by evapotranspiration organic rich sediment peat is a major sediment of the perennial swamps peat formation commences during senescence of the plants when certain nutrients are recycled while others are lost by rainwater leaching further changes in chemistry occur during subaqueous decay of the plants which involve both gains and losses of constituents decaying plants trap detrital mineral matter which becomes an integral part of the peat the main sources and forms of inorganic matter in the peat are allochthonous kaolinite 40 and quartz 20 and both allochthonous and autochthonous phytolithic silica 30 several inorganic components fe k p na ca and mg which make up the remaining 10 are associated with the organic fraction ion exchange plays only a minor part in their uptake and it seems that these metals are taken up during bacterial activity in the peat the weight proportion of inorganic matter ash decreases downstream mainly due to a decrease in allochthonous mineral matter volume percentage also decreases but is low throughout generally less than five percent this study has revealed that the low quantity allochthonous mineral matter is the main reason for the long term survival of this ecosystem uptake of soluble ions by the peat is important in off setting evaporative concentration of metals

delineation of the distinctive nature of tertiary coal beds abstract floral character in mires has changed progressively through time in the carboniferous pteridophytes sphenophytes and lycophytes were dominant but by the permian gymnosperms were an important component of mire flora during the early mesozoic gymnosperms remained the characteristic mire vegetation together with pteridophytes and conifers became dominant during the jurassic cretaceous and paleocene vegetation are similar with taxodiaceous flora being important in mire vegetation from the eocene onwards however angiosperms were increasingly dominant in mire communities and in the miocene herbaceous vegetation began to play a significant role together with these changes in floral character at least three aspects of coal character also appear to vary sequentially with time and are distinctive in the tertiary 1 proportions and thickness of vitrain banding 2 coal bed thickness and 3 proportions of carbonised material a compilation has been made of data from the coal literature comparing older coals with those of the tertiary in order to give a perspective in which to examine tertiary coals it was found that only tertiary coals contain significant proportions of coal devoid of vitrain bands in addition tertiary coals are the thickest recorded coal beds and generally contain low percentages of carbonised material many less than 5 as compared to older coals it is interesting to note that paleocene coal beds are similar to cretaceous coals in that they tend to be thinner and contain higher proportions of carbonised material than do younger tertiary coals the absence of vitrain bands in some tertiary coal beds is thought to result from the floras dominated by angiosperms which are relatively easily degraded as compared to gymnosperms the thickness of tertiary coals may be related to an increase in biomass production from the carboniferous through to the tertiary as plants made less investment in producing lignin an energy intensive process in addition with less lignin in plants easier degradation of biomass may have facilitated nutrient recycling which in turn led to greater biomass production increased biomass production may have also diluted the carbonised material present in some tertiary peats leading to lower proportions in the coal another possible cause of decreased carbonised components in tertiary coal is that decreasing lignin content resulted in decreased charring during fires as lignin is particularly prone to charring a third possibility is that the carbonised component of peat may be concentrated during coalification so that tertiary coals generally of lower rank than mesozoic or paleozoic coals contain a smaller fraction of carbonised plant material it is not at present clear which of these mechanisms may have affected carbonised material in peat and coal but it is clear that lignin type and content has had an important role in determining peat and coal character since the paleozoic

anisotropic fragments in strongly folded and faulted coals from the rocky mountain area of southeast british columbia the mammoth coal seam in southeastern british columbia canada was structurally thickened to 100 m as a result of laramide folding and faulting samples from the coal seam examined using reflected light microscopy include thermally altered coal macerals their by products e g pyrolytic carbon and in addition heat affected preoxidized coke the heat affected residues are composed of material formed by friction produced from faulting of the coal bearing strata the pyrolytic carbon was formed from the distillation of coal and from coal tar pitch the occurrence of preoxidized heat affected vitrinite suggests that the mammoth coal seam was oxidized before faulting

petrographic characteristics and depositional conditions of eocene coals of platform basins meghalaya india abstract the coal deposits of meghalaya occur in the lakadong sandstone 25 250 m thick of eocene age the coal bearing formations are understood to have been deposited over platform areas in estuarine and lagoonal environments and subjected to recurrent marine transgressions and regressions during the eocene period there are three major groups of coalfields in meghalaya viz garo hills west daranggiri and siju coalfields khasi hills langrin and mawlong shella coalfields and minor coalfields laitryngew cherrapunji and bapung coalfields pillar coal samples have been collected from 10 seams at 15 locations and have been subjected to a detailed petrographic examination for their characterization an effort has been made to trace the path of their evolution based on coal petrography based models the quantitative petrographic analysis shows that these coals are vitrinite rich 45 0 92 9 mean 73 4 mmf basis with low concentration of inertinite 0 0 13 8 mean 3 0 mmf basis whereas the liptinite occurs in appreciable concentration 5 5 53 1 mean 22 5 mmf basis further these coals are rich in vitrite 51 6 100 mean 78 3 mmf basis the volatile matter from 38 5 to 70 0 d a f and vitrinite reflectance rom from 0 37 to 0 68 characterize these coals as per german din and north american classification approximately as sub bituminous c to high volatile c bituminous the occurrence of teleutospore single double and triple celled suggests that these coals have originated from a characteristic tertiary flora the maceral and microlithotype composition in the coal petrography based depositional models suggest that the coals of garo hills were formed in reed to open water swamps in telmatic to limnic conditions the coals of khasi hills were dominated by forest swamps and telmatic to limno telmatic conditions in addition the occurrence of large size resins suggests prolific growth of conifers in the swamps

authigenic quartz in the upper freeport coal bed west central pennsylvania cathodoluminescence petrography was used to examine quartz grains contained in facies of the upper freeport coal bed middle pennsylvanian of west central pennsylvania samples included ash concentrates polished blocks of different lithotypes and standard petrographic pellets of specific gravity separates of facies channel samples more than 80 of the quartz in mineral and vitrain rich bands in the polished blocks of the upper freeport coal bed do not exhibit cathodoluminescence in specific gravity separates of the coal 100 of the quartz examined in the lightest gravity separates did not luminesce in the heaviest gravity separates which included shale parting material 60 of the quartz did not luminesce in contrast in a sample of shale directly overlying the coal bed more than 90 of the quartz luminesced on the basis of these cathodoluminescence data and other published data quartz in the upper freeport coal bed is interpreted to be authigenic in origin the authigenic quartz grains are postulated to have been derived from phytoclasts

fungal origin of oxidised plant material in the palangkaraya peat deposit kalimantan tengah indonesia implications for inertinite formation in coal abstract the top 1 0 1 5 m of the 6 m thick palangkaraya peat deposit in indonesia is decaying aerobically and contains up to 22 oxidised plant material i e inertinite in contrast intervals below the level of water table fluctuation contain less than 5 oxidised material analysis of fungal remains in the peat show there is a coincident increase in total aggregate hyphal length a measure of fungal activity with the proportion of oxidised plant constituents macroscopically the top of the peat which contains the greatest proportion of oxidised material is black lacks wood fragments and would be classed as a sapric or sapric hemic peat oxidised material in the peat is predominantly epidermal cell walls of primary roots these cell walls are abnormally thickened and display a distinctive dentate structure in cross section the texture of the cell walls are either laminated or granular and often contains intercellular nodules these features together with the absence of charcoal layers in the peat suggest that oxidised constituents were derived from fungal alteration furthermore the coincident increase in fungal hyphal length with the proportion of oxidised material may suggest a causal link based on texture morphology and size the same types of oxidised plant material found in the palangkaraya peat deposit have been identified in coal beds of tertiary age from indonesia new zealand and the u s a this indicates similar fungal alteration occurred in the past and may account for some of the oxidised constituents found in coal if the palangkaraya mire is used as a model fungal alteration zones may be recognised in coals as relatively thick 0 5 2 0 m laterally extensive macroscopically dull coal

botanical control on banding character in two new zealand coal beds abstract two new zealand coal beds were examined using a palaeobotanical approach to determine controls on banding characteristics the morley cretaceous coal is thickly 5 to 1 or 32 to 2 mm and well 25 banded whereas the brunner eocene coal is essentially non banded palynological analyses indicate that the morley was formed from a gymnosperm dominated vegetation with a secondary component of angiosperms in contrast the brunner was dominated by angiosperm vegetation with only a minor component of gymnosperms however it was found that any xylite vitrain bands 1 mm in either coal bed were comprised exclusively of secondary xylem of probable gymnosperm origin the presence of gymnosperm wood i e secondary xylem forming the larger bands in both coals can be related to the relative resistance of this material to chemical and physical decay as compared to all other plant tissues an absence of angiosperm wood in either the morley or brunner coal beds may be the result of the relative chemical degradability of angiosperm wood as compared to gymnosperm wood alternatively angiosperms in either of the two palaeo mires may have been shrubby and thus did not produce abundant woody tissue in either case the banded nature of the morley coal bed is the result of the presence of gymnosperm wood and the non banded nature of the brunner is the result of being dominated by a flora angiosperm which is easily degraded

petrographic characteristics and depositional conditions of permian coals of pench kanhan and tawa valley coalfields of satpura basin madhya pradesh india abstract this paper attempts to characterize the coals of satpura gondwana basin using a large number of pillar coal samples drawn from the working coal mines of pench kanhan and tawa pathakhera valley coalfields of this basin this westernmost gondwana basin of peninsular india is graben half graben type and occupies an area of 12 000 km2 with sedimentary fills 5000 m ranging in age from permian to cretaceous the barakar formation permian is exclusively coal bearing with a total coal reserve of nearly 2000 mt the results show that the coals of this basin are equally rich in inertinite 22 8 58 7 24 5 62 0 mmf basis and vitrinite 24 4 52 4 24 4 56 0 mmf basis the concentration of liptinite ranges from 8 8 to 23 2 9 0 26 0 mmf basis the dominant microlithotypes of these coals are inertite and vitrite with comparatively low concentrations of vitrinertite and clarite the vitrinite reflectance rom values suggests that the pench valley 0 30 0 58 coals are subbituminous c to high volatile c bituminous in rank while the kanhan and tawa valley coals 0 52 0 92 are subbituminous a to high volatile a bituminous in rank the localized enhancement of rank in the latter two basins has been attributed to the extraneous heat flow from deep seated igneous intrusions in the basin the microlithotype composition of these coals is suggestive of their evolution in limno telmatic zones under fluvio lacustrine control with the development of upper deltaic and lower deltaic conditions near the fresh water lacustrines the floral input is characteristic of forest swamps with intermittent floods leading to the development of reed moor and open moor facies particularly in the pench valley basin the gelification index gi and tissue preservation index tpi are suggestive of terrestrial origin with high tree density further moderately high gi and exceedingly high telovitrinite based tpi along with high ash content particularly for the coals of kanhan and tawa valley coalfields are indicative of the recurrence of drier conditions in the forested swamps furthermore lateral variation in tpi values is indicative of increase in the rate of subsidence vis a vis depth of the basin from east to west pench to tawa valley coalfield the ground water index gwi suggests that these coals have evolved in mires under ombotrophic to mesotrophic hydrological conditions the vegetation index vi values are indicative of the dominance of herbaceous plants in the formation of pench valley coals and comparatively better forest input in the formation of kanhan and tawa valley coals

algal bloom episodes and the formation of bituminite and micrinite in hydrocarbon source rocks evidence from the devonian and mississippian northern williston basin canada organic petrology incident light microscopy of middle devonian inter reef laminates and devonian mississippian epicontinental black shales williston basin canada indicates that algal bloom episodes and consequential bacterial activity played a significant role in the accumulation of amorphous bituminite iii rich organic microfacies corpohuminite like algal akinete cells produced by filamentous algae during algal bloom periods are persistent maceral inclusions within the potential hydrocarbon source rock intervals these cells ro mean range 0 24 0 90 are regarded as positive indicators of stressful palaeoenvironmental conditions unicellular tasmanites and leiosphaeridia marine alginite and variably degraded alginite remnants ghosts within the amorphous kerogen may be products of cell lysis photo oxidation and microbial alteration these processes are characteristic of algal bloom periods minute ca 1 m spheroidal and coccoidal bacteria like macerals are dispersed throughout the bituminite iii network attesting to the importance of microbial activity within the water column and sediment during and after organic matter accumulation dispersed granules laminations and replacement textures of micrinite like macerals within bituminite iii are interpreted as remnants of microbial alteration rather than a residual product of thermal maturation and hydrocarbon generation

the role of palynology in paleoecological analyses of tertiary coals abstract pollen spores and other plant microfossils are important constituents of tertiary coals both as petrographic components the maceral sporinite and as distinctive indicators of the nature of the depositional environment in which the coal forming peat accumulated palynological analyses which have been conducted on tertiary coals since the 1930 s play an increasingly important role in modern paleoecological analyses of coals among the most important factors controlling the petrographic composition and facies characteristics of coal deposits are the types and relative abundances of plants that composed the peat at present wetland environments in which peat accumulates mires range from marshes and bogs to forested swamps each is inhabited by distinctive plant communities these plant communities are associated with varied conditions of climate water depth chemistry and nutrient supply and the floras can be indicative of these conditions in the tertiary period plant communities of mires were also highly diverse and specialized especially as compared with those of the carboniferous the dominant species in some paleocene mire floras were gymnosperms but continuing a trend begun in late cretaceous time angiosperms became increasingly prominent through the tertiary the diverse angiosperm dominated mire floras produced coals that vary significantly in facies and hence in quality such contrasts are evident in contemporaneous coals from different paleolatitudes as well as among coals of different ages within the tertiary as exemplified by selected deposits in the western united states the palynofloras of these coals reflect the floristic composition of the plant communities of the ancient mires

the changuinola peat deposit of northwestern panama a tropical back barrier peat coal forming environment abstract a large 82 km 2 thick 8 m low ash low sulfur peat deposit has formed on the northwestern coast of panama its low ash and low sulfur contents can be attributed partly to 1 doming 2 the occurrence of a relatively continuous marine blocking beach barrier shoreline feature and 3 leaching of the mineral matter this deposit is roughly rectangular in shape and oriented with its longest axis parallel to the beach barrier shoreline it would produce an economic coal bed that is bright and finely banded in its thickest central region and more coarsely banded at its margins its northwestern margin would be characterized by interfingering of coal with sandstone and siltstone of the changuinola river flood plain whereas its southeastern boundary would be characterized by truncation of the upper part of the seam by marine to brackish shales siltstones and carbonates that were derived from almirante bay total sulfur was found to be very low less than 0 2 dry wt except in a few places in these rare cases nearly all of the sulfur was pyritic and the total sulfur content was anomalously high 14 although the general tendency was for total sulfur to increase wherever the deposit was influenced by marine conditions one case was found where sulfur was high at the base of an inland freshwater peat core which suggests either a hidden marine influence or the need for some new mechanism to explain sulfur enrichment in such an anomalous case differences in inherent fixed carbon contents and calorific values due to changes in peat type and analytical uncertainties tended to mask seamwide trends in these parameters however fixed carbon contents and calorific values showed a slight tendency to increase with depth especially if plotted for single peat types vitrinite reflectance within the hypothetical changuinola coal bed would be expected to increase as follows 1 toward the margins of the deposit 2 toward the bottom and top of the bed and 3 toward stream channels or tidal inlets

the petrographic composition of world coals statistical results obtained from a literature survey with reference to coal type maceral composition abstract this paper presents a statistical study concerning the petrographic composition of world coals in terms of vitrinite v liptinite l and inertinite i composition a comparison between vli compositions of coals from different ages facies continents and countries territories was done north atlantic palaeozoic coals show an average petrografic composition of vli 70 12 18 while gondwana palaeozoic coals show vli 52 8 40 mesozoic coals from north atlantic territories also show a higher v content 74 than gondwana coals of the same age 65 and a lower i content 18 than gondwana 21 north atlantic and gondwana tertiary coals have similar vli compositions 81 10 9 and 82 8 10 respectively data from quaternary coals are only available for north atlantic and these show a vli composition of 88 6 6 considering the ece un classification 1990 of coals into vitric liptic fusic trimaceric i and trimaceric l a study was carried out to determine the percentages of all coals falling into each of these categories the amount of vitric coals increases constantly from palaeozoic 54 5 to quaternary 98 6 with values of 68 4 and 90 2 for mesozoic and tertiary coals respectively on the opposite the amounts of fusic and trimaceric i coals decrease in the same way liptic and trimaceric l coals do not show a regular variation based upon the results an attempt is made to establish an alternative boundary limit for fusic coals i 55 to the one proposed by ece un i 50 a new proposal for a change of terminology is presented

in situ produced 10be measurements at great depths implications for production rates by fast muons in situ cosmogenic 10be values have been used to investigate a brazilian quartz vein from the surface to a depth of 15 m at depths greater than 1000 g cm2 deep enough for neutron induced reactions to be insignificant there is only a slight decrease in 10be concentration with increasing depth our results are consistent with deep production of 10be by a mechanism presumably induced by fast muons with an attenuation length of 5300 950 g cm2 and a contribution of 0 65 0 25 to the total surface production results are compared with values from the literature and implications of this re evaluation are discussed

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

peat forming materials and evolution of swamp sequences case analysis of a jurassic inland coal basin in china abstract a case analysis was conducted in the yima coal mine which is located in a jurassic inland basin located in the henan province of central china using data from palynological ecology plant residues coal petrography and some geochemical characteristics the plant community during this coal forming period and the precursors of the coal forming peat were determined the peat forming paleoenvironment and evolutionary sequences within the swamp were reconstructed according to the differences in the spore pollen complex of the coals in the yima mine seven kinds of palynofacies each characterized by predominant species occured within the relative beds seven different types of ecological characteristics are indicated the different stages are represented by the corresponding floral facies six diagnostic properties of the coal facies were determined by studying the petrographic characteristics of each coal and seven different kinds of ancient peat forming swamp paleoenvironments are indicated by the coal facies a genetic model of formation development and evolutionary sequences of the coal forming swamp in the jurassic of central china is proposed

the influence of depositional environments on coal petrographic composition of the lower kittaning seam western pennsylvania abstract lateral variations in maceral composition of the lower kittanning seam can be explained in terms of differential preservation of plant materials which is influenced by the ph eh of water within the peat swamp and by the rate of subsidence within the central part of the basin high telocollinite contents are observed this type of vitrinite represents large well preserved pieces of woody tissue whose preservation was favored by rapid burial towards the margins of the basin high desmocollinite contents are seen slower burial combined with the influx of neutral oxygenated fresh water permitted decomposition of the precursor materials producing this highly degraded type of vitrinite vertical variations in telocollinite and desmocollinite content can also be related to burial rates and ph eh conditions within the swamp throughout the basin high telocollinate contents observed in the lower part of the seam resulted from rapid burial under relatively low ph conditions continued high rates of subsidence led to an influx of neutral ph oxidizing waters associated with the encroaching marine environment under these new conditions more degradation of plant tissues occurred producing the high desmocollinite contents observed in the upper part of the seam this effect was most pronounced in the center of the basin an alternative explanation would be a change in vegetation type in response to the changing conditions the high desmocollinite content would then reflect a shift to a community dominated by smaller possibly herbaceous plants in addition to a change in vitrinite type towards the top of the seam a decrease in total vitrinite content and increases in total liptinite and inertinite contents are observed the increase in liptinite content is due to either 1 the higher resistance to decomposition of liptinite precursor materials when compared to vitrinite precursors in the more neutral conditions or 2 a change from a dominantly arborescent vegetation to a more herbaceous one the increase in inertinite results from an increase in transported material inertodetrinite and or an increase in the formation of inertinite macerals such as degrado fusinite possibly in response to the encroaching marine conditions an additional control on maceral composition is the level of metamorphism of the coal total liptinite content decreases towards the southeast in this area the coal has attained a sufficiently high rank that the reflectance of liptinite macerals approaches that of vitrinite thus making their identification difficult

maceral distributions in illinois coals and their paleoenvironmental implications abstract for purposes of assessing the maceral distribution of illinois u s a coals analyses were assembled for 326 face channel and drill core samples from 24 coal members of the pennsylvanian system the inertinite content of coals from the missourian and virgilian series averages 16 1 mineral free compared to 9 4 for older coals from the desmoinesian and older series this indicates there was generally a higher state of oxidation in the peat that formed the younger coals this state probably resulted from greater exposure of these peats to weathering as the climate became drier and the water table lower than was the case for the older coals although oxidation during allochthonous deposition of inertinite components is a genetic factor that needs further study to confirm the importance of the climate regional variation of the vitrinite inertinite ratio v i on a mineral and micrinite free basis was observed in the springfield no 5 and herrin no 6 coal members to be related to the geographical position of paleochannel river deposits known to have been contemporaneous with the peats that formed these two coal strata the v i ratio is highest generally 12 27 in samples from areas adjacent to the channels and lower 5 11 some 10 20 km away we interpret the v i ratio to be an inverse index of the degree of oxidation to which the original peat was exposed high v i ratio coal located near the channels probably formed under more anoxic conditions than did the lower v i ratio coal some distance away from the channels the low v i ratio coal probably formed in areas of the peat swamp where the watertable was generally lower than the channel areas

the nature and influence of fire in carboniferous ecosystems fusain occurs widely in carboniferous coals and sediments it is now recognised to represent charcoal and be the product of wildfire the occurrence of fire is partly constrained by atmospheric oxygen levels availability and nature of fuel and by aspects of climate rainfall and seasonability in particular the majority of fires in the carboniferous were probably started by lightning strikes or by volcanic activity experiments on the charring of modern plants has shown that the reflectance of charcoal and hence fusain is directly related to temperature of formation different fire types may yield fusain assemblages of differing reflectance spectrums but it may be significant that many modern charcoal assemblages yield only semifusinites as seen by reflectance microscopy the significance of these findings is assessed in relation to the use of fusinites and semifusinites as depositional indicators as interpreted from coal petrology fires may have a dramatic effect on ecosystems not only causing changes in vegetational succession but also severe erosion can occur following a major fire which can be traced in depositional systems in this paper we document three major carboniferous sedimentary systems affected by fire clastic sedimentary systems using extensive fusain deposits in mid lower carboniferous near shore sediments in donegal ireland volcanic systems using late early carboniferous volcaniclastic sequences in the midland valley of scotland and coal and coal bearing sequences in the upper carboniferous westphalian b of the pennine basin england in the later settings the influence of fire in peat formation and succession is assessed in addition data on the vegetational composition of charcoal assemblages is considered it is concluded that fire plays a major role in many carboniferous ecosystems

coalification trends in indian coals abstract a study of the coalification trends of indian coals covering a wide range of geological age permian eocene to pleistocene shows a progressive transition in physico chemical and optical properties from peat to semianthracite the relation between the maximum reflectance in oil of huminite vitrinite and volatile matter or fixed carbon has been found to be similar to that of the normally coalified british carboniferous coals also the coalification trend of indian coals measured in terms of elemental carbon and hydrogen appears to follow seyler s band and is similar to the normally coalified british carboniferous coals although coals of the two hemispheres follow the same normal coalification course their physical chemical and petrographical characters differ depending on the petrographic composition i e the macerals microlithotype and mineral matter contents the petrographic composition of a coal appears to be essentially controlled by the nature of the peat paleodepth paleotemperature and paleoheating in the coal basins

implications on the paleoecology of autochthonous lycopods in clastic sedimentary environments of the early pennsylvanian of alabama abstract numerous correlative localities throughout the upper cliff coal interval lower pennsylvanian blount county alabama have been observed in which lycopod forests are preserved these assemblages are present in lower delta plain facies interpreted to represent 1 the abandonment phase of a distributary channel system with resultant bayou development 2 non peat accumulating swamps capping interdistributary bay deposition 3 possible terminal phase of peat accumulating swamps and 4 crevasse splay deposits field observations in combination with sedimentological preservational and biological evidence support the conclusion that these autochthonous carboniferous lycopods represent a taphonomically biased assemblage of aquatic or semi aquatic swamp communities interpretations derived from the present study in conjunction with published accounts of erect lycopods suggest that these plants could tolerate all waters from fresh to saline conditions periodic drying of swampy habitats may have subjected lycopods to subaerial and aerial conditions but bulk replaced erect lycopods predominantly inhabited water stressed conditions the monotypic character of the lycopod forests supports the hypothesis that in the tropical lowlands of the tropical lowlands of the carboniferous lycopods held a relatively unique physiologically stressed position in the delta flood basin these arborescent lycopods became established in any depositional site subject to flooding and standing water when conditions prevailed which allowed for the establishment and development of individuals

dispersed angiosperm cuticles their history preparation and application to the rise of angiosperms in cretaceous and paleocene coals southern western interior of north america abstract cuticle the decay resistant outer layer of leaves and young stems provides a reliable means of identifying fossil plant remains and reflects the vegetative adaptations of plants to climate and other environmental parameters the study of dispersed angiosperm cuticles originated prior to world war ii and has focused on the origin and paleoecology of coal activity in dispersed cuticles reached a high point during the 1950s and 1960s with the study of tertiary lignites in central europe then subsided in central europe as workers from other regions expanded the technique to other time periods and geographic regions data from dispersed cuticles augment data from palynomorphs because dispersed cuticles originate from a different generation of the vascular plant life cycle and have different taphonomic histories because the analysis of dispersed angiosperm cuticles is unfamiliar to many geologists methods for the analysis and preparation of dispersed angiosperm cuticles are detailed in an appendix dispersed cuticle assemblages from coals in the upper albian longford member of the kiowa formation and the maastrichtian paleocene raton formation of the southern western interior provide new constraints on the times that angiosperms entered coal swamps and rose to dominance the kiowa assemblages indicate that angiosperms first entered coal swamp environments by the late albian while the raton assemblages indicate that angiosperms dominated primary productivity in some subtropical coal swamps by the late maastrichtian angiosperms in kiowa coals probably comprised pioneer species in conifer dominated vegetation the most common family of angiosperms was chloranthaceae angiosperms in upper maastrichtian raton coals comprised the dominant seed plants to the exclusion of conifers magnoliid dicots and monocots were the dominant taxa and comprised diverse genera and families evidence from palynology and types of preserved cuticle indicates that ferns were subordinate to seed plants in biomass in raton coals in contrast to some described assemblages from the northern western interior paleocene coals from the raton basin show the loss of many cretaceous angiosperm taxa as well as the appearance of new taxa including conifers belonging to taxodiaceae however these taxodiaceae were evergreen and subordinate in abundance to angiosperms vegetational patterns shown by cretaceous paleocene coals of the southern western interior contrast with those of more northerly regions and indicate a poleward gradient in the timing of angiosperm dominance in coal swamps

coal facies interpretations based on lithotype and maceral variations in lower cretaceous gates formation coals of western canada abstract maceral analyses of lithotype samples from lower cretaceous coal seams have been used to define compositional characteristics of the various lithotypes and to assess coal facies changes within the seams based on maceral and lithotype variations the mean petrographic compositions of the lithotypes show a general trend to decreasing vitrinite increasing inertinite and increasing mineral matter contents from the bright to dull varieties the bright lithotypes are considered to have been formed in wet and densely forested swamps whereas the banded lithotypes were formed under somewhat drier conditions within the dull lithotype two distinct types were recognized based on differences in petrographic composition and the occurrence or absence of facies diagnostic macerals it is suggested that these differences are due to formation in distinct mire facies under the influence of open moor or raised mire conditions the lithotype variations within the seams together with the data on their petrographic composition were used to define facies changes which occurred during accumulation of the peats three types of seam development are recognized a seams containing a high proportion of clastic beds indicative of frequent floodings of the swamps these seams are characterized by the dominance of oscillatory sequences of bright lithotypes and dulling upward sequences below clastic beds the brighter lithotypes were formed in forested swamps and fens whereas for the duller sequences influences of open moor conditions are indicated b seams containing only minor thin clastic beds indicating relative stability of water levels during formation of the peat these seams are characterized by the predominance of duller lithotypes with common repetitions of dulling upward sequences the dulling up sequences indicate transitions from wet and very wet forest swamps to drier conditions with lower tree density c transitional seams characterized by a few clastic beds these seams formed under intermediate conditions of stability in respect to flooding events the seams are characterized by the predominance of banded lithotypes dull lithotypes near partings and brightening and dulling up sequences the brightening up sequences represent transitions from dry forest swamp to wet and very wet forest swamps while a reverse trend is indicated for the dulling up sequences the overall petrographic characteristics of full seam sections indicate that the seams are in general relatively low in vitrinite and relatively rich in inertinite macerals liptinite content is negligible and mineral matter contents are low based on petrographic indices obtained from facies diagnostic macerals an accumulation of the ancient peats under prevailing wet to very wet forest swamps is suggested vicinity to more open moor conditions is indicated for one seam by the higher input of dispersed macerals