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

biological markers in lower jurassic synrift lacustrine black shales hartford basin connecticut u s a abstract the east berlin formation lower jurassic hartford basin connecticut u s a is distinctive for its six cyclic units of lacustrine black shale and gray mudstone separated by playa and fluvial redbeds the black shales are each about a meter thick and were deposited in subtropical thermally strastified oligomictic lakes the youngest of which lakes 3 through 6 were large enough to flood most of the basin and attained depths of several tens of meters the saturate fractions of solvent extracts of organic rich black shales from each of the six lakes collected at fresh roadcuts near east berlin are dominated by extended homologous series of n alkanes alkylcyclohexanes and branched chain alkanes a striking feature of the black shales is the presence of a series of extended tricyclic terpanes from c20 to at least c41 hopanes are either not detectable or present only in subordinate quantities relative to the tricyclic terpanes the samples are depleted in hopanes in part because of the elevated maturity level mid to late oil window tricyclic terpane concentrations may also have been enhanced by fractionation effects related to oil expulsion out of the black shales in addition the original organic matter may have been exceptionally rich in tricyclic terpane precursors i e fossil lipids of prokaryotes present in anoxic moderately saline alkaline lakes

observations on fluorinite and fluorescent vitrinite with the transmission electron microscope abstract transmission electron microscopy tem has been used to study fluorinite occurrences in four coals ranging in rank from soft brown coal to high volatile bituminous the fluorinite has a substructure of lipoid rich lamellar and nodular units about 0 1 0 5 m across these components together with enclosing humic matter and in some cases thin cuticle appear to derive from leaves or leaf like material from vascular plants fluorescent vitrinite in one of the coal samples of bituminous rank was also studied with tem this fluorescence is attributable to exsudatinite like inclusions of petroleum origin within the humic matter of the vitrinite

evidence of early generation of liquid hydrocarbon from suberinite as visible under the microscope the early generation of liquid hydrocarbons from suberinite can be clearly observed under the microscope the generation of this oil like material mainly in the form of exsudatinite from the maceral suberinite occurs at a maturity level of about 0 4 vitrinite reflectance hydrocarbons appear to be naturally expelled from coal initially through sweating and agglomeration of suberinite which subsequently forms exsudatinite it is suggested that extensive expulsion of exsudatinite causes cracks to develop in vitrinite whereas limited expulsion of exsudatinite will only impregnate the vitrinite matrix if cracks are formed it is possible they could progressively develop to form an exsudatinite crack network the formation of such a network is believed to represent an effective way of hydrocarbon expulsion from coal source rocks

variation in the chemistry of macerals in coals of the mist mountain formation elk valley coalfield british columbia canada abstract variations in elemental and molecular chemistry of macerals with vitrinite semifusinite and sporinite in particular are discussed for the coal seams of the mist mountain formation in the elk valley coalfield in western canada in the south elk valley coalfield carbon content of vitrinite oscillates around 85 and oxygen content increases gradually up section from seam a to c in the north elk valley coalfield carbon content in vitrinite shows marked variations from 70 to 85 between the samples and is lower than in the south elk valley coalfield which is consistent with a higher maturation level of south elk valley coalfield samples sulphur content is below 1 in both coalfields semifusinite in general has higher carbon and lower oxygen content than vitrinite whereas cutinite has higher carbon content than vitrinite and slightly higher or comparable to that of semifusinite functional group distributions show large variations between the seams and these variations are attributed mainly to differences in a primary depositional environment and only occasionally to later weathering and oxidation processes the results presented in this paper provide also information on the length and branching of aliphatic chains which for liptinite macerals is valuable from the oil generation viewpoint whereas for semifusinite it may help to understand reactive versus non reactive behaviour during coking

a revised relaxation time spectrum for fennoscandia summary the fennoscandian relaxation time spectrum rts first derived by mcconnell 1968 is a classic data set in studies of glacial isostatic adjustment gia we outline a new method for estimating an rts from a set of strandline data which is based on a damped least squares solution for spherical harmonic coefficients associated with the strandline heights in contrast to the hankel transform approach outlined by mcconnell 1968 the method does not require interpolation or extrapolation of the data nor does it use the assumption that peripheral deformations are zero we begin by applying the new approach to a suite of synthetic strandlines these synthetic calculations quantify the effect on the rts estimates of the common assumptions of free decay uplift an axisymmetric fennoscandian deformation field and the uncertainty introduced by limited spatial and temporal sampling of this field recently the accuracy of the sauramo 1958 strandline data upon which the mcconnell 1968 rts was based has been questioned wolf 1996 accordingly we apply our new approach to a set of more robust strandline data published by donner 1964 1969 1980 1995 to compute a revised rts for fennoscandia at high harmonic degrees above 50 our new rts is characterized by weak constraints whereas mcconnell s 1968 rts suggests a significant reduction in relaxation times relative to the values at low degrees this reduction was the basis for mcconnell s 1968 inference of an elastic lithosphere in contrast to this we conclude that the trend is an artefact of the observational data set he adopted at lower degrees mcconnell s 1968 relaxation time estimates lie at the lower end of the range implied by the present analysis to complete our study we apply the techniques of linearized bayesian inference to invert our newly derived rts for mantle viscosity we find that the rts provides an estimate of 5 1020 pa s for the volumetric mean viscosity in a region extending from the base of the lithosphere to about 550 km depth target regions which extend from the transition zone to 1200 km depth are less well constrained however the average viscosity from the base of the lithosphere to 1200 km depth is consistent with the classic haskell 1935 value of 1021 pa s for mantle viscosity finally we demonstrate that viscosity models within the class inferred by mitrovica forte 1997 from joint inversions of postglacial relaxation times associated with gia and mantle convection observables simultaneously fit the revised fennoscandian rts

palaeogene lacustrine record in mallorca nw mediterranean spain depositional palaeogeographic and palaeoclimatic implications for the ancient southeastern iberian margin abstract middle bartonian middl1e eocene and chattian upper oligocene lacustrine and alluvial lacustrine successions exist in mallorca northwestern mediterranean they yield a significant palaeobiological record comprising fossil land plants and vertebrates and constitute the best available depositional record for a preliminary palaeogeographic and palaeoclimatic analysis of the northeastern part of the palaeogene southern iberian margin western tethys both lacustrine systems developed under similar warm and humid climatic conditions increasingly affected by seasonal and or pluriannual rhythms marked by changing precipitation patterns these climatic conditions were mainly caused by the low palaeolatitude where the lacustrine systems evolved the still probable although decreasing influence of indo pacific warm surface currents and the occurrence of very extensive marine water masses adjacent to wide emerged continental zones the palaeogene lacustrine systems were shallow and characterised by low gradient depositional conditions they were perennial open freshwater oligosaline carbonate lakes where eutrophy thermal meromixis and anoxic bottom conditions could develop allowing the accumulation and preservation of macrophytic plant remains of the circum lacustrine marginal belt and neighbouring terrestrial mesophytic zones the higher plant algal bacterial organic contribution balance favoured the generation of mineable huminitic coal seams carbominerites and of gas prone kerogene type iii and iib source rocks the hydrogen bicarbonate rich waters led to high biogenic and inorganic bio induced carbonate sediment production biogenic muds cyanobacterial incrustations and travertine and tufa precipitation constituted the major carbonate products moreover the high ph conditions in the lacustrine water bodies and in the lacustrine sediment pore waters favoured bacterial sulphate reduction contributing to organic sulphur enrichment in coals these highly alkaline conditions also resulted in some cases in the exceptionally good preservation of chlorophyllinite a rare liptinite maceral recorded in the eocene coal deposits the middle eocene lacustrine system did not evolve in a very well defined tectonic setting characterised by the generation of low uplifts and gently subsiding basins terrigenous contributions from the source areas and clastic sedimentation were restricted to river mouths high autochthonous carbonate production and accumulation characterised most of the remaining lacustrine zones a significant spring recharge of the lacustrine zones is suggested by the well developed spring related travertine deposits by contrast the oligocene lacustrine zones developed both in fluvial related floodplains and in the distal zones of a major alluvial system which was fed from tectonically active source areas located to the nw of the island a more significant water runoff contribution is suggested for this system although underground recharge could also be substantial

detection and evaluation of hydrocarbons in source rocks by fluorescence microscopy abstract in pursuing the detection of hydrocarbons in sedimentary rocks by conventional petrological methods an attempt has been made to correlate standard fluorescence parameters with the quality and quantity of hydrocarbons present in crushed rocks embedded in epoxy resin the capacity of the embedding resin commonly used in the preparation of petrographic samples to extract and physically fix hydrocarbons is recognized this phenomenon permits one to measure monochromatic fluorescence parameters i 546 and q u v 650 500 on the trapped hydrocarbons and to correlate these parameters with selected geochemical data the potential application of using these petrological parameters to evaluate oil quantities and qualities is tested using real case studies it is also shown that it is possible to directly detect the mature zone in each case

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

the petrology of greek brown coals abstract results are given in the petrography of greek coals collected from most of the major coal bearing basins in greece rank was determined by measuring reflectances on the maceral varieties eu ulminite a and eu ulminite b and on the maceral textinite reflectances obtained from these components indicate a coalification stage of brown coal for all samples within this group of samples there is however a fairly wide scatter of reflectance values indicating for some of them the transition zone from peat to brown coal and for others a coalification stage close to the transition into bituminous coals reflectances obtained from eu ulminite a and eu ulminite b were found to correlate well with chemical rank parameters such as volatile matter and calorific value composition was determined by maceral analysis the coals are in general characterized by low amounts of macerals of the inertinite group low to intermediate amounts of macerals of the liptinite group and high amounts of macerals of the huminite group within the latter group densinite attrinite eu ulminite and textinite make up the bulk of the samples typical macerals observed in the coals are illustrated by two black and white and three colour plates cluster analysis based on maceral distribution mineral matter and reflectance indicates that the samples studied can be divided into three major groups the first one is dominated by eu ulminite and densinite with relatively high reflectances the second is dominated by attrinite textinite and texto ulminite with somewhat lower reflectances the third is represented by a single sample in which textinite and resinite are the most abundant macerals this sample also has the lowest reflectance

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

regional patterns of reflectance in lignites of the ravenscrag formation saskatchewan canada abstract random reflectances in oil r om were measured on lignite samples from 60 boreholes in southern saskatchewan covering an area from the cypress hills to estevan measurements were made on three macerals of the huminite group namely eu ulminites a and b and corpohuminite the study showed these results 1 1 reflectance values on eu ulminite a vary from 0 18 to 0 42 the range in eu ulminite b is from 0 28 to 0 46 and in corpohuminite from 0 33 to 0 48 2 2 along a west to east section line a subtle but consistent eastward increase in reflectance was observed from wood mountain to estevan 3 3 of the three macerals studied eu ulminite a seemed to be most sensitive to change and to show the most uniform behaviour along the west to east section line 4 4 rank variations appear to be related to present day heat flow patterns determined by geothermic studies areas of low geothermal gradients coincide with areas of lower reflectances in the ravenscrag coals while higher reflecting coals are associated with areas of higher geothermal gradients

investigations on the petroleum generation potential of bituminous coals from the saar region abstract the saar basin contains bituminous coals high volatile a and b five coals of westphalian and stephanian age with distinctly varying maceral compositions were analysed by soxhlet extraction and supercritical extraction with different solvents and microscopically from the data obtained it is concluded that the oldest coals have a potential for oil generation whereas the younger coals do not this conclusion is explained by varying liptinite contents and varying adsorption capacities of different vitrinite macerals for bitumen

a geochemical study of macerals from a miocene lignite and an eocene bituminous coal indonesia optical and chemical studies of maceral concentrates from a miocene lignite and an eocene high volatile bituminous c coal from southeastern kalimantan indonesia were undertaken using pyrolysis optical electron microprobe and ftir techniques pyrolysis products of vitrinite from bituminous coal were dominated by straight chain aliphatics and phenols the huminite of the miocene lignite produced mostly phenolic compounds upon pyrolysis differences in the pyrolysis products between the huminite and vitrinite samples reflect both maturation related and paleobotanical differences an undefined aliphatic source and or bacterial biomass were the likely contributors of n alkyl moieties to the vitrinite the resinite fraction in the lignite yielded dammar derived pyrolysis products as well as aliphatics and phenols as the products of admixed huminite and other liptinites the optically defined resinite rich fraction of the bituminous coal from kalimantan produced abundant n aliphatic moieties upon pyrolysis but only two major resin markers cadalene and 1 6 dimethylnaphthalene this phenomenon is likely due to the fact that eocene resins were not dammar related data from the electron microprobe and fourier transform infrared spectrometry strongly support the results obtained by py gc ms and microscopy

effects of slab mineralogy on subduction rates although velocities of subducting slabs should be controlled primarily by their negative thermal buoyan cies their mineralogy can also have signicant eects we explore this by using thermo kinetic modeling to predict mineralogy and compare the resultant buoyant driving force to the opposing viscous drag phase transitions of mg fe 2sio4 in subducting slabs depend on thermal struc ture in two ways first equilibrium phase boundaries should be deflected causing local buoyancy anomalies whose sign depends upon that of the clapeyron slope as slabs rst enter the transition zone negative anomalies should acceler ate them but positive anomalies that arise when they fully penetrate the transition zone should slow them such ef fects may induce geologically abrupt changes in plate mo tions second olivine that persists metastably in slabs will form regions of positive buoyancy which should reduce slab velocities the coldest and fastest slabs should be slowed more greatly thus narrowing the range of feasible subduc tion rates decreased descent rates however allow slabs to warm and metastable wedges to thermally erode such neg ative feedback mechanisms may serve to regulate subduction rates

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

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

characterization of the source rocks of a paleo petroleum system cameros basin based on organic matter petrology and geochemical analyses abstract the cameros basin is a paleo petroleum system formed in the north eastern iberian peninsula the basin formed during the mesozoic iberian rift and was later inverted during the alpine orogeny hydrothermal events took place during the post extensional and inversion stages producing an important impact on the thermal history of the basin in order to determine the source rock of the petroleum system of the basin organic matter characteristics the petroleum generation potential and the maturity of the basin infill are determined by means of petrology and geochemical analyses several organic rich units of the stratigraphic record of the basin are potential source rocks for hydrocarbons generation although their characteristics differ depending on their location organic matter content in the northern sector is scarce and limited to vitrinite inertinite and solid bitumen particles the residual total organic carbon toc the different evolution of the source rocks in the basin is the result of the combination of differential subsidence rates which determine different thermal histories and of the circulation of hydrothermal fluids in the northern central sector during the evolution of the basin

novel development in fluorescence microscopy of complex organic mixtures application in petroleum geochemistry abstract new data on the spectral fluorescence properties of complex organic mixtures derived from organic rich sediments and from fossil fuels are presented both the spectral ranges of the bitumen fractions including extractable hydrocarbons and polar compounds and the factors governing the spectral characteristics of complex organic mixtures are established the data provide rapid means of determining qualitatively an abundance or low concentration of saturates of highly alkylated aromatics and of condensed aromatic systems in such entities as extractable organic matter kerogen migrated hydrocarbons and liptinite macerals the implication of the data to petroleum geochemistry is discussed

characteristics of upper cretaceous coals from enugu nigeria related to bitumen generation and mobilization abstract a set of nine upper cretaceous coals of sub bituminous rank were studied petrographically and geochemically the coals contain considerable amounts of various liptinites as well as fluorescent vitrinite some bitumen has been generated and mobilized in these low rank coals as evident by the presence of exsudatinite nevertheless no hydrocarbons have been expelled as the amount of bitumen generated is not considered to be sufficient to overcome the threshold saturation of the coals

deposition floral composition and sequence stratigraphy of uppermost triassic rhaetian coastal coals southern sweden abstract two uppermost triassic rhaetian coal beds a and b bed bjuv member southern sweden deposited at the margin of the danish basin were investigated in order to interpret the peat forming environments in a sequence stratigraphic context and to establish the peat forming vegetations of the precursor mires peat formed close to the coastline and was governed by base level watertable rise linked to relative sea level rise which is emphasized by rare occurrences of marine phytoplankton micrhystridium lunnomidinium scaniense and rhaetogonyaulax rhaetica in the b bed a maximum flooding surface mfs7 between the coal beds a and b shows that peat accumulation occurred as a coastal response to the continued transgression of the danish basin that culminated with deposition of the coal bearing bjuv member the lower b bed accumulated in a transgressive systems tract tst and the upper a bed in a highstand systems tract hst the b bed consists of coal and coaly mudstone intervals showing that peat formation repeatedly was outpaced by relative watertable rise the huminite rich coal intervals indicate peat formation under oxygen deficient stagnant water conditions where the peat accumulation rate balanced the watertable rise overall low ts values indicate a freshwater mire the base of coal bed b marks the start of a relative decrease in creation of accommodation space and the surface between the sediments and coal bed b represents a terrestrialisation surface tes the palynofloral composition suggests that the initial mire was characterised by dipterid dicksoniacean tree ferns and marattialean ground ferns and few canopy trees dominated by cupressacean taxodiacean wet loving conifers with subordinate bennettitalean and caytonialean trees the coal intervals in the b bed represent terrestrialisation situations characterised by a reduced ratio of accommodation rate peat accumulation rate the palynology of these intervals indicates establishment of canopy trees primarily cupressacean taxodiacean conifers accompanied by bennettitaleans and caytonialeans with an understory of marattialean ground ferns and rarer tree ferns flooding surfaces fs and accommodation reversal surfaces ars in the b bed reflect changes in the rate of watertable rise the coaly mudstone intervals represent paludification situations with an upward increasing ratio of accommodation rate peat accumulation rate in general the palynology of the b bed suggests a coal floral composition that was dominated by mid and upper canopy plants consisting of cupcressaceaen taxodiaceaen trees probably occupying areas with standing water while ginkgos cycads bennettiales and caytoniales and other seed ferns grew in less wet areas understory plants were less abundant whereas a ground cover of ferns mainly of the families marattiales and osmundales as well as lycophytes may have been pronounced the upper surface of the b bed is a give up transgressive surface guts above which peat accumulation was replaced by siliciclastic deposition the palynofloral composition suggests an open mire dominated by ground ferns and probable tree ferns with minor bennettitalean and caytonialean mid canopy trees and with hardly any upper canopy trees the a bed is considerably richer in inertinite compared to the b bed the palynofloral and petrographic change correlates with an increase in fire activity across the triassic jurassic boundary and deforestation of the early jurassic mires

the geology and coal petrology of a miocene lignite profile at meliadi mine katerini greece abstract the present study describes vertical variations in petrographic composition of a miocene lignitebearing succession from the moschopotamus basin greece the lignite beds are described megascopically in terms of lithotypes and microscopically by maceral contents examination of lithotype variations within the seams and the distribution of facies critical macerals such as humotelinite and humodetrinite and the relatively low inertinite contents suggest a formation of the miocene lignites as reed marsh to wet forest type swamps in a lower delta plain depositional setting reflectances measured on the maceral type eu ulminite b range from 0 36 to 0 42 r random placing the meliadi coals into a transition zone from lignite to subbituminous coal

striking liptinitic bark remains peculiar to some late permian chinese coals abstract an unusual liptinite coal component has been reported in the chinese literature over the past sixty years it has been described as a maceral in the chinese national standard 1991 but it has not been named internationally in chinese literature it is called barkinite on the basis of its morphological features and because it is believed to have originated as bark tissue barkinite occurs in late permian marine influenced coals and is best represented in the changguang leping and shuicheng basins of southern china the material originates from plant periderm or the bark of higher plants however bark contains a variety of substances including resin and suberin which are recognised as the precursors of the resinite and suberinite macerals barkinite is distinguished by i its thickness individual pieces can be more than ten cells thick and several centimetres long and ii it fluoresces strongly at 0 6 vitrinite reflectance and loses its fluorescence at about 1 1 vitrinite reflectance the reporting of barkinite from only chinese coals may be due to its origin from lepidodendron and psaronius flora which was common in the northern hemisphere during the carboniferous but which was isolated to china by the late permian it is proposed that the remnant flora evolved into unique forms in china by the late permian lepidodendron and psaronius remains coupled with a strongly marine influenced peat forming environment have given rise to barkinite and to its restricted distribution

geological controls on the coal quality of the mequinenza subbituminous coal deposit northeast spain abstract the results of geological petrographical geochemical and mineralogical studies performed to determine the coal forming paleo environmental conditions which gave rise to anomalous enrichments in organic sulphur molybdenum and uranium in the oligocene mequinenza subbituminous coal deposit of northeastern spain are summarized this paper demonstrates the major influence exerted by the paleohydrology of the depositional framework on the early diagenetic evolution of the precursor peat deposits the s mo and u enrichments the preservation of aragonite and chlorophillinite and the high degree of gelification of the mequinenza coal are a consequence of alkaline syngenetic conditions in the depositional environment similar conditions can be inferred for many mesozoic and tertiary coal deposits in the mediterranean region mallorca sardinia hungary bulgaria serbia greece and turkey however the source of sulphur may have been different and have included triassic and early jurassic sulphate recycling scenarios or volcanic sources whatever the source sulphur enrichment is always influenced by the alkaline depositional environments developed in basins generated during the alpine cycle in circum mediterranean mobile belts

petrographic and chemical properties of carboniferous resinite from the herrin no 6 coal seam abstract resinite is a naturally occurring substance found in coal and derived from original plant resins it is ubiquitous in north american coals and comprises 1 to 4 by volume of most illinois coals it has been commercially exploited in the western usa for use in adhesives varnishes and thermal setting inks the major objectives of this study were 1 to separate resinite macerals from the herrin no 6 coal seam and to carefully verify by petrographic and fluorescence microspectrophotometric methods that the separated material was indeed resinite 2 to characterize the chemical composition of the separated resinite by py gc ms techniques and 3 to confirm the earlier results that show that this carboniferous resinite was a much different chemical substance than the cretaceous and younger resinites an additional objective was to compare the separated resinite to the resinite being commercially exploited in the western usa high purity fractions of resinite concentrates were separated from the herrin no 6 coal by a combination of density gradient separation and sink float techniques the chemical structure of the resinite concentrate indicated by the py gc ms analysis is that of a straight chain aliphatic polymer much like common polyethylene this result confirms the earlier work of nip et al nip m de leeuw j w crelling j c 1992 chemical structure of bituminous coal and its constituent maceral fractions as revealed by flash pyrolysis energy fuels 6 125 136 the assumption that the resinites in the illinois basin were similar in nature to the commercial resinites of the younger coals of the western usa appears invalid in the case of the resinite in the herrin no 6 coal although the botanical function of the carboniferous resinite is at present unclear it is clear that the cutinite and resinite precursors had not yet evolved to the point where they had differentiated into significantly different chemical compounds

oil prone alginite macerals from organic rich mesozoic and palaeozoic strata saskatchewan canada abstract hydrogen rich oil prone remnants of algae or alginite macerals are examined from organic rich carbonate and siliciclastic phanerozoic intervals at saskatchewan canada using incident light fluorescence microscopy upper cambrian alginites from siliciclastic rocks contribute to types ii iii kerogen as defined by rock eval pyrolysis and consist mainly of unicellular prasinophyte leiosphaeridia unique agglomerations of synsphaeridium sphaeromorphs and two types of coccoidal gloeocapsomorpha alginite middle ordovician platform to basin shales host mainly disseminated gloeocapsomorpha prisca alginite macerals types i ii kerogen upper ordovician platformal carbonates contain disseminated and stromatolitic varieties of g prisca alginite type i kerogen with the latter occasionally forming wholly organic well preserved microtextures concentrations of nostocaceae like filamentous alginite type ii kerogen occur locally in upper ordovician carbonates and form unique brecciated and crinkled stromatolites middle devonian type ii kerogen rich intervals from a platform setting are dominated by stromatolitic nodularia like filamentous alginite whereas abundant leiosphaeridia and tasmanites alginite characterize inter reef basinal palaeoenvironments middle and upper devonian organic rich intervals associated with evaporites contain mainly stromatolitic filamentous alginite with only minor amounts of prasinophyte alginite black shales of devonian mississippian age contain abundant leiosphaeridia and tasmanites alginites within a type ii amorphous kerogen network the smallest leiosphaeridia occur in inner shelf rocks whereas the largest forms characterize outer shelf to basin devonian mississippian shales mesozoic marine marls and shales contain prasinophyte alginite dominated by small unnamed sphaeromorphs leiosphaeridia tasmanites and minor pterosphaeridia types ii iii kerogen fresh to brackish water colonial botryococcus alginite as part of a type ii kerogen occurs initially in mesozoic strata deposited in nearshore palaeoenvironments

the coal bearing cenozoic as pontes basin northwestern spain geological influence on coal characteristics lignite deposits in the cenozoic as pontes strike slip basin northwestern spain were formed as a function of specific paleoclimatic conditions and tectonic evolution of the basin during the early evolutionary stages the presence of active normal faults and thrusts inside the basin resulted in two subbasins with distinct differences in sedimentary records with respect to lignite seam occurrence thickness area1 extent and lithotype development in contrast during the late evolutionary stages the basin was not split and a more homogeneous sedimentary record in terms of coal seam occurrence and lithotype characteristics developed a total of 26 lignite samples distributed along the basin infill were analyzed by organic petrography and geochemistry all are lignite b astm the lignites deposited during lower basin infill sedimentation units 1 and 2 are dark matrix rich mainly huminitic brown coals with minor bright liptinitic rich coal lithotypes the dark huminitic coals in these units show sedimentological and paleontological evidence of lacustrine influence persistent relatively moderate to low tissue preservation index tpi values and high average gelification index gi values are characteristic of these limno telmatic coals lignites in the upper basin infill unit 4 are almost exclusively matrix rich huminitic brown coals persistent widespread low tpi values and variable but low average gi values are also characteristic of these telmatic coals the overall coal petrological data trend tpi gi and widespread development or absence of liptiniteenriched lignite layers recorded from the lower to the upper basin infill units agrees with the stratigraphic and sedimentological data which show a trend of increasingly drier conditions development of bright liptinite enriched lignite layers was widespread during the early basin evolutionary stages and was influenced by punctuated water table oscillations sedimentological petrological and organic geochemical data point to the conclusion that although the paleoenvironments where peat deposition took place did not undergo dramatic changes they were affected by distinguishable

the importance of thermal behaviour and petrographic composition for understanding the characteristics of a portuguese perhydrous jurassic coal abstract the perhydrous batalha coal portugal is found in the cabacos and montejunto formation of the oxfordian kimeridgian upper jurassic age from the macroscopic point of view its appearance is similar to other perhydrous coals microscopically the maceral group of huminite is the main organic component 96 ulminite being the most important petrographic component followed by textinite with resinite 4 lumina filled the huminite random reflectance is 0 33 this coal is characterized by high h c atomic ratio and anomalous physical and chemical properties that are characteristic of perhydrous coals such as i the absence of any correlation between reflectance and the chemical rank parameters ii a lower real density than that of non perhydrous coals iii a high hydrogen content and iv suppressed reflectance using its calorific value moist ash free basis as rank parameter batalha coal must be considered a subbituminous a coal hydrogen enrichment due to the presence of resinite has influenced the technological properties of this coal namely i reduction of the thermostability and decrease in the temperature of initial thermal decomposition due to among other reasons the existence of aliphatic structures with low dissociation energy bonds resulting from the presence of resinite ii from the dtg profile the volatile matter combustion and char combustion is not evident iii development of chars made up of isotropic particles with angular edges which is typical of a low rank coal iv the evolution trend of gaseous compounds co co 2 and ch 4 during pyrolysis and v an increase in its calorific value due to its hydrogen content the study of this coal which is interbedded in jurassic formations in the lusitanian basin of portugal is a new contribution to the assessment of the evolution of organic matter in this area

classification of oil shales coals and other organic rich rocks abstract oil shales are a complex group of rocks which were deposited in a wide range of sedimentary environments and have a wide range of largely alginite dominated maceral assemblages a system of classifying oil shales and sapropelic coals is based on relative abundances of macerals classification of oil shales has applications to the commercial development of oil shale deposits and to the classification of petroleum source rocks

fluorescence properties of palaeozoic oil prone alginite in relation to hydrocarbon generation williston basin saskatchewan canada abstract alginite macerals the oil prone microscopic components of hydrocarbon source rocks fluoresce in the visible region when irradiated with ultraviolet light the fluorescence properties max and red green quotient of coccoidal unicellular and filamentous alginite macerals were investigated in palaeozoic potential hydrocarbon source rocks northern williston basin saskatchewan canada this study documents the variation in fluorescence properties of alginite during thermal maturation and the onset of petroleum generation values of max nm of disseminated coccoidal gloeocapsomorpha alginite from upper cambrian siliciclastics and upper ordovician carbonates show different magnitudes of red shift with increasing thermal maturity gloeocapsomorpha prisca disseminated alginite and g prisca stromatolitic alginite from upper ordovician kukersites exhibit unique fluorescence properties with increasing thermal maturity the former undergoes a greater red shift in fluorescence than the latter over an 1800 m change in depth of burial devonian and mississippian unicellular prasinophyte leiosphaeridia and tasmanites alginite show a minimal change in fluorescence properties max 450 500 nm between vitrinite reflectance values of 0 35 and 0 65 ro beyond 0 65 ro vitrinite reflectance prasinophyte alginites show a marked red shift to a max of 560 600 nm this phenomenon is coincident with peak hydrocarbon generation from a type ii filamentous alginite bituminite kerogen within middle devonian carbonate source rocks a comparison of the fluorescence properties of palaeozoic prasinophytes with the fluorescence properties of mesozoic prasinophytes reveals that the latter undergo a substantially greater red shift in max with increasing thermal maturity relative to the former this conspicuous difference is interpreted as a reflection of the well documented distinct difference in species and abundance of leiosphaeridia and tasmanites alginite between the geological eras

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