observations of turbulence in stratified flow abstract various theoretical properties of the structure function are evaluated additional functions are constructed to describe the overall influence of stratification the anisotropy and intermittency of the turbulence and the asymmetry of the main drafts these functions and the usual spectral decomposition are computed from aircraft measured turbulence data collected in nocturnal boundary layers and in turbulence over mountainous terrain certain features of the turbulence are found to depend more on stability than on the external situation three general types of turbulence are found 1 intermittent turbulence driven by shear driven overturning 2 continuous turbulence where strong drafts in the presence of shear are characterized by sharp boundaries or microfronts particularly on their upstream sides and 3 weaker continuous turbulence the costructure fields are generally consistent with vertical gradient transfer however the bora turbulence on larger scales is dominated by horizontal motio

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

geochemical and petrographic evidence for the co occurrence of races b and l of botryococcus braunii in the maoming oil shales china abstract around 30 maoming oil shale samples were collected and analyzed geochemically to investigate their biomarker compositions c31 and c33 botryococcanes were abundant in some samples whilst high contents of lycopanes c39 and c40 and a monoaromatic lycopane derivative with concomitant occurrence of botryococcanes were also detected in other samples these indicate that the fossils of the races b and l of botryococcus braunii co exist in the maoming sediments thus providing an excellent opportunity to explore the morphological differences of two races of b braunii different preparation and observation methods were carried out for better and detailed morphological observations enabling the fossil characters between race b and l of b braunii to be recognized better observations were obtained using white fluorescence transmitted light under uv induced fluorescence microscopy because yellow fluorescence was avoided race b of b braunii has polygonal cup mouths and is often covered by an envelope however race l has a relatively smaller colony size and round cup mouth the co occurrence of race b and l of b braunii in maoming sediments possibly implies a tropical to subtropical climate during the late eocene oligocene period in the study area

migrating and nonmigrating semidiurnal tides in the upper atmosphere excited by tropospheric latent heat release migrating and nonmigrating semidiurnal tides

ionospheric electron density inversion for global navigation satellite systems radio occultation using aided abel inversions the abel inversion of ionospheric electron density profiles with the assumption of spherical symmetry applied for radio occultation soundings could introduce a greater systematic error or sometimes artifacts if the occultation rays trespass regions with larger horizontal gradients in electron density the aided abel inversions have been proposed by considering the asymmetry ratio derived from ionospheric total electron content tec or peak density nmf2 of reconstructed observation maps since knowledge of the horizontal asymmetry in ambient ionospheric density could mitigate the inversion error here we propose a new aided abel inversion using three dimensional time dependent electron density ne based on the climatological maps constructed from previous observations as it has an advantage of providing altitudinal information on the horizontal asymmetry improvement of proposed ne aided abel inversion and comparisons with electron density profiles inverted from the nmf2 and tec aided inversions are studied using observation system simulation experiment osse comparison results show that all three aided abel inversions improve the ionospheric profiling by mitigating the artificial plasma caves and negative electron density in the daytime e region the equatorial ionization anomaly crests in the f region become more distinct the statistical results show that the ne aided abel inversion has less mean and rmse of error percentage above 250 km altitudes and the performances for all aided abel inversions are similar below 250 km altitudes

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

liptinite in coal and oil source rocks in northern thailand abstract palynological study of northern thailand coal and oil deposits indicates a similar palynological association to that of the borneo region coal petrographic studies of these deposits show variations in the liptinite macerals especially alginite types the oldest of these coal and oil deposits which are of late oligocene to early miocene age are dominated by botryococcus sp or botryococcus related algae thick walled lamaginites and spores and pollen of temperate affinity are found in some areas by contrast thin walled lamaginite is dominant in late middle miocene time resinite suberinite and cutinite are dominant in forest swamp coal deposits whereas alginite cutinite and lycopodium spores are dominant in lacustrine environments exsudatinite is common even at early levels of maturation these liptinite macerals can be major sources of oil and gas

utility of coal petrology for sequence stratigraphic analysis abstract sequence stratigraphy seeks to predict the depositional architecture of sediments based on the principle that their superposition and lateral arrangement are largely determined by the rate at which accommodation is made below depositional base level relative to the supply rate of sediments depositional base level is generally correlated with sea level which in paralic peat coal deposits controls the position of the groundwater table above which oxidation ablation and erosion would occur the current late quaternary sequence is used to discuss some of the constraints on coal formation that stem from the interaction of short and long period modulations on sequence forming eustatic cycles the results show that the mid transgressive systems tract is unlikely to produce significant coal deposits which is supported by a survey of the relevant literature from eight different countries it reveals a bimodal distribution of coal deposits with the strongest mode being situated in the early transgressive systems tract while a broader secondary mode occurs in the early and mid highstand position this concentration contrasts with the complete absence of any significant coal deposits in the early and mid lowstand systems tract and only a low occupancy of the late highstand systems tracts the reasons for this distribution are briefly discussed and attention is drawn to the possible over stating of the coal forming potential of the late lowstand systems tract following a brief discussion of the sequence stratigraphic interpretation of coal measures emphasis is put on the application of sequence stratigraphy to the study of coal seams and their composition at various levels of petrographic detail while in low rank coals botanical affinities contribute much to the lithotype based analysis a genetic assessment of bituminous coal seams relies primarily on physical and chemical palaeo environmental signatures simple properties such as maximum coal thickness low detrital mineral content and maximum preservation of vitrinite particularly of telovitrinite define a good balance between the former rates of accommodation versus peat accumulation iso metamorphic variations in telovitrinite reflectance and its dispersion measured by the coefficient of variation have also contributed to the palaeo environmental interpretation this paper confirms the identification within coal seams of most of the sequence stratigraphically significant surfaces e g sequence and parasequence boundaries transgressive flooding and maximum flooding surfaces it also gives examples of some new ones referred to as accommodation reversal non marine flooding give up transgressive terrestrialisation and paludification surfaces some of these are specific to coal measures but the give up transgressive and accommodation reversal surfaces may have wider significance

a multidisciplinary study of the golbasi harmanli coal seam se turkey abstract this study focuses on the pleistocene golbasi harmanli coal deposit located in the east anatolian fault zone eafz se turkey the principal aim of the study is to determine factors that controlled peat accumulation by means of palaeontological data routine coal analyses proximate ultimate mineralogical composition based on xrd and sem edx and coal petrography the basin infillings consist of alluvial fluvial and lacustrine sediments palaeolake levels along with sedimentation were presumably controlled by the eafz during late pliocene to holocene times the investigated coal bearing zone is composed of a thick coal seam up to 39 m with thin clastic intercalations of fossiliferous claystones palaeontological data from these clastic bands imply that the coal accumulated during middle pleistocene times an uncommon period for the formation of thick coals in turkey we suggest that the movements of the eafz caused rapid subsidence and along with favourable climatic conditions allowed large peat accumulation in a relatively short period of time the results of proximate and ultimate analyses from 29 coal samples obtained from two cores show high ash yields av 32 relatively low sulphur content av 1 8 low net calorific value av 11 6 mj kg and low total carbon content av 35 5 on an air dry basis the mean random reflectances of eu ulminite b indicate a low rank coal maceral compositions and maceral indices indicate that the peat accumulated under limno telmatic mesotrophic conditions with peat forming vegetation being composed of mainly herbaceous plants ostracoda and mollusca fauna from intercalating clastic layers within the coal seam provide important information about the geographic distribution of fossil taxa environmental evaluation of the intercalations and the age of the studied coal seam the ostracoda species gomphocythere geareyi was identified within the coal seam for the first time humphcypris subterranea is the first fossil record of this ostracoda genus in turkey these along with the presence of the gastropoda subspecies bithynia phialensis syriaca imply a transport into the palaeomire via migratory birds from the eastern mediterranean areas discovery of humphcypris subterranea bithynia phialensis syriaca and the african originated genus gomphocythere in the golbasi harmanli coal deposit marks their northernmost worldwide occurrence

sedimentation in a humid interior extensional basin the cenozoic li basin northern thailand facies distributions in extensional basins are controlled by a combination of factors including local and regional tectonics climate hinterland characteristics and base level changes during the mid cenozoic northern thailand was a region in which active basin formation was occurring as a result of regional extension related to major strike slip faults it was also a time when the climate was relatively humid the li basin is one of about 40 cenozoic basins in northern thailand that have a fill of continental facies and it is also one of a number of basins that contain economic coal deposits analysis of the geographical and temporal distribution of facies in the li basin indicates that it had internal drainage fed by rivers that supplied water and sediment to extensive floodplain and lake environments variations in the sediment supply were an important control on the relative development of fluvial channel and muddy overbank facies during periods of high clastic input and peat swamp and lacustrine facies when clastic input was lower changes in palaeosol type and the occurrence of peat deposits indicate that there was a trend towards drier conditions through the period of deposition of the available sections late oligocene to miocene the li basin succession provides an example of a small 500 km 2 extensional basin formed in a humid climate with interior drainage and periods of low clastic sediment supply these conditions resulted in an association of facies deposited in permanent lakes peat swamps wet and dry floodplains fluvial channels and local alluvial fans the relationships between depositional facies and tectonic climatic and sediment supply controls established in this case study may be applicable to other rift and transtensional basins

oil shale and coal in intermontane basins of thailand the mae tip intermontane basin contains cenozoic oil shales in beds up to 1 m 3 3 ft thick interbedded with coal and mudstone the oil shales contain lamosite type alginite and give a maximum oil yield of 122 l mt 29 3 gal ton the beds are laterally continuous for at least 1 5 km 1 0 mi but pass into mudstones toward the basin margin the oil shales originated when peat swamps close to a steep basin margin were flooded by shallow lakes allowing algae to replace rooted vegetation this distinctive oil shale coal assemblage is known from many small intermontane basins in thailand where locally high geothermal gradients suggest potential for hydrocarbons

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

oil shale sedimentology and geochemistry in cenozoic mae sot basin thailand the intermontane mae sot basin thailand contains carbonate rich oil shales in which oil yield mineralogy and major and trace element geochemistry are related to the rock type higher grade oil shale is significantly enriched in silicate minerals quartz feldspars clays and analcite relative to carbonates and in dolomite relative to calcite couplets of organic rich and mineral rich laminae increase in mean thickness from 0 080 mm to 0 670 mm from high to low grade oil shale the organic material consists mainly of lamalginite and yields up to 341 l of oil mt 81 8 gal ton on retorting fish and vascular plant fragments are the main megafossils mappable oil shale sequences 10 m 33 ft thick are interstratified with marlstone sandstone sequences 70 m 230 ft thick markov chain analysis applied to stratigraphic sequences indicates that low grade oil shale passes gradually into high grade oil shale and vice versa the strata are interpreted as the deposits of extensive fresh to brackish lakes with oil shale sequences formed in perennial stratified lakes and marlstone sandstone sequences formed in shallow perennial lakes and subaerially exposed flats dolomite in the oil shales was authigenic the systematic changes in mineralogy and geochemistry between rock types probably reflect a gradient in redox potential from the center to the margins of the lake sandstone and siltstone beds and some carbonate laminae are interpret d as density flow deposits and form a significant proportion of the sequences the episodic deposition of oil shales reflects changes in lake level within the enclosed basin probably due to climatic fluctuations on a 24 000 to 46 000 year scale

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

using natural maturation series to evaluate the utility of parallel reaction kinetics models an investigation of toarcian shales and carboniferous coals germany abstract open system pyrolysis is routinely performed on immature samples in order to determine the kinetic parameters of petroleum generation at both bulk and molecular levels this study tested such predictions for type ii and type iii organic matter by making calibrations with both artificial and natural maturity sequences of toarcian shales posidonia shale 0 48 1 44 rr and carboniferous vitrains 0 74 2 81 rr both natural series showed little or no compositional variability attributable to kerogen type artificially matured samples were prepared by non isothermal heating 0 7 k min of the least mature samples up to end temperatures between 375 and 470 c under either closed or open system conditions measured generation rate versus temperature curves were analyzed assuming a distributed system of activation energies and a single frequency factor in each case the resulting kinetic parameters were then used to assess bulk petroleum formation rates for geological heating conditions in the case of all artificially matured samples measured and predicted bulk petroleum formation rate vs temperature curves for each maturation stage remain within the original envelope defined by the least mature sample despite an upward shift of tmax temperatures this confirms that the reactions taking place during both the pyrolysis measurements and simulated maturation processes are the same involving mainly homolytic cracking a similar pattern of measured and predicted rate curves is reproduced by the natural maturation sequence of the toarcian shales in the maturity range of 0 53 to 1 44 rr suggesting that petroleum generation within these natural systems also results from cracking reactions and therefore that petroleum generation over geological time can be reliably extrapolated from open system pyrolysis of the appropriate immature sample by contrast significant deviations are observed for the natural coal series with measured and predicted rate curves extending beyond the immature envelopes in accordance with the pronounced increase of frequency factors and of protonated aromatic carbon concentrations this behavior is attributed to solid state aromatization reactions which compete with product generation during natural coalification but which are not reproducible to the same extent by experimental heating it is concluded that petroleum generation from vitrinitic coals over geological time cannot be reliably extrapolated from open system pyrolysis of low rank samples

diurnal nonmigrating tides from timed doppler interferometer wind data monthly climatologies and seasonal variations 1 timed doppler interferometer tidi measurements of zonal and meridional winds in the mesosphere lower thermosphere are analyzed for diurnal nonmigrating tides june 2002 to june 2005 climatologies of monthly mean amplitudes and phases for seven tidal components are presented at altitudes between 85 and 105 km and latitudes between 45 s and 45 n westward propagating wave numbers 2 3 and 4 the standing diurnal tide and eastward propagating wave numbers 1 2 and 3 the observed seasonal variations agree well with 1991 1994 uars results at 95 km comparisons between the tidi results and global scale wave model gswm and thermosphere ionosphere mesosphere electrodynamics general circulation model time gcm tidal predictions indicate that the large eastward propagating wave number 3 amplitude is driven by tropical tropospheric latent heat release alone in contrast latent heating and planetary wave migrating tidal interactions are equally important to westward 2 and standing diurnal tidal forcing there is good quantitative agreement between tidi and the model predictions during equinox but the latter tend to underestimate the westward 2 and standing diurnal tide during solstice neither model reproduces the observed seasonal variations of the eastward propagating components

scale properties of microscale convection in the marine surface layer we analyze the scale distribution of coherent water vapor structures in the marine atmospheric boundary layer as measured by a shipboard raman lidar during the combined sensor program march 1996 using a two dimensional continuous wavelet transform coherent structures in the lidar measured water vapor concentration field correspond to locations where covariance with the wavelet is a local extremum scales of the significant structures are identified using a filtered wavelet variance detection density derived from 24 images in a horizontal plane a dominant radius of 14 m is identified using complimentary approaches to the analysis

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

guidelines for assessing the petroleum potential of coaly source rocks using rock eval pyrolysis abstract coaly source rocks are sufficiently different from marine and lacustrine source rocks in their organic matter characteristics to warrant separate guidelines for their assessment using rock eval pyrolysis the rank threshold for oil generation is indicated by the increase in bi s1 toc at rank sr 9 10 tmax 420 430 c ro 0 55 0 6 and the threshold for oil expulsion is indicated by the peak in qi s1 s2 toc at rank sr 11 12 5 tmax 430 440 c ro 0 65 0 85 the pronounced rank related increase in hi s2 toc prior to oil expulsion renders the use of immature samples inappropriate for source rock characterisation a more realistic indication of the petroleum generative potential and oil expulsion efficiency of coaly source rocks can be gained from samples near the onset of expulsion alternatively effective hi values i e his near the onset of expulsion can be estimated by translating the measured his of immature samples along the maturation pathway defined by the new zealand or other defined coal band coaly source rocks comprise a continuum of coaly lithologies including coals shaly coals and coaly mudstones determination of the total genetic potential of coaly source rock sequences is best made using lithology based samples near the onset of expulsion

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

sequence stratigraphy of paralic coal bearing strata an overview abstract sequence stratigraphy arose in the late 1980s to fundamentally change the science of stratigraphy former practice of labeling formations and erecting stratigraphic columns gave place to a dynamic genetic stratigraphic analysis where the main concern is about understanding the history of sedimentation and to establish models able to predict facies born and mainly applied to an environment of petroleum prospecting and exploration sequence stratigraphy has gained entrance to other branches of sedimentary geology the present paper gives a short introduction to sequence stratigraphic concepts and shows an overview of its application on coal bearing strata two case studies one from the early permian coals of the parana basin brazil and one from the lower cretaceous coals of the western canada sedimentary basin illustrate the concepts

comparison of three series of organic matter of continental origin abstract three series of sediments containing land plant derived organic matter were studied they include wells from mahakam delta indonesia miocene douala basin cameroon upper cretaceous and eastern paris basin france paleozoic all of the kerogens and coals isolated from these series can be related to type iii in a van krevelen diagram however they obviously differ in terms of chemical structure as reflected by their pyrolysis gc patterns and by their bitumen composition these observations indicate the variations in the nature of land plant derived sedimentary organic matter and thus differences in quantity and composition of the hydrocarbons which are are released upon maturation based on hydrocarbons potential of the insoluble organic matter and on pyrolysis gc there is no reason to disregard coals and to favor shales as potential source rocks in these two deltaic sequences moreover we assume that the bitumen depletion in coal samples is a reflection of loss by migration which is favored in coals when compared to shales the gc patterns of the residual saturates compared to the pyrolysis gc patterns of the related insoluble coals suggest that migration of hydrocarbons proceeds in these coals without any significant alteration of their distribution at least in the c15 range

sulfur in the changuinola peat deposit panama as an indicator of d the environments of deposition of peat and coal abstract the sulfur s content of coal is often used to infer aspects of paleoclimate trophic state and proximity to marine influence of the mire in which it was deposited in this study the s content of peat in a large back barrier mire complex on the caribbean coast of panama is related to climatic biological and tectonic factors of the depositional environment earthquake generated subsidence is greatest to the southeast leading to drowning of the deposit beneath almirante bay and 40 of the peat is now below sea level coastal mangrove peats with moderately high s content 1 5 wt s and high salinity 1 0 wt dominate the eastern margin and extend beneath the salt water and shallow marine sediments of the adjoining bay marine influence extends only a short distance onsho e except in the vicinity of brackish blackwater creeks that drain the swamp peats associated with these tidal channels are low in salinity 1 0 wt and very high in s 5 to 14 wt s apparently the result of a biogeochemical chain of s reactions leading to the concentration of c s sulfides the western part of the deposit is domed and the vegetation and the peat are concentrically zoned stunted sawgrass dominated vegetation that produces fibric very low s 0 25 wt s peat occupies the central bog plain around the bog plain mixed forest and palm forest swamps produce dense hemic and fine heroic peat with higher s content 0 250 5 wt s the s content is in proportion to the degree of humification of the peat and both are independent of the ph of the groundwater the distribution of forms of organic and inorganic sulfur in the tropical peats are found to be comparable to published values for temperate and subtropical peats despite differences in vegetation and climate the distribution of high sulfur peats in the eastern part of the deposit and low sulfur peats in the western part and the se nw transgression parallel to the trend of the coastline reflects the regional structural trend of coseismic subsidence greatest to the southeast

initial investigations of microscale cellular convection in an equatorial marine atmospheric boundary layer revealed by lidar during the combined sensor program csp in march of 1996 the los alamos national laboratory lanl fielded an advanced scanning raman lidar the lidar was part of a larger suite of micrometeorological sensors to quantify processes associated with the ocean atmosphere interface including intermittency and coherent atmospheric features in the open quotes warm pool close quotes of the tropical western pacific twp near manus island 2 degree s lat 147 degree e long initial inspection of the data has revealed excellent information on the microscale vertical and horizontal spatial and temporal structure of the equatorial marine atmospheric boundary layer mabl the data from this experiment have added to the increasing body of measurements on surface layer convection and intermittency including for the first time the observation of microscale cellular convective structures such as hexagonal patterns associated with rayleigh b acute e nard cells copyright 1997 american geophysical union

nonmigrating diurnal tides in mesospheric and lower thermospheric winds and temperatures abstract this paper presents analyses of nonmigrating diurnal tide signatures in high resolution doppler imager mesospheric and lower thermospheric winds and temperatures a global comparison of both winds and temperature reveals equatorial features corresponding to nonmigrating tides structures interpreted as zonal mean and eastward nonmigrating diurnal tides display consistency between horizontal winds and temperatures the second symmetric mode is prominent in the zonal mean and wavenumber 1 the gravest antisymmetric mode and the gravest symmetric or kelvin mode are the main features in zonal wavenumbers 2 and 3 the amplitudes of the tides generally increase with altitude and maximize within 90 110 km

sequence stratigraphic analysis and the origins of tertiary brown coal lithotypes latrobe valley gippsland basin australia abstract the methods of sequence analysis have been applied to the onshore gippsland basin and in particular to the latrobe valley group coal measures which include up to five coal seams each exceeding 100 m in thickness the methods appear to provide new depositional concepts to the evolution of these seams and the development of coal lithotypes in the eastern half of the latrobe valley evidence for marine transgressions into the coal measures are recorded in most of the interseam sediment splits by the presence of contained foraminifera and dinoflagellates to the west inland these splits pinch out into continuous coal however they can be followed westwards as enhanced organic sulphur levels along sharply defined boundaries between light coal lithotypes below and dark coal lithotypes above the dark lithotype immediately overlying each of these boundaries contains the highest sulphur value and warmer climate pollen assemblages sluiter et al 1995 this volume colorimeter and lithotype logging strongly supports an upwards lightening cyclicity to coal colour at 12 20 m intervals through the approx 100 m thick seams with cycle boundaries defined at sharp planar to undulating surfaces the lightening upward lithotype cycles together with their unique boundary conditions i e enhanced organic sulphur levels warm climatic indicators and laterally equivalent marine clay splits are interpreted as parasequences and parasequence boundaries respectively each major coal seam can comprise up to five parasequences and is interpreted to represent deposition during an outbuilding high stand systems tract at one of several maximum periods of tertiary coastal onlap the top of each major seam shows evidence of truncation erosion on a regional scale and these surfaces are interpreted to represent the sequence boundaries the major seams are usually conformably underlain by marine clays and extensive aquifer sands being deposits of the late transgressive systems tracts the low stands and early parts of the transgressive systems tracts appear not to be represented in the latrobe valley due to its more basin margin location but are probably present down dip in the equivalent marine facies of the seaspray group stratigraphic correlation of the sequence boundaries identified in the coal measures to the adjacent internationally dated marine seaspray group provides a basis for chronostratigraphic correlation of the coal successions to the coastal onlap charts of haq et al exon mesozoic cenozoic chronostratigraphic chart version january 1988 and august 1989 from this dating it appears that each major seam is confined to high stands of third order eustatic cycles it therefore follows that the lithotype cycles parasequences that comprise each seam are related to fourth order eustatic cycles by analogy all the coal cycles may have developed under subtropical conditions as ombrogenous forested peat swamps in a similar manner to the holocene though tropical swamps of indonesia

the kinetics of thermal degradation of individual oil generating macerals calibration with microscopical fluorescence spectrometry and bulk flow pyrolysis abstract kinetic models for petroleum generation describe petroleum formation as either a discrete set of reactions or a continuous distribution of reactions the kinetic models are normally calibrated with data from laboratory experiments this paper discusses theoretical analytical and numerical problems encountered when results of laboratory experiments are extrapolated to geological conditions an alternative approach based on geologically matured samples is presented where quantitative petrological micro fluorometric and hydrogen index data are used in multiple regression analysis to estimate transformation ratios and genetic potentials of compositionally different oil generating entities in source rocks the data are further used in combination with reconstructed time temperature histories to calculate consistent kinetic parameters for the thermal degradation of individual macerals the results both for the genetic potentials and transformation ratios are within the expected range the important aspect of the analysis is that the results were obtained by expressing the transformation ratio as a function of a fluorescence maturity parameter and hence allow increased confidence in the application of fluorescence in maturity studies

productivity control on oil shale formation mae sot basin thailand abstract neogene oil shales from the freshwater lacustrine intermontane mae sot basin western thailand are examined in order to define a oil source rock potential b variations in molecular and isotopic geochemical characteristics and c the influence on source potential of organic matter productivity and preservation twelve samples spanning 7 m of section were examined using conventional isotopic molecular and organic petrographic methods of geochemical analysis temporal resolution is 2700 yr per sample because thermal maturity differences and fluid migration within the sample set are absent and organic matter type input variation is either minor or absent based on visual kerogen analysis we propose that organic matter differences among the samples are caused by variability in surface water productivity all samples are excellent potential source rocks vr 0 4 0 5 ro containing types i and ii organic matter modified van krevelen plot determination consisting of almost 100 fluorescent amorphous kerogen visual kerogen determination numerous diagnostic molecular markers and characteristics are present including perhydro carotene dammaranes norsterane s and novel distributions of tricyclic terpanes stable carbon isotope ratios of kerogens and extract fractions range over 5 and co vary with hydrogen index this covariance is attributed to temporal increases in surface water productivity leading to co2 limiting conditions and consequent increase in 13c of the organic matter in the photic zone during times of elevated productivity increased amounts of 13c enriched organic matter reached the water sediment interface thus times of greater productivity are accompanied by higher 13c and hydrogen index values with 13c related to productivity under co2 limiting conditions and hi related to the relative amount of the water column that was anoxic during deposition our findings suggest that in petroleum geochemical studies involving lacustrine source rocks 13c values must be used with caution as oil oil and oil source rock correlation parameters

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

comparative study of short term diurnal tidal variability examination of the simultaneous temperature measurement from the sounding of the atmosphere using broadband emission radiometry saber instrument on board the thermosphere ionosphere mesosphere energetics and dynamics timed satellite not only confirms the existence of the inversion layer but also reveals the global nature of the inversion suggesting the presence of a transient planetary wave in the mesosphere the large tidal variability therefore is probably a consequence of the interaction between the transient planetary wave and tides this possibility is investigated by using the ncar thermosphere ionosphere mesosphere electrodynamics general circulation model time gcm and by comparing model results with the lidar saber and timed doppler interferometer tidi measurements with a large transient planetary wave specified at the model lower boundary the model is able to produce strong diurnal tidal variability comparable to that from the lidar observation and the modeled temperature inversion is similar to that from the saber measurement the model results suggest that the planetary tidal wave interaction excites nonmigrating tides and modulates the gravity modes and or the rotational modes of the diurnal migrating tide among the nonmigrating tides the diurnal zonally symmetric s 0 component is the strongest and its interaction with the planetary wave leads to a strong diurnal eastward wave number 1 component

eocene krabi basin southern thailand paleontology and magnetostratigraphy we present the magnetostratigraphy of the late eocene krabi section from the krabi basin thailand the investigated section is about 105 m thick and consists of red and yellow siltstones sandstones gray claystones lignites and limestones we collected 86 samples at 43 different stratigraphic levels from the 105 m thick section the samples yielded a paleomagnetic direction and paleomagnetic analyses give favorable demagnetization behaviors two magnetic components can be isolated rock magnetic experiments show that the natural remanent magnetization generally results from the presence of titanomagnetite the first component has roughly the direction of the present day field the second component displays only reversed polarity with a mean direction declination 192 34 inclination 15 5 n 71 95 4 7 k 14 after bedding correction mammalian biostratigraphy indicates a late eocene age correlation to the geomagnetic polarity time scale relies on biostratigraphic data previously proposed for the fauna found in the same section these correlations have been achieved by comparing variations in the sedimentation rate derived from the alternative correlation the proposed correlation puts the krabi section in chron c12r or chron c13r this suggests sedimentation rates of 4 9 and 9 4 cm k y respectively this correlation suggests that the krabi section is older than 31 ma and younger than 34 ma

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

sequence stratigraphic distribution of coaly rocks fundamental controls and paralic examples significant volumes of terrigenous organic matter can be preserved to form coals only when and where the overall increase in accommodation approximately equals the production rate of peat accommodation is a function of subsidence and base level for mires base level is very specifically the groundwater table in paralic settings the groundwater table is strongly controlled by sea level and the precipitation evaporation ratio peat accumulates over a range of rates but always with a definite maximum rate set by original organic productivity and space available below depositional base level groundwater table below a threshold accommodation rate nonzero no continuous peats accumulate due to falling or low groundwater table sedimentary bypass and extensive erosion by fluvial channels this is typical of upper highstand lowstand fan and basal lowstand wedge systems tracts higher accommodation rates provide relatively stable conditions with rising groundwater tables mires initiate and copyright 1997 the american association of petroleum geologists all rights reserved 1manuscript received september 7 1995 revised manuscript received november 25 1996 final acceptance may 5 1997 2exxon production research company 3120 buffalo speedway houston texas 77096 3exxon production research company 3120 buffalo speedway houston texas 77096 present address conoco inc p o box 2197 houston texas 77252 we benefited from the input and assistance of many people of special assistance were the teams involved in collaborative studies with esso australia and esso malaysia p moore m sloan j emmett b burns a partridge s creaney hanif hussein r hill r lovell and m feeley we also thank the rock springs team r beauboeuf p mclaughlin w devlin a carroll y y chen g grabowski jr k miskell gerhardt m farley r webster and j schwalbach group members d curry and j yeakel were always helpful we also enjoyed and profited from many discussions of these concepts with our colleagues outside exxon c diessel r boyd k shanley b zaitlin p mccabe m hendricks a cohen and m kirschbaum we thank the reviewers of company reports whose careful comments on several generations of this work improved it s creaney m feeley j van wagoner f wehr j yeakel and a young f weber and j zullig provided extensive management support k linke translated our sketches into the fine figures herein we value all the help

tropospheric tidal effects on the middle and upper atmosphere 1 numerical experiments that explore the effects of tides of tropospheric origin on the upper and middle atmosphere reveal strong signatures of an eastward propagating zonal wave number 3 diurnal tide de3 which peaks near 110 km and penetrates into the upper thermosphere we demonstrate that nonmigrating tidal dissipation dominated by de3 effects in the upper mesosphere and lower thermosphere mlt strongly accelerates the zonal mean wind field affecting both the altitude and magnitude of the low latitude jets we also quantify for the first time a stationary planetary wave 4 oscillation spw4 in the mlt which is excited by nonlinear interaction between the de3 and the migrating diurnal tide dw1 our results suggest that the spw4 modulates the de3 mlt response and may impact the e region dynamo as well as ionospheric and thermospheric signatures at much higher altitudes

tidal signatures and aliasing in temperature data from slowly precessing satellites 1 thermosphere ionosphere mesosphere electrodynamics general circulation model time gcm data are used to simulate tidal patterns in satellite borne observations of the mesosphere and lower thermosphere mlt region the results are given for the measurement geometry of the sounding of the atmosphere using broadband emission radiometry saber instrument though the technique is applicable to any satellite based instrument time gcm tides are sampled along the instrument measurement track and analyzed in terms of ascending descending orbit node differences our simulations show a significant aliasing e g of migrating and nonmigrating diurnal and semidiurnal components into tidal fields of observed zonal wavenumbers s 0 above the mesopause the model tides induce a 10 k bias in daily means of zonally averaged temperatures an estimate of the tide induced vertical displacement of air parcels is given assuming tidal motions are adiabatic corresponding signatures are expected to be present in mlt observations of chemical species addressing tidal sampling issues is of general interest for comparing satellite observations with models climatologies and other measurements

development of cenozoic basins in thailand abstract there are over 60 cenozoic basins distributed in various parts of thailand both onshore and offshore these basins are mainly n s trending half grabens or grabens and most were initiated in the late oligocene the structural framework of the basins is generally governed by n s trending extensional faults which are spatially related to the movement of the nw se and ne sw trending strike slip faults that have been active since the oligocene the nw se faults are the principal dextral strike slip faults whereas the ne sw faults are the conjugate sinistral strike slip faults the collision of the india craton with southern asia since 40 50 ma caused clockwise rotation of southeast asia and movements on the strike slip faults with the associated development of cenozoic basins in this region four major cenozoic basins mergui pattani malay and phitsanulok contain up to 8000 m of sediments generally the cenozoic fills are continental sediments except in the mergui basin in the andaman sea where the sedimentary fill is mainly marine sediments fluviatile with occasional lacustrine deposits were prominent in the gulf of thailand and onshore basins during the oligocene to early miocene from early to middle miocene widespread perennial lake conditions were well developed in the onshore basins and in the western graben area of the gulf of thailand a change in tectonic and or climatic conditions took place in the middle to late miocene times resulting in the cessation of perennial lake conditions and development of a regional unconformity

petrology of a suite of sedimentary rocks associated with some cole bearing basins in northwestern thailand abstract a number of basins in northwestern thailand contain thick sequences of cenozoic sedimentary rocks oil shales and coals are prominent lithologies within these sequences and occur together in some basins most of the sequences are however dominated by either oil shales or coals the major oil shale deposit is in the mae sot basin but oil shales also occur in the ban huay dua mae moh ban pa ka li mae teep ban na hong and jae hom basins drilling and detailed mapping in the mae sot basin indicate thick sequences of oil shales and organic petrological studies show that they contain abundant lamalginite trace amounts of telalginite liptodetrinite bitumen resinite and huminite inertinite are also present in some of the rocks the parts of the sequences rich in authigenic minerals are in general petrographically similar to green river formation lamosites where clay silt sized epiclastics are more abundant similarities exist to australian tertiary lamosites vitrinite reflectance date from the oil shales and associated coals indicate a low level of maturity oil shales from the other basins are petrographically similar to the mae sot lamosites however some differences do exist the mae sot and other lamosites were deposited in lacustrine environments that probably had highly variable water depths

relative sea level control of deposition in the late permian newcastle coal measures of the sydney basin australia abstract accumulation of the 400 m thick late permian newcastle coal measures of the sydney basin was controlled by changes in relative sea level three 3rd order sequences which constitute the coal measures consist of 4th order depositional sequences of fluvial conglomerate coal and small paralic lacustrine deltas crevasse splays deposited on a coastal plain landward of a marine shoreline each 4th order sequence was deposited during a single 4th order relative sea level cycle following falls in relative sea level alluvial conglomerates derived from the new england orogen filled incised valleys above sequence boundaries forming lowstand systems tracts sigmoidal conglomerates with giant crossbeds were deposited as alluvial fill in compactional moats formed at the toes of abandoned paralic deltas alluvial sediments passed through the coastal plain directly to the marine shoreline causing the shoreface to prograde rising relative sea level caused siliciclastic sedimentation to wane during these hiatuses in the transgressive systems tract a rising water table stimulated peat mire growth blanketing the entire non marine area when the vertical accumulation of peat was outpaced by increasing rates of rising relative sea level transgressing lagoons interdistributary bays and lakes inundated the mires above maximum flooding surfaces continuing relative sea level rise in the highstand systems tracts caused paralic lacustrine crevasse splays crevasse subdeltas and small deltas to prograde westwards into the newcastle half graben from a volcanic source on the offshore uplift at this time of rising base levels sediments were trapped on the coastal plain while the marine shoreface was starved falling relative sea level terminated paralic lacustrine delta progradation and initiated exposure and erosion to repeat the cycle and initiate another 4th order sequence two source areas supplied sediment into the newcastle half graben an easterly source on the offshore uplift shed volcanic detritus into the newcastle coalfield via paralic lacustrine deltas and the new england orogen shed volcano lithic detritus via braided streams the supply from the new england orogen was switched on or increased by a fall in relative sea level while supply from the offshore uplift was switched off reduced or diverted and vice versa during a rise in relative sea level increasing rates of 2nd order falling relative sea level resulted in an upward change from predominantly marine shoreface and coastal plain sedimentation to predominantly fluvial sedimentation in the upper newcastle coal measures

structural evolution of the li basin northern thailand exposures in the oligocene to miocene section of coal mines in the li basin of northern thailand show a complex structural evolution the basins formed under approximately east west extension nw to north south striking normal faults are dominant with some east west normal faults also being present but much less frequently episodically compressional and or strike slip events affected the basin creating new east west to ne sw striking thrusts and folds and inverting some normal faults the latest episode of compression formed nw se to north south striking thrusts and folds cross cutting structures reactivation of structures syn sedimentary deformation and unconformites help to constrain the relative timing of structural events at least five episodes of predominantly nnw sse to ne sw oriented compression interrupted the extensional development of the basin the compression was probably related to the escape tectonics of the himalayan orogeny the episodic nature of the compression and extension is inconsistent with either simple strike slip related opening of the rift basins or simple extension the data from the li basin indicate a reappraisal of current tectonic models for the region is necessary

relative sea level changes recorded by paralic liptinite enriched coal facies cycles middle jurassic muslingebjerg formation hochstetter forland northeast greenland abstract the middle jurassic muslingebjerg formation of hochstetter forland northeast greenland consists of a succession of shallow marine sandstones encasing four coal seams formed in low lying coastal mires the seams are up to 3 45 m thick and contain coal facies cycles with high liptinite contents up to 70 vol the cycles generally start with huminite rich bright or banded coal and end with dull coal or clayey coal coaly claystone the dull coals are characterized by a high proportion of liptinite commonly resinite and often mineral matter liptodetrinite resinite and cutinite dominate the liptinite maceral group similarity in the relative proportions of the liptinite macerals in the bright and dull coals and the general association of bright coal and dull coal with a high resinite concentration suggest that the dull coals represent a residue after selective removal of ligno cellulosic tissues in the precursor peat of primarily the bright lithotype the clayey coal coaly claystone lithotypes have high contents of mineral matter and commonly contain alginite and pyrite occurrence of pyrite in levels with high diasterane c 27 c 29 ratios and sometimes also alginite in the clayey coal coaly claystone lithotypes indicates a marine influence during flooding of the mires this suggests a causal link between base level rise in the coastal mires and relative sea level rise accommodation space available for thick peat accumulations was governed by overall relative sea level rise and the dulling upward cycles record outpacing of peat accumulation due to accelerated rise in base level relative sea level the muslingebjerg formation consists of four depositional sequences beginning with a thick coal seam resting on a sequence boundary peat accumulation reflects onset of base level rise in the coastal area and the coals represent the lower part of the transgressive systems tract the overlying shoreface sandstones form the upper part of the transgressive systems tract and a progradational highstand systems tract alternatively the two lower seams in the succession may form a transgressive regressive couplet separated by a lagoonal sandstone split in this case a sequence boundary occurs at the top of the upper regressive seam the dulling upward cycles within the coal seams represent parasequences or possibly higher order sequences minimum age estimates suggest that they accumulated over 4000 11000 yr

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

association of oil source algae in some tertiary basins northern thailand abstract a coal petrographic study of sediments including coals oil shale and oil source rocks in the fossil fuel deposits of northern thailand revealed changes in alginite associations in the lower part of these tertiary deposits especially in the fang oilfield alginite a a botryococcus sp was the only type of alga found later the association of botryococcus braunii pila algae thick walled alginite b and temperate palynomorphs were recognized in many coalfields as well as in the middle part of the deposits in the fang basin their ages were late oligocene to early miocene in the upper part of the fossil fuel deposits alginite b is dominant in many basins together with botryococcus related taxa such as pila algae reinschia and fresh water dwelling ferns in the mae sod basins reinschia was found to be dominant in the northern part whereas lamaginite dominated in the south showing different environmental conditions in different parts of the basin during deposition these different associations indicate changes in depositional environments in northern thailand resulting from climatic and or sea level changes during tertiary time

occurrence and distribution of sulfur in peat forming environments of southern florida abstract cores and surface samples of peats from the everglades mangrove region of southern florida were analyzed for total sulfur and pyritic sulfur these values were compared with the petrographic botanical components of the peats as determined from point counts of oriented microtome sections pyrite occurs as individual euhedral crystals loosely packed framboids and lenses or crusts of minute crystals framboids and minute crystals are often associated with organic matter and sometimes with bacteria and fungi pyrite tends to selectively occur in void spaces in or between peat tissues in samples containing very small amounts of pyrite framboidal pyrite is the prevalent form marine to brackish peats contain the highest pyrite and total sulfur contents with brackish peats generally containing more pyrite than marine peats pyrite tends to be lower in all peats within 30 cm of the surface whether marine or brackish burial of freshwater peats beneath marine or brackish peats tends to increase the total sulfur and pyritic sulfur in the underlying peats burial beneath brackish water clay rich deposits such as splays tends to increase total sulfur and pyritic sulfur in the underlying deposits more than burial beneath less clay rich deposits

climatology of upward propagating diurnal and semidiurnal tides in the thermosphere 1 a major challenge in delineating and understanding the space weather of the ionosphere thermosphere system is the lack of global tidal observations in the 120 400 km thermospheric gap between satellite remote sensing and in situ tidal diagnostics this paper aims to close this gap by presenting an observation based climatological tidal model of the thermosphere ctmt of self consistent upward propagating migrating and nonmigrating diurnal and semidiurnal tides from 80 400 km and pole to pole for moderate f10 7 110 sfu solar flux conditions ctmt includes the 6 8 most important diurnal semidiurnal tidal components for temperature density and zonal meridional and vertical winds and is based on hough mode extension fits to 2002 2008 mean timed satellite tidal diagnostics in the mesosphere lower thermosphere mlt validation with independent 2002 2008 champ tidal diagnostics f10 7 105 sfu around 400 km proves that the approach captures nonmigrating tides well indicating that these waves propagate directly upward without significant tidal forcing occurring in the thermosphere notable exceptions are the dw2 and d0 components that are most likely generated in situ by nonlinear interaction forcing in the upper thermosphere ctmt is suitable for driving upper atmosphere models that require self consistent tidal fields in the mlt region as a lower boundary condition it does not include migrating tides due to in situ euv absorption in the upper thermosphere but allows us to quantitatively assess thermospheric variability due to tides from the lower atmosphere this is done by discussing longitude latitude maps of reconstructed diurnal and semidiurnal tidal variations as function of altitude and local time

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

satellite observations of mean winds and tides in the lower thermosphere 1 aliasing and sampling issues 1 the canadian middle atmosphere model a general circulation model extending up to 200 km is used to analyze the impact of aliasing and data gaps on satellite observations of zonal mean winds and migrating tides in the lower thermosphere focus is placed on measurements from the wind imaging interferometer windii mock data sets are constructed by sampling daily zonal mean and migrating tides from the model like the satellite previously unverified assumptions that satellite observations of the zonal mean zonal winds and the meridional component of the diurnal tide winds are largely unaffected by aliasing are confirmed of the two the meridional component of the diurnal tide is more robust the amplitude of the zonal component of the diurnal tide is not strongly affected by aliasing tidal phase is nearly unaffected gaps in the windii data do not adversely affect the results provided sufficient local time coverage is available the analysis suggests that more subtle features in the windii observations such as the tidally driven cell like structures in the zonal mean meridional wind at low latitudes may be observable issues pertaining to the sampling interval and the use of daytime only data are also addressed sampling every second or third day provides nearly as good results as sampling every day and that using daytime only data results in substantial biases in the zonal mean zonal winds in the lower thermosphere the latter underscores the importance of the accurate removal of the migrating diurnal tide from climatologies generated from daytime only satellite data

coal facies in a cenozoic paralic lignite bed krabi basin southern thailand changing peat forming conditions related to relative sea level controlled watertable variations abstract the cenozoic krabi basin in the southern part of peninsular thailand contains about 112 million tons proven coal reserves at present coal is only produced from the bang mark mine located in the southern part of the basin where the main lignite bed is 7 20 m thick the lignite bed occurs in an overall paralic succession the present paper investigates the depositional conditions of an approximately 8 m thick lignite bed main seam in the bang mark mine using organic petrography including maceral ratios and geochemistry the results are further interpreted in a sequence stratigraphic context the lignite is of low rank and is completely dominated by huminite indicating generally oxygen deficient conditions in the precursor mire very low inertinite contents suggest rare occurrences of wildfires the lower part of the lignite bed represents a topogenous fresh water peat mire with open water areas that in few cases may have experienced influx of saline water the peat mire was subjected to periodic inundations and deposition of siliciclastics tissue preservation was relatively poor the upper part of the lignite bed represents a slightly domed fresh water ombrogenous peat mire with a stable watertable and a balance between peat accumulation and accommodation space creation that favoured preservation of plant tissues in general the mire vegetation changed from less woody in the topogenous mire to more arborescent in the ombrogenous mire where plants with suberinised wood cell walls also were more frequent decompacted the lignite bed corresponds to a minimum 11 m thick peat deposit that records from 22 000 to 55 000 years of peat accumulation watertable rise in the peat mire was controlled overall by relative sea level rise in a sequence stratigraphic context the lignite bed overlies a terrestrialisation surface tes sensu diessel 2007 and the lowermost part records peat formation during a falling watertable and a decreasing accommodation peat accumulation ratio terrestrialisation an accommodation reversal surface ars sensu diessel 2007 indicates a change to paludification style of peat formation characterised by rising watertable and a high accommodation peat accumulation ratio another ars marks a gradual change to a situation with a balanced accommodation peat accumulation ratio the overall watertable rise throughout peat formation but at a gradually slower rate from base to top suggests that the lignite bed could be located in the late transgressive systems tract tst

predicting the quantities of oil and gas generated fromaustralian permian coals bowen basin using pyrolyticmethods abstract the aim of the study was to establish kinetic parameters for gas and oil generation and totest the applicability of the kinetic models to petroleum generation through comparisons withnatural maturity coal sequences 433 c t max ro ro ro modelled ro calculated ro calculated

sources of nonmigrating tides in the tropical middle atmosphere 1 temperature measurements from the cryogenic infrared spectrometers and telescopes for the atmosphere crista experiment taken during the u s space shuttle mission sts 66 in november 1994 provide a variety of zonally symmetric and asymmetric tidal signatures in the altitude range from 40 90 km the most prominent zonally asymmetric tidal pattern is identified to be the westward propagating nonmigrating diurnal tide of zonal wavenumber 2 s 2 this mode has an amplitude of approximately half the amplitude of the migrating s 1 component of the diurnal tide the observational findings are compared to model results from the global scale wave model gswm and from the thermosphere ionosphere mesosphere electrodynamics general circulation model time gcm gswm and time gcm account for different tidal sources and therefore allow an analysis of the tidal forcing responsible for the observed signatures the gswm tidal forcing in the model version used is based upon latent heat release associated with tropical deep convection while nonmigrating tides in the time gcm are predominantly forced by nonlinear interactions between the migrating diurnal tide and stationary planetary waves it is shown that the latter mechanism forces a large part of the s 2 mode while the stationary zonally uniform s 0 diurnal nonmigrating tide is mainly driven by latent heat release this result suggests that dynamical models for the mesosphere lower thermosphere mlt region need to account for the tropospheric latent heat source and stationary planetary wave activity in order to predict realistic longitudinal diurnal tidal variability

the geology mineralogy petrography and geochemistry of the miocene dursunbey coal within fluvio lacustrine deposits balikesir western turkey abstract the dursunbey coalfield a typical example of coalfields in the western anatolia hosts a mineable coal seam about 9 0 m coal thickness with altered tuff layers within early miocene fluvio lacustrine sequences the aim of this study is to identify peat accumulation conditions and factors controlling the mineralogy and geochemistry of this seam the standard coal features and petrographical mineralogical and elemental compositions display changes throughout the seam ash yields display decreasing trends towards to the upper parts of seam while total c contents and gross calorific values are increasing furthermore the coal facies patterns evidence changes of depositional conditions and vegetation in the palaeomires during initial stages of peat accumulation the contribution of herbaceous peat forming plants were more common and palaeomires were open to detrital inputs whereas woody peat forming were becoming predominant and the water table was stable and high which caused development of anoxic conditions during late stages therefore the content of detrital minerals such as quartz and clay minerals illite smectite and chlorite increases in the lower parts of seam while that of pyrite increases in the upper parts in addition the sem edx data show that matrices of clay mineral aggregates are illitic in composition in the lower parts of seam while those of smectite prevalence are more common below and above altered tuff layers interestingly authigenic rhomboid k feldspar grains are observed within smectite clay aggregates in the samples from the upper parts of seam framboidal pyrite grains and clusters were also commonly identified from these samples as well this data shows that synchronous volcanic inputs were altered within a hydrologically closed system under slight acidic to neutral conditions during late syngenetic stages the enriched elements such as cr ni cs and v display moderate to strong positive correlations with ash yields while al2o3 and k2o indicate an aluminosilicate affinity clay mineral and feldspar considering the presence of metamorphic and ophiolitic rocks in the basement and the adjacent areas clastic inputs into the palaeomire seems to be controlling aluminosilicate affiliated elements additionally the sem edx analyses denoted that ni and as are associated with pyrite the ni and as bearing epigenetic pyrite infillings are mostly identified in coal samples below altered tuff layers hence as and ni enrichments are controlled by precipitation of leached pore waters from altered tuff layers nevertheless as and ni bearing syngenetic pyrite grains and clusters are related with the development of anoxic conditions within palaeomires this could also favour a mo and u enrichment which is another testimony for synchronous volcanic inputs altered under anoxic conditions overall high detrital input ratios from adjacent areas during initial stages of peat accumulation in the study area controlled by enrichments of aluminosilicate affiliated elements whereas during late stages of peat accumulation the development of a hydrologically closed system and redox conditions within the palaeomire caused as ni mo and u enrichments and the formation of smectite and authigenic k feldspars

the petroleum generation potential and effective oil window of humic coals related to coal composition and age abstract a worldwide data set of more than 500 humic coals from the major coal forming geological periods has been used to analyse the evolution in the remaining hydrogen index hi and total quality index qi generation potentials with increasing thermal maturity and the effective oil window oil expulsion window all samples describe hi and qi bands that are broad at low maturities and that gradually narrow with increasing maturity the oil generation potential is completely exhausted at a vitrinite reflectance of 2 0 2 2 ro or tmax of 500 510 c the initial large variation in the generation potential is related to the original depositional conditions particularly the degree of marine influence and the formation of hydrogen enriched vitrinite as suggested by increased sulphur and hydrogen contents during initial thermal maturation the hi increases to a maximum value himax similarly qi increases to a maximum value qimax this increase in hi and qi is related to the formation of an additional generation potential in the coal structure the decline in qi with further maturation is indicating onset of initial oil expulsion which precedes efficient expulsion liquid petroleum generation from humic coals is thus a complex three phase process i onset of petroleum generation ii petroleum build up in the coal and iii initial oil expulsion followed by efficient oil expulsion corresponding to the effective oil window efficient oil expulsion is indicated by a decline in the bitumen index bi when plotted against vitrinite reflectance or tmax this means that in humic coals the vitrinite reflectance or tmax values at which onset of petroleum generation occurs cannot be used to establish the start of the effective oil window the start of the effective oil window occurs within the vitrinite reflectance range 0 85 1 05 ro or tmax range 440 455 c and the oil window extends to 1 5 2 0 ro or 470 510 c for general use an effective oil window is proposed to occur from 0 85 to 1 7 ro or from 440 to 490 c specific ranges for himax and the effective oil window can be defined for cenozoic jurassic permian and carboniferous coals cenozoic coals reach the highest himax values 220 370 mg hc g toc and for the most oil prone cenozoic coals the effective oil window may possibly range from 0 65 to 2 0 ro or 430 to 510 c in contrast the most oil prone jurassic permian and carboniferous coals reach the expulsion threshold at a vitrinite reflectance of 0 85 0 9 ro or tmax of 440 445 c

the oleaginous botryococcus from the triassic yanchang formation in ordos basin northwestern china morphology and its paleoenvironmental significance high abundance but rather low diversity algal fossils were found in the hydrocarbon source rocks of the ch 7 2 ch 7 3 section triassic yanchang formation in the xifeng area of southwest ordos basin which are mainly composed of prolific leiosphaeridia and botryococcus botryococcus colonies are of various forms the majority is nubbly with some of cluster and cotton shape the nubbly colonies appear globular cordiform ternate petal obtuse triangle chrysanthemum shape and so on most botryococcus are saffron or brown and are frequently covered with clay under transmission microscope and shows strong yellow and light brown under fluorescence microscope botryococcus could live in freshwater and brackish water the botryococcus colonies that lived in fresh water are small with small single cells arranged radially with undulant or indented edges the botryococcus colonies that lived in brackish water are bigger with larger single cells arranged irregularly with slippery contours the most of botryococcus are discovered from the organic rich argillaceous sediment with abundant pyrites in the semi and deep lake facies and shows they were preserved in low energy reducing environments taphonomic characteristics of various microfossils and the present of pediastrum in the phytoplankton flora indicate that they are in situ or near burial the lake area of the ordos basin was gradually expanding and reaching its most extensive flood surface in the ch 7 of yanchang formation interval during the middle and late triassic with warm climate plentiful rainfall and luxuriant vegetation as determined by the environmental analysis with botryococcus in xifeng area the presence of two ecological types of botryococcus indicates that the salinity of lake water was fluctuating in the ch 7 interval the occurrence of symbiotic acritarchs and geochemical salinity indices show that the ordos lake was a typical fresh water lake which was gradually desalted and its salinity fluctuation was narrow during the mid later triassic the ecological type of the palynological flora discovered from the ch 7 to ch 8 in xifeng area is similar to that from the fuxian lake with abundant botryococcus in the yungui plateau of china these findings imply that the ordos basin was in a lower latitude area of temperate to subtropical climate during the middle and late triassic

the effects of clastic sedimentation on organic facies development within a tertiary subbituminous coal bed powder river basin montana u s a abstract the anderson dietz coal is a 25 m thick bed that splits eastward into three benches the anderson dietz 1 and dietz 2 each separated from the other by as much as 45 m of detrital sedimentary rocks petrographic and chemical analyses of the anderson and dietz 1 coal benches suggest that detrital sediments now lithified between the benches were introduced after the peat surface had subsided as a result of either fire or differential compaction of underlying sediments sediments associated with this event had a limited effect upon the quality of the anderson and dietz 1 coal benches ash yields and sulfur contents are elevated only at the very top and bottom of the benches in areas where the benches are not split sulfur content and maceral types indicating degradation increase only in a thin zone 1 m thick that is laterally equivalent to the split sediments however ash yields in this interval increase only slightly 2 5 this indicates that while little sedimentation occurred the peat which formed the coal was inundated by higher ph surface and ground water causing the degradation of plant material

tidal signatures in temperature data from crista 1 mission temperature measurements in the stratosphere and mesosphere were taken during the first cryogenic infrared spectrometers and telescopes for the atmosphere crista 1 mission using co2 emissions these measurements range from 13 to close to 100 km and individual temperature measurements have a precision of 1 k the crista orbit was circular at an inclination of 57 so local time variations during the 7 day mission were small for a given latitude and orbit leg zonal averages of the data show significant structure in the vertical and as a function of latitude temperature differences between the zonal mean data from the ascending and descending portions of the orbit are of the form expected from the diurnal tide the maximum zonal mean difference is 20 k and occurs over the equator at an altitude of 75 km zonal variations in the temperature difference indicate that the tidal amplitude is not uniform at all longitudes at the equator the maximum amplitude 30 k appears over the african sector and the minimum 10 k over the pacific sector this variation is most likely a nonmigrating wavenumber 2 diurnal tide although other less plausible possibilities exist to facilitate comparisons with model results the temperature variations are converted to equivalent vertical displacements assuming the tidal motions are adiabatic such an approach is appropriate in the mesosphere where diurnal variations due to radiative effects are small and reduces the dependence of the measured temperature amplitude on the background temperature profile equivalent vertical displacements are also calculated using results from the global scale wave model for the most part the model results and observations are in excellent qualitative and good quantitative agreement from the tropopause to the mesopause however the observed vertical wavelength is smaller and its amplitude in terms of equivalent displacement is smaller in the upper mesosphere than that in the model the decrease in amplitude is consistent with that expected from the transition from equinox to solstice conditions

longitudinal structure of the equatorial ionosphere time evolution of the four peaked eia structure 1 longitudinal structure of the equatorial ionosphere during the 24 h local time period is observed by the formosat 3 cosmic f3 c satellite constellation by binning the f3 c radio occultation observations during september and october 2006 global ionospheric total electron content tec maps at a constant local time map local time tec map referred as lt map can be obtained to monitor the development and subsidence of the four peaked longitudinal structure of the equatorial ionosphere from lt maps the four peaked structure starts to develop at 0800 1000 lt and becomes most prominent at 1200 1600 lt the longitudinal structure starts to subside after 2200 2400 lt and becomes indiscernible after 0400 0600 lt in addition to tec ionospheric peak altitude also shows a four peaked longitudinal structure with variation very similar to tec during daytime the four peaked structure of the ionospheric peak altitude is indiscernible at night with global local time maps of ionospheric tec and peak altitude we compare temporal variations of the longitudinal structure with variations of e b drift from the empirical model our results indicate that the observations are consistent with the hypothesis that the four peaked longitudinal structure is caused by the equatorial plasma fountain modulated by the e3 nonmigrating tide additionally the four maximum regions show a tendency of moving eastward with propagation velocity of several 10 s m s

mid latitude temperatures at 87 km results from multi instrument fourier analysis using a novel fourier fitting method we com bine two years of mid latitude temperature measurements at 87 km from the high resolution doppler imager the colorado state university lidar and the peach mountain interferometer after accounting for calibration bias sig nificant local time variations on the order of 10 k were ob served stationary planetary waves with amplitudes up to 10 k were observed during winter with weaker wave ampli tudes occurring during other seasons because of calibration biases among these instruments we could estimate the an nual mean temperature to no better than 193 5 4 8 5 k 1991 and recent work by leblanc et ed 1999 we present a methodology for making statistical estimates of mid latitude temperature fields using a combination of satel lite and ground based data results at a height of 87 km are presented here to illustrate the method and its potential future use with larger multi instrument data sets figure la shows the combined longitudinal and tempo ral sampling pattern of the temperature field between 41 o 4 1 o n at 87 km over a two year period from the high resolution doppler interferometer hrdi ortland et at

organic facies development within middle jurassic coal seams danish central graben and evidence for relative sea level control on peat accumulation in a coastal plain environment abstract during middle jurassic times peat accumulated in coastal plain environments in an overall transgressive setting in the sogne basin danish central graben in the north sea the coal seams occur in nonmarine to marginal marine deposits coal petrographic analyses of the seams in the west lulu 2 well supplemented with a sequence stratigraphic analysis suggest that peat accumulation was controlled by relative sea level changes in west lulu 2 the coal bearing upper part of the middle jurassic is divided into sequences a and b the sediments of sequence a are part of a transgressive systems tract whereas the overlying sequence b contains lowstand and transgressive systems tract deposits the coals are situated in the transgressive systems tracts the coal seams formed during a rapid relative sea level rise are generally characterized by petrographic features related to a permanently high groundwater table coals formed during a slow rise typically are drier in their petrographic composition the highest pyrite contents are observed in the wet coals the coal seams represent terrestrial equivalents to marine flooding surfaces or to transgressive surfaces if they are situated at the base of a transgressive systems tract a thick coal seam zone is associated with the stratigraphic level of the maximum flooding surface which correlates with the time of formation of the highest accommodation space

composition and organic maturity of middle jurassic coals north east greenland evidence for liptinite induced suppression of huminite reflectance abstract middle jurassic coals from kuhn o north east greenland may contain up to 85 vol liptinite principally resinite up to 68 6 vol the coals are thus petrographically comparable to the middle jurassic muslingebjerg formation coals at hochstetter forland approximately 40 50 km to the north and they are inherently excellent petroleum source rocks liptinite poor 6 0 vol coal samples from both kuhn o and hochstetter forland yield mean random huminite reflectance values of 0 49 0 53 ro implying a rank of sub bituminous a above a threshold value somewhere between 3 and 24 vol resinite and 6 and 35 vol total liptinite significant reflectance suppression is induced and between 24 and 69 vol resinite and 35 and 85 vol total liptinite a nearly linear inverse relationship exists between the content of liptinite resinite and the mean random reflectance values at the highest liptinite resinite contents reflectance suppression may be up to 0 23 ro the reflectance suppression is related to bitumen adsorption caused by bitumen expulsion from resinite and total reflectance distributions of the huminite fractions suggest that the reflectance of all huminite macerals is lowered with increasing liptinite resinite content

structure of the terdiurnal tide at 95 km satellite wind observations from the high resolution doppler interferometer hrdi instrument on the upper atmosphere research satellite uars are used to describe the latitudinal structure and seasonal variation of the terdiurnal 8 hour atmospheric tide at 95 km the amplitude of the annual average tide is 5 m s meridional and 15 m s zonal within the range observed 60 s to 60 n the maximum amplitudes are found during fall and winter at midlatitudes only weak temporal correlations with the diurnal and semidiurnal tides are seen on the monthly time scales resolved

nonmigrating diurnal tides in the equatorial middle atmosphere abstract data from the nimbus 7 limb infrared monitor of the stratosphere lims are used to extend the analysis of diurnal tides in the middle atmosphere to include the zonally symmetric and eastward propagating components these modes show vertical and meridional structures that are generally consistent with the predictions of linear tidal theory the zonal and meridional wind fields are calculated from the tidal temperatures diurnal perturbations in lims temperature and derived winds agree well with equinoctial model calculations comparisons with day night differences of radiosonde temperature and rocket winds show qualitative agreement in vertical structure and amplitude the zonally symmetric and eastward migrating tidal components show a higher degree of temporal variability than the sun synchronous component these modes at times contribute substantially to the diurnal signal in wind and temperature with combined amplitudes equal to or in excess of the amplitude of the main migrating diurnal tid

anatomy of recent and peatified calluna vulgaris stems implications for coal maceral formation abstract anatomical characteristics of peatified calluna vulgaris stems isolated from a selection of northwest european raised bog peat deposits were compared with intact stems in order to reveal anatomical modifications caused by the peatification process four main decomposition processed were discerned 1 loss of structural integrity of cell walls and cell inclusions 2 gelification and swelling of cell walls 3 discolouration of cell walls and 4 deposition of matter in cell lumina fibre tracheids and wood parenchyma appear to be the most affected cell types the two main decomposition trends discerned in these were related to different fungal types precipitation of decay products was mainly observed in vessels bark tissues primary xylem and medullary parenchyma were characterized by an excellent anatomical preservation in the first stages of peatification a rapid decrease in cell contents was observed in bark tissues swelling and gelification was mainly seen in cell walls of the cambium and vessels we conclude that different types of cell walls respond differently to decay conditions this is probably related to differences in the original cell wall chemistry a high intra and intracellular variability in degree of preservation was sometimes observed in identical tissues the microscopic variability arising during peatification of wood and bark testifies to the heterogeneity of coal macerals derived from these tissues