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

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

petrography palynology and depositional environments of the early miocene oberdorf lignite seam styrian basin austria abstract an early miocene ottnangian lignite seam up to 36 m thick occurs in the oberdorf trough at the northwestern margin of the styrian basin it forms part of the fluvial koflach voitsberg formation petrographic and palynologic data together with ash yield and sulphur content of samples from two boreholes and two surface profiles have been used to study vertical and horizontal coal facies variations numerous partings and a high ash yield show that the lignite originated in a topogenous mire petrographic indices and palynological data suggest a wet forest swamp paleo environment a fluvial main parting with channel sediments at the eastern margin of the oberdorf trough and overbank sediments in its central part splits the lignite into a lower and an upper seam the lower seam consists of a lower high ash part with frequent splittings and a higher low ash part the upward decrease in number and thickness of silty clayey partings interpreted as crevasse splay deposits reflects the withdrawal of the fluvial sediment source coal composition is characterized by an upward increase in detro xylitic coal and in tissue preservation a good correlation between tissue preservation and percentages of taxodiaceae cupressaceae pollen suggests that this is mainly a result of an increasing contribution of decay resistant gymnosperms conifers the upper seam is also ash rich abundant inertinite at the eastern margin of the oberdorf trough is related to fire episodes inside or outside the mire main features of the upper seam in the central basin are an upward increase in tissue preservation and in percentages of taxodiaceae cupressaceae pollen high sulphur contents in the fresh water lignite are a result of a concentration of sulphate rich waters above the impermeable floors of the lower and upper seams carbonate rich surface waters from the graz palaeozoic and raasberg sequence raised the ph value and controlled sulphur and ash contents in those parts of the lower seam which are uninfluenced by the basal sulphur enrichment palynomorph spectra are dominated by taxodiaceae cupressaceae pollen and pollen from plants living in a mixed mesophytic forest pollen from aquatic and reed plants are rare the ratio between arctotertiary and paleotropic pollen is close to one and supports the early miocene age of the lignite the detected pollen spectra point to warm temperate subtropic and humid conditions

coal characteristics palynology and palaeoenvironmental interpretation of the yenikoy coal of late oligocene age in the thrace basin nw turkey abstract the yenikoy coal field is located in a narrow area between the black sea coast and the istranca standrja mountain in the thrace basin the aims of this study are to characterize coal petrographical mineralogical palynological geochemical and sedimentological properties of the yenikoy coal deposit and to reconstruct palaeoenvironmental conditions during peat accumulation a total of 9 coal samples collected from the coal seam section are almost entirely composed of xylite rich lithotype and are characterized by low ash yield 7 9 21 1 average 13 6 on dry basis and high total s contents 1 0 3 7 average 2 2 on dry basis the macroscopic features maceral composition and coal facies suggest that the peat was accumulated under mesotrophic anoxic conditions and the peat forming vegetation consisted mainly of arboreal species e g cupressaceae ulmus carya zelkova alnus pterocarya and quercus the low hi values of the analysed samples are presumably related to presence of xylite rich lithotype rather than the dominance of herbaceous plant and or low preservation of organic matter in the palaeomire even though relatively b enrichments high total s contents and weak anomalies of some rey e g y ce and gd in the analysed samples could refer possible sea water influence into palaeomire in the study area during late oligocene the sedimentological and palynological freshwater algaes pediastrum spirogyra and mougeotia data that indicate the palaeomire was located within a delta plain environment where small freshwater lakes and or ponds developed the statistical analysis and sem edx data show the vast majority of elements in the analysed coal samples have inorganic affinity the major elements al k and enriched elements like b v cr hg and u seem to be affiliated with aluminosilicate minerals whereas fe ni and as have probably sulphide affinity the detrital presences of apatite crystals as detected by sem edx analysis indicate that rey have mainly phosphate affinity in the analysed samples vertical distributions of the elements and ash yields suggest that the detrital input ratio was changeable and controlled some elemental enrichment during peat accumulation these variations could be related to development of and fluvial conditions in the study area which interrupted peat accumulation several times during late oligocene

generation of internal solitary waves by lateral circulation in a stratified estuary abstractinternal solitary waves are commonly observed in the coastal ocean where they are known to contribute to mass transport and turbulent mixing while these waves are often generated by cross isobath barotropic tidal currents novel observations are presented suggesting that internal solitary waves result from along isobath tidal flows over channel shoal bathymetry mooring and ship based velocity temperature and salinity data were collected over a cross channel section in a stratified estuary the data show that ekman forcing on along channel tidal currents drives lateral circulation which interacts with the stratified water over the deep channel to generate a supercritical mode 2 internal lee wave this lee wave propagates onto the shallow shoal and evolves into a group of internal solitary waves of elevation due to nonlinear steepening these observations highlight the potential importance of three dimensionality on the conversion of tidal flow to internal waves in the rotating ocean

boundary layer forcing of a semidiurnal cross channel seiche abstract the outer strait of juan de fuca is a stratified tidal channel about 100 km long 20 km wide and 200 m deep tidal currents of o 0 5 m s 1 occur at both diurnal and semidiurnal periods and there is a pronounced spring neap variation in the stratification due to changes in tidal mixing vertical isotherm excursions of o 50 m have previously been observed along the northern side of the channel that appear to be phase locked to the tidal currents analyses of recent adcp and thermistor chain data confirm the isotherm excursions and find that they are accompanied by distinctive baroclinic structures in the horizontal currents that persist across spring neap cycles and from year to year the authors find that the phase of the semidiurnal signal does not vary along the channel as would be expected of an along channel internal tide instead comparison of the semidiurnal measurements with two dimensional analytical and numerical models indicate that much of the baroclinic structure can be explaine

baroclinic effects on wind driven lateral circulation in chesapeake bay abstractthe 2 month long mooring data were collected in a straight midsection of chesapeake bay to document the lateral circulation driven by along channel winds under upestuary winds the lateral circulation featured a clockwise looking into estuary circulation in the surface layer with lateral ekman forcing as the dominant generation mechanism under downestuary winds however the lateral circulation displayed a structure dependent on the wedderburn number w a counterclockwise circulation at small w and two counterrotating vortices at large w the surface lateral velocity was phase locked to the along channel wind speed analysis of the streamwise vorticity equation showed that the strength and structure of the lateral circulation in this stratified estuary were largely determined by the competition between the tilting of planetary vorticity by along channel currents and lateral baroclinic forcing due to sloping isopycnals under strong downestuary winds the lateral baroclinic forcing offset or

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

fast ground water mixing and basal recharge in an unconfined alluvial aquifer konza lter site northeastern kansas abstract ground water chemistry and water levels at three levels in a well nest were monitored biweekly for two and a half years in a shallow unconfined floodplain aquifer in order to study the dynamics of such shallow aquifers the aquifer in northeastern kansas consists of high porosity low hydraulic conductivity fine grained sediments dominated by silt and bounded by fractured limestone and shale bedrock results show that the aquifer underwent chemical stratification followed by homogenization three times during the study period the length of time between maximum stratification and complete homogenization was 3 5 months the chemical parameters most useful for demonstrating the mixing trends were dissolved nitrate and sulfate higher nitrate concentrations were typical of unsaturated zone water and were sourced from fertilizer applied to the cultivated fields on the floodplain variations in sulfate concentrations are attributed to dissolution of rare gypsum in limestone bedrock and variable evapoconcentration in the unsaturated zone the mixing of three chemically different waters entrained unsaturated zone water water entering the base of the floodplain aquifer and water in residence before each mixing event was simulated the resident water component for each mixing event was a fixed composition based on measured water chemistry in the intermediate part of the aquifer the entrained water composition was calculated using a measured composition of the shallow part of the aquifer and measurements of soil water content in the unsaturated zone the incoming basal water composition and the fractions of each mixing component were fitted to match the measured chemistry at the three levels in the aquifer a conceptual model for this site explains 1 rapid water level rises 2 water chemistry changes at all levels in the aquifer coincident with the water level rises 3 low measured hydraulic conductivity of the valley fill and apparent lack of preferential flow pathways 4 minuscule amounts of unsaturated zone recharge and 5 dissolved oxygen peaks in the saturated zone lagging water level peaks we postulate that rainfall enters fractures in bedrock adjacent to the floodplain this recharge water moves rapidly through the fractured bedrock into the base of the floodplain aquifer the recharge event through the bedrock causes a rapid rise in water level in the floodplain aquifer and the chemistry of the deepest water in the floodplain aquifer changes at that time the rising water also entrains slow moving nitrate rich unsaturated zone water altering the chemistry of water in the shallow part of the aquifer vertical chemical stratification in the aquifer is thus created by the change in water chemistry in the upper and lower parts of the saturated zone as the water level begins to decline the aquifer undergoes mixing that eventually results in homogeneous water chemistry the rise in water level from the recharge event also displaces gas from the unsaturated zone that is then replaced as the water level declines following the recharge event this new oxygen rich vadose zone air equilibrates rapidly with saturated zone water resulting in a dissolved oxygen pulse in the ground water that peaks one half to 2 months after the water level peak this oxygen pulse subsequently declines over a period of 2 6 months

assessing redox zones and seawater intrusion in a coastal aquifer in south korea using hydrogeological chemical and isotopic approaches a shallow 25 m coastal alluvial groundwater system underneath a paddy field in the yangyang area of south korea was investigated to examine the occurrence of redox processes the aquifer is affected by seawater intrusion and is characterized by a highly reducing environment facilitated by high organic matter in the sediments hydrochemical data with 34s and 18o of sulfate were examined for depth specific groundwater from two multilevel samplers that were installed at seaward yy2 and landward yy1 locations shallow groundwater showed distinct patterns of redox zoning evidence of significant bacterial sulfate reduction bsr was observed throughout the nearly entire depths of the two boreholes while at the depths of active seawater intrusion in yy2 conditions suitable for methanogenesis were never reached thus at yy2 the deep zone of intense bsr was overlain by a zone in which methanogenesis occurred in a low sulfate environment in contrast concurrent bsr and methanogenesis in yy1 occurred at depths with high sedimentary organic matter and low dissolved sulfate due to intensive bsr considerable bsr in the groundwater representing trapped seawater in a clay layer had resulted in a very strong increase of 34ssulfate up to 99 9 the inferred sulfur isotopic enrichment factor e for bsr in the lower part of yy2 was 12 3 while e at yy1 was much higher 45 9 in addition the observed trends of 18osulfate at yy1 indicated significant oxygen isotope exchange of sulfate oxygen with ambient water likely because of lower cell specific rates of bsr and higher sulfur isotope fractionation as indicated by the 34s in contrast there was little evidence of oxygen isotope exchange between water and so42 at yy2 this study indicates that in coastal aquifers with sulfate reducing activity 34s and 18o of sulfate can reveal zones of active seawater intrusion and of trapped seawater this study provides an example of the application of sulfur and oxygen isotope data with hydrochemical and hydrogeologic data to interpret complex redox zonation in an organic rich coastal environment

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

a lacustrine record of the early stage of the miocene climatic optimum in central europe from the most basin ohře eger graben czech republic this study reports on a 150 m thick macrofossil barren sequence of siliciclastic sediments from a burdigalian age early miocene freshwater lake the lake was located within an incipient rift system of the most basin in the oh e eger graben which was part of the european cenozoic rift system and had an original area of 1000 km 2 sediments from the hk591 core that cover the entire thickness of the lake deposits and some of the adjacent stratigraphic units were analysed by x ray fluorescence spectroscopy a proxy for element composition and magnetic polarity measurement the element proxies were subjected to frequency analysis which provided estimated sedimentation rates and allowed for sediment dating by magnetostratigraphy and orbital tuning of the age model based on the resulting age model and the known biostratigraphy the lake was present between 17 4 and 16 6 ma which includes the onset of the miocene climatic optimum in the latest early miocene the identification of orbital forcing precession obliquity and short eccentricity cycles confirms the stability of the sedimentary environment of the perennial lake in an underfilled basin the dating allowed the sediment record to be interpreted in the context of the current knowledge of the european climate during that period the stability of the sedimentary environment confirms that precipitation was relatively stable over the period recorded by the sediments

contamination of groundwater under cultivated fields in an arid environment central arava valley israel the purpose of this study is to obtain a better understanding of groundwater contamination processes in an arid environment precipitation of 50 mm year due to cultivation additional aims were to study the fate of n k and other ions along the whole hydrological system including the soil and vadose zone and to compare groundwater in its natural state with contaminated groundwater through the drilling of several wells a combination of physical chemical and isotopic analyses was used to describe the hydrogeological system and the recharge trends of water and salts to the aquifers the results indicate that intensive irrigation and fertilization substantially affected the quantity and quality of groundwater recharge low irrigation efficiency of about 50 contributes approximately 3 5 4 million m 3 year to the hydrological system which corresponds to 0 65 m per year of recharge in the irrigated area by far the

lateral dispersion over the continental shelf analysis of dye release experiments lateral dispersion over the continental shelf was examined using dye studies performed as a part of the coastal mixing and optics experiment four experiments performed at intermediate depths each lasting 2 5 5 days were examined in some cases the dye patches remained fairly homogeneous both vertically and horizontally throughout an experiment in other cases significant patchiness was observed on scales ranging from 2 to 10 m vertically and a few hundred meters to a few kilometers horizontally the observations showed that the dye distributions were significantly influenced by shearing and straining on scales of 5 10 m in the vertical and 1 10 km in the horizontal superimposed on these larger scale distortions were simultaneous increases in the horizontal second moments of the dye patches with corresponding horizontal diffusivities based on a fickian diffusion model of 0 3 4 9 m 2 s 1 analysis of the dye data in concert with shear estimates from shipboard acoustic doppler current profiler observations showed that the existing paradigms of shear dispersion and dispersion by interleaving water masses cannot account for the observed diffusive spreading of the dye patches this result suggests that some other mechanisms provided an additional diffusivity of order 0 2 4 6 m 2 s 1 an alternative mechanism dispersion by vortical motions caused by the relaxation of diapycnal mixing events may explain the observed dispersion in some cases

sea level changes an integrated approach sea level changes an integrated approach in october 1985 sepm sponsored a four day conference entitled sea level changes an integrated approach the purpose of the conference was to provide a forum for an interdisciplinary exchange of ideas on sea level changes and to provide an opportunity for integrating various types of evidence in approaching unresolved issues the conference was successful in bringing together scientists from industry academia and government representing all of the major geosciences disciplines presentations of many new papers plus significant releases of data that were previously held proprietary provided fertile ground for discussion this much cited volume represents the best of the material presented at the conference includes the early vail chart

estimation of the water balance of alluvial aquifers in region of high isotopic contrast an example from southeastern france the much contrasted orographic and climatic characters of southeastern france serve to establish a hydrological balance of the porous aquifers in the region comparing a regional average gradient of 18o content versus elevation which was calculated on low water period karst waters content with a 10 5 average d of alpine rivers an estimate of the percentages brought to these aquifers is proposed under the form of an abacus it appears that the main groundwaters of the var the durance and the rhone are fed by an average of 20 30 of provencal underground contribution and 70 80 shallow contribution from the alpine rivers these figures reveal that local supplies range between 25 and 10 of the average yearly discharge flowing in the porous and shallow aquifers

organic facies and depositional palaeoenvironment of lignites from rio maior basin portugal abstract the rio maior basin portugal is a tectonic depression filled by a pliocene sequence that comprises from floor to roof i kaoliniferous fine sands ii diatomites and lignites iii recent deposits of sandstone and clay the diatomites and lignites form a small dissimetric syncline with alternating seams ten lignite seams were identified and named from floor to roof as f e d c 2 c 1 c b a a and a seams a d e and f are considered to be the main seams the organic fraction consists mainly of macerals of the huminite group with small percentages of inertinite and liptinite groups however the petrographic composition of each seam is distinct particularly with regards to macerals of the huminite and liptinite groups calculation of petrographic indices permitted to plot the coals in facies and palaeoenvironment diagrams five facies have been defined i aquatic ii herbaceous swamp iii mixed swamp with forest and herbaceous vegetation vi forest swamp wetter and v forest swamp drier these lignites are humic coals formed from organic matter of terrestrial origin the peat biomass at the origin of these coals formed from a very diverse vegetation comprising gymnosperms and angiosperms in seams f and occasionally in seams e and d botryococcus algae have also contributed to the biomass peat deposition corresponded to a rheotrophic hydrological regime the water level always remained above the topographic surface of the basin nevertheless during the deposition of seam a in the northern part of the basin the water level was slightly below the topographic surface the organic matter was preserved in anaeorobic conditions

comparing maceral ratios from tropical peatlands with assumptions from coal studies do classic coal petrographic interpretation methods have to be discarded petrographic investigations of tropical peat deposits from the tasek bera basin malaysia show that petrographic methods can contribute valuable information about paleoecological settings of mire deposits comparing modern peat forming environments and the pre maceral composition of peat samples allows the reconstruction of paleoecological conditions such as floral composition fires microbial activity etc and gives insight into paleodepositional environments in the past maceral ratios of coals have been used to interpret paleodepositional settings of coal deposits such a procedure assumes that coal texture and coal maceral composition are dictated solely by the depositional environment and thus different depositional environments should be clearly discriminated based on maceral ratios in the modern peat deposits of tasek bera divergent petrographic results occur in similar depositional environments hence poor correlation occurs between the petrography the degree of decomposition and the depositional environment furthermore from the time of peat deposition peat is subject to considerable alteration during subsequent diagenesis preservation of structured and strongly altered material such as inertinite gelified material or funginite is favoured and results in biased coal maceral compositions because maceral indexes in modern peat studies are of little utility in the reconstruction of paleoenvironmental settings it follows that coal maceral indexes should not be utilized in the future to interpret paleodepositional environments of coals

axial convergence in a well mixed estuary abstract transverse secondary circulations involving surface convergence observed in a well mixed estuary in north wales are made visible by the collection of surface material along an axial line which extends continuously for many kilometres through the estuary the circulation and axial convergence however are seen only during the flood phase of the tide and no similar behaviour has been observed during the ebb phase convergent circulations in the estuary are associated with small but steady transverse density gradients in the cross section produced by non uniform advection of the longitudinal gradient through the channel a diagnostic model using measured mean distributions of cross sectional density indicates surface transverse velocities 0 1 ms 1 similar to those observed in the estuary the model further predicts appreciable transverse divergent currents at a fractional depth of 0 75 a prediction which has been tested in the estuary using a vertical array of accurately resolving current direction indicators

internal solitary waves in the warm pool of the western equatorial pacific abstract during the spring tides of late november 1992 early january and early february 1993 solitary internal wave packets were observed at 2 s 156 15 e in the western equatorial pacific apparently generated in the nuguria island group 3 s 153 e the waves propagate northeastward at 2 4 2 8 m s 1 appearing in fixed phase with the underlying semidiurnal baroclinic tide the initial solitary wave crests have downward displacements in excess of 60 m and peak velocities greater than 80 cm s 1 groups of 1 3 crests are observed with vertical structure resembling a first mode internal wave and horizontal variability consistent with third order comb kdv solitons many of the packets exhibit an overall organization reminiscent of undular bores this borelike behavior is confined primarily to the upper 70 m not sharing the mode one dependency of the crests the solitons displace the ambient equatorial currents including the equatorial undercurrent both vertically 80 m and laterally 1 2 km with l

generation and propagation of internal tides and solitary waves at the shelf edge of the bay of biscay high frequency mooring data were collected near the northern shelf edge of the bay of biscay to investigate the generation and propagation of internal tides and internal solitary waves isws during spring tide strong nonlinear internal tides and large amplitude isws are observed every semi diurnal tidal period while onshore propagation was expected since the mooring is located shoreward of the maximum internal tidal generation location both onshore and seaward traveling internal tides are identified within a tidal period at spring tide three isw packets are observed like internal tides different isw packets have opposite seaward and shoreward propagating direction based on realistic hydrostatic hycom simulations it is suggested that advection by the barotropic tide affects wave generation and propagation significantly and is essential for the seaward traveling internal tides to appear shoreward of their generation location a two layer idealized non hydrostatic model derived by gerkema 1996 further confirms the effect of advection on the generation and propagation of internal tides moreover the two layer model reproduces one seaward propagating isw packet and one shoreward propagating isw packet indicating that the offshore and onshore traveling isws are excited by nonlinear steepening of the seaward and shoreward traveling internal tides respectively this article is protected by copyright all rights reserved

evolution of a shoaling internal solitary wavetrain 1 field observations of an internal solitary wavetrain impacting a shoaling bottom are presented measurements of the spatio temporal characteristics of the shoaling waves are given as well as estimations of the mixing they may have caused upon impact the observations are discussed in the context of numerical simulations laboratory experiments and hypotheses recently raised on the origin and evolution of internal solitary waves in coastal environments

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

climatic vs tectonic controls on peat accretion in non marine setting an example from the žacleř formation yeadonian bolsovian in the intra sudetic basin czech republic abstract the acle coalfield in the western part of the intra sudetic basin is an example of coal accumulation in an alluvial valley deposited under a long term 3 m y stable tectonic regime with climatic oscillations possibly operating on several time scales the resulting sedimentary record about 600 m thick encompasses about 60 coal bearing cycles formed in a relatively small and localized part of the valley whereas elsewhere a higher clastic input and or lower rate of subsidence resulted in deposition of strata with very little coal available data suggest that tectonics produced accommodation for sediments and via changes in topography and or size of the source area affected the volume and dispersal patterns of clastic material transported to the depocentre areas with long term tectonic stability were suitable places for recognition of climatic signals in the sedimentary record modified by the intensity of local clastic input climatic fluctuations generated coal bearing cycles probably through a variable intensity of precipitation which affected the density of vegetation cover across the landscape along with evaporation and groundwater table these factors influenced the intensity of chemical weathering and hence regulated the volume and composition of clastics delivered to the depocentre this in turn resulted in alternation of short periods of bedload dominated deposition during the seasonally dry part of the cycle with periods of dominantly suspended load and organic peat deposition during the more humid everwet part of the cycle estimated duration of the basic cycles 46 k y approximates the orbitally driven axial tilt cyclicity basic cycles are arranged into two larger scale cyclic patterns lasting for 270 k y and 1 5 m y respectively which broadly correspond with the timing of glacial maxima and minima inferred from high latitude glacial deposits of gondwanan basins all the coals of the acle coalfield display similar petrographic composition dominated by collotelinite and field observations as well as detailed petrographic study show that they formed in planar rheotrophic peat swamps where long lasting peat accretion was episodically interrupted only by major floods on a century to millennial scale

effect of relative lake level changes in mire lake system on the petrographic and floristic compositions of a coal seam in the most basin miocene czech republic abstract exposures in the bilina opencast mine provide a direct evidence that the 3 5 m thick upper bench of the main seam in the most basin passes over a distance of about a kilometre into a hundred metres thick equivalent of clastic deltaic sediments with gilbert type mouth bars and thus clearly corroborates the co existence of lacustrine delta mire system deposition of the delta and the upper bench of the main seam were affected by five short term lacustrine incursions possibly related to tectonic subsidence before final lacustrine transgression took place between the temporary lacustrine incursions delta mouth bars prograded into an extensive mire being separated only by a shallow compaction lake along mouth bars foreland however most clastics introduced from delta were caught by dense vegetation in a narrow proximal zone of mire and did not affect more distal parts of relatively dry woodland mire with water table fluctuating around the surface it is therefore characterised by low ash yield and increased resinite fusinite and inertodetrinite contents palynological data indicate that the peat forming vegetation of the upper bench of the main seam was dominated by taxodiaceae glyptostrobus athrotaxis and calamus palm accompanied by paludal species of the family pinaceae and rich undergrowth of ferns and vaccinium type ericaceae progradation of delta mouth bars to the proximity of the study section is documented by increasing proportion of allochthonous elements produced by plants colonizing the flood plain and delta plain areas nyssa taxodium parrotia ulmus pyramidalis and comptonia pinus oviformis associations in contrast during periods of temporary lacustrine transgressions the mire was replaced by open water environment which favoured deposition of clay rich coals or partings 30 of ash yield of the flooding horizons in spite of fact that delta body retreated to the basin margin and the clastics were introduced from a larger distance rare palynomorphs indicate only sparse vegetation cover of aquatic plants during this time clay content seems to be the best indicator of the water level fluctuations facies indices e g tpi and gi show only poor correlation to hydrological and floristic changes detected in the mire lake system

the influence of lateral advection on the residual estuarine circulation a numerical modeling study of the hudson river estuary abstract in most estuarine systems it is assumed that the dominant along channel momentum balance is between the integrated pressure gradient and bed stress scaling the amplitude of the estuarine circulation based on this balance has been shown to have predictive skill however a number of authors recently highlighted important nonlinear processes that contribute to the subtidal dynamics at leading order in this study a previously validated numerical model of the hudson river estuary is used to examine the forces driving the residual estuarine circulation and to test the predictive skill of two linear scaling relationships results demonstrate that the nonlinear advective acceleration terms contribute to the subtidal along channel momentum balance at leading order the contribution of these nonlinear terms is driven largely by secondary lateral flows under a range of forcing conditions in the model runs the advective acceleration terms nearly always act in concert with the baroclinic pressure gradie

distribution of oxygen and hydrogen isotopes in shallow groundwaters from southern india influence of a dual monsoon system oxygen and hydrogen isotopic investigation of groundwater and river water samples from the southern indian peninsula was undertaken to characterise the isotopic nature of the near surface water sources and provide basic framework for future hydrological studies it is assumed that the shallow groundwater retains the isotopic signature of the local precipitation averaged over a few tens of years except in a few cases where the same gets modified by post precipitation evaporation and or recharge contribution from surface water bodies therefore isotopic character of the groundwater can in principle be used to determine the relative influence of the different vapour sources contributing to the local regional precipitation and to characterise the modifications before groundwater recharge in the present context vapour sources for two rainy seasons namely southwest sw and northeast ne monsoon are respectively the indian ocean arabian sea and the asian continental sources together with the bay of bengal this study shows that i the regions dominated by ne monsoon have distinctly depleted isotopic composition compared to those dominated by sw monsoon ii the 18o d regression line slope of 6 in the east coast region is lower than that expected for local precipitation suggesting secondary evaporation iii the orography of the western ghats hill ranges plays a significant role in controlling the isotopic distribution along the west coast region iv the low d excess values in most part of study area indicate secondary evaporation v the high d excess values over the deccan plateau region in the nw part of the study area suggest admixture of recycled moisture with the inflowing oceanic vapour

the generation and trapping of solitary waves over topography observations of tidal flow over a sill show that upstream solitary wave generation occurred in conjunction with the downstream movement of a streamline bifurcation over the obstacle crest solitary waves appeared upstream of the bifurcation riding on the surface stratification shear flow instabilities on the plunging interface were also evident and may contribute to wave generation through subharmonic interaction nonlinear waves generated downstream of an internal control became trapped in the supercritical flow

the geology petrography and palynology of tertiary coals from the eureka sound group at strathcona fiord and bache peninsula ellesmere island arctic canada abstract coal seams of substantial thicknesses and lateral continuity are developed in the expedition and iceberg bay formations at strathcona fiord and in the expedition formation at bache peninsula the coals are lignite subbituminous in rank and have low to moderate sulphur and variable ash contents at strathcona fiord resources have been estimated to be in the order of 1 billion tonnes whereas at bache peninsula estimated resources are 100 million tonnes the coals at strathcona fiord are characterized by the dominance of wood derived macerals of the humotelinite group whereas at bache peninsula the coals have high amounts of detrital macerals humodetrinite and also have significant amounts of inertinite macerals pollen and spore assemblages in coals from the iceberg bay formation at strathcona fiord are dominated by taxodiaceace pollen with less and variable amounts of pinaceae pollen pteridophyte spores and angiosperm pollen the pollen and spore assemblages indicate a late paleocene early eocene age of the iceberg bay formation coals the expedition formation coals at bache peninsula have in general a somewhat less diverse pollen and spore assemblage and show a larger input of fern and sphagnum spores the pollen and spore assemblages in expedition formation coals at bache peninsula are indicative of early paleocene age the depositional environment for iceberg bay formation coals at strathcona fiord is that of a forested swamp which formed on a broad coastal plain at bache peninsula peats formed in broad valleys in which a fluviatile lacustrine environment of deposition prevailed the mires were likely less forested than at strathcona fiord as indicated by the abundance of ferns and sphagnum spores and the very low content of wood derived macerals of the humotelinite group the pollen assemblages in both expidition and iceberg bay formation coals indicate a temperate climate and moderate precipitation during peat accumulation

pliocene lignites from apofysis mine amynteo basin northwestern greece petrographical characteristics and depositional environment coal petrological investigation along with proximate and elemental analyses were undertaken to determine the petrographic characteristics of the apofysis lignites amynteo basin northwestern greece and their depositional environment eight samples representing different lignite beds of the apofysis deposit were collected from a borehole the apofysis lignites have an eu ulminite b reflectance of rr 0 22 and in terms of lithotype belong to matrix soft brown coals huminite is the most abundant maceral group and consists mostly of humodetrinite inertinite has relatively low percentages whereas liptinite concentrations are low in the lower lignite beds and higher in the upper ones ternary plots and facies indices were employed in order to investigate the palaeoenvironment the depositional environment of the apofysis lignites is not definitely ascribed to a forest swamp or a reed marsh environment the high ash content of the analysed samples is a clear indication of a topogenous setting low tissue preservation index tpi and high gelification index gi values are observed high alkalinity and strongly reducing conditions may be inferred from the presence of syngenetic framboidal pyrite the low tpi values which indicate high bacterial activity and thus high ph conditions and the preservation of gastropod shells and chlorophyllinite high gi indicates a constant influx of calcium rich waters into the coal swamp the apofysis lignite deposit may be interpreted to be autochthonous to hypoautochthonous the peat accumulation was governed by a high groundwater level wet telmatic to limno telmatic facies and a moderate subsidence rate

internal solitons on the pycnocline generation propagation and shoaling and breaking over a slope in part 1 a study is made of the internal solitary wave on the pycnocline of a continuously stratified fluid a korteweg de vries kdv equation for the interfacial displacement is developed following benney s method for long nonlinear waves experiments were conducted in a long wave tank with the pycnocline at several different depths below the free surface while keeping the total depth approximately constant a step like pool of light water trapped behind a sliding gate served as the initial disturbance condition the number of solitons generated was verified to satisfy the prediction of inverse scattering theory the fully developed soliton was found to satisfy the kdv theory for all ratios of upper layer thickness to total depth in part 2 of this study we investigate experimentally the evolution and breaking of an internal solitary wave as it shoals on a sloping bottom connecting the deeper region where the waves were generated to a shallower shelf region it is found through quantitative measurements that the onset of wave breaking was governed by shear instability which was initiated when the local gradient richardson number became less than the internal solitary wave of depression was found to steepen at the back of the wave before breaking in contrast with waves of elevation two slopes were used with ratios 1 16 and 1 9 and the fluid was a boussinesq fluid with weak stratification using brine solutions

paleoenvironmental interpretation of the amynteon ptolemaida lignite deposit in northern greece based on its petrographic composition abstract the objective of this study was to reconstruct the paleoenviromnent during formation of the deposit at amynteon ptolemaida based mainly on its petrographic but also supported by its paleobotanic character and fossils found in the lignite beds themselves the deposit of amynteon occurs in the northern part of the elongated basin of ptolemaida amynteon the type of lignite formation is in general terms similar to the deposit of ptolemaida and the lignite is present in the pleistocene strata of the basin the alternating nature of lignite and interburden is an important characteristic of the deposit in this study we selected 20 samples of lignite from a representative drillhole namely b 258 in order to discern its petrography optical microscopy showed that the huminite group macerals are dominant ranging from 42 5 to 95 3 humotelinite is present in low to high quantities 12 0 79 5 followed closely by humodetrinite humocollinite is present in very small amounts in addition macerals of the liptinite and inertinite groups are found in small concentrations with a few exceptions a number of indices such as gelification index gi vegetation index vi groundwater index gwi tissue preservation index tpi and their ratios e g vi gwi tpi gi were used to reconstruct the conditions prevailing during peat formation the results indicate that the paleoenvironment was mainly limnic at the initial stages and transitioned to limnotelmatic with occasional rheotrophic conditions the organic matter responsible for lignite formation developed mainly in a forested swamp environment with occasional transitions either towards a wet limnic open water or a drier telmatic environment

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

generation of internal lee waves by lateral circulation in a coastal plain estuary abstractrecent mooring observations at a cross channel section in chesapeake bay showed that internal solitary waves regularly appeared during certain phases of a tidal cycle and propagated from th

petrographic characteristics of coal from the lati formation tarakan basin east kalimantan indonesia the present paper entails the petrographic characterization on limited coal samples drawn from the tarakan basin eastern kalimantan indonesia these coals contain a high concentration of huminite which in turn is dominated by telohuminite as a result of telohuminite content they have high gi and tpi values they contain low concentrations of liptinite and inertinite macerals the dominant microlithotype is vitrite based on the macerals and microlithotypes of these coals their paleodepositional environment has been reconstructed accordingly it is deciphered that these coals have originated under telmatic condition there was predominance of wood derived tissues and increased subsidence rate prevailed in the basin moreover during the time of their evolution there were alternate phases of oxic and anoxic moor conditions with intermittent moderate to high flooding in the basin

geoelectric resistivity sounding of riverside alluvial aquifer in an agricultural area at buyeo geum river watershed korea an application to groundwater contamination study twenty profiles of vertical electric soundings ves were obtained in a riverside alluvium at the buyeo area south korea to examine the variations of subsurface geology and associated groundwater chemistry the combination of the ves data with the borehole data provided useful information on subsurface hydrogeologic conditions the vestige of an ancient river channel e g oxbow lake was identified on the resistivity profiles by the lateral continuation of a near surface perched aquifer parallel to the river such a perched aquifer is typically developed in the area with a clay rich silty surface alluvium which prohibits the infiltration of oxygen therefore groundwater below the oxbow lake shows a very low nitrate concentration and eh values under the strong anoxic condition the distribution of water resistivity is correlated with that of measured total dissolved solids concentration in groundwater while the earth resistivity of the aquifer shows a significant spatial variation it is interpreted that the earth resistivity of the aquifer is mainly controlled by the soil type rather than by the water chemistry in the study area

internal hydraulic flows on the continental shelf high drag states over a small bank observations of currents hydrography and turbulence provide unambiguous evidence for hydraulic control of flow over an isolated three dimensional topographic feature on oregon s continental shelf the flow becomes critical at the crest of the bank forming a strong supercritical downslope flow in the lower layer farther downstream internal hydraulic jumps form as the bottom flow becomes subcritical as a consequence turbulence is greatly enhanced in the bottom boundary layer in the sheared interface above the swiftly flowing bottom current and in the internal hydraulic jump the dissipation rate of turbulent energy is consistent with the mean energy removal rate for a hydraulic jump in an idealized two layer flow this enhanced turbulence constitutes a high drag state of the flow in which the form drag introduced by the topography exerts significant influence on the flow around it and mixing is increased 102 103 times the background values

petrology and organic geochemistry of the lower miocene lacustrine sediments most basin eger graben czech republic abstract thirty samples of the lacustrine sediments from three localities of the most basin including coal samples were studied by petrological and organic geochemical methods the consistent results indicate the relatively stable surface development of the sediments in the environment of the holesice lom and osek members biological material with contribution of microbial activity participated in the storing which led to the formation of clayey coal in the results of the chemical composition dominated sesqui diand triterpene compounds completely different sediments of libkovice member contained low proportions of small organic particles dispersed in the sediment in the extracts of these samples prevailed hopanes perylene and sulphur after the action of microorganisms the base of the organic fraction also formed remains of terrestrial plants and liptinite macerals especially alginite liptodetrinite and bituminite that are typical for lacustrine sediments

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

groundwater replenishment analysis by using natural isotopes in ejina basin northwestern china the ejina basin underlying complex aquifers is located in the lower reaches of the heihe river with an arid climate and 40 mm mean annual precipitation as the balance of the natural ecosystem in the ejina basin is fragile and easily upset it is very important to estimate and rationally use the limited groundwater resources to maintain the balance water samples were collected from the heihe river and wells for chemical and isotopic measurements across the basin the piper diagram gives two main types of hydrochemical features against the background of the regional geology combining isotope 18o tritium and chemical analysis with groundwater flows indicated by a shallow groundwater level contour map different kinds of groundwater sources and ways to replenish groundwater were discovered north of the study area are artesian wells that are replenished by the mountainous area at the boundary between china and mongolia replenishment for most of the groundwater resources of the gurinai oasis comes from the heihe river seepage flow of the highly conductive paleochannel not from the badain jaran desert as indicated by tds and tritium analysis the different groundwater ages which are younger than 35 years were approximately estimated by radioactive isotope tritium t by such efforts groundwater resources can be effectively evaluated with the engineering impact of the heihe river project

climatic instability before the miocene climatic optimum reflected in a central european lacustrine record from the most basin in the czech republic abstract the work investigates the extensive freshwater lacustrine deposits of the most formation which formed in the period between 17 7 ma and ca 15 9 ma in order to describe climate changes just before the miocene climatic optimum mco the most basin an incipient rift within the european cenozoic rift system exhibited a sedimentary environment that was sufficiently stable to preserve orbital signatures of environmental changes changes in the mineral composition of the sediments were characterised in terms of variations in their elemental composition particularly their al si and k ti element ratios and fe sr and zr elemental abundances which were efficiently obtained using x ray fluorescence spectroscopy with a density of 3 4 samples per metre of core approximately 15 20 samples per precession cycle the sediments are distinguished by the presence of distinct and correlated horizons 1 10 cm thick containing sr ba rich crandallite a mineral from the aluminium phosphate sulphate aps group chemo magneto and cyclostratigraphy were used to correlate eight cores with lengths up to 240 m and to date the sediment discrepancies at scales of up to two precession cycles each ca 20 kyr typically 4 m per cycle were observed the primary age model was based on magnetic polarity analysis 5 reversals and later refined at the metre scale using cyclostratigraphy we interpret the onset of the basin wide lacustrine phase in the most basin as being a consequence of the enhanced input of fluvial clastic sediment to the former peat swamps during the high eccentricity period at 17 7 17 55 ma i e immediately after the initial decay of the east antarctic ice sheet according to levy et al 2016 the most important environmental change recorded by the lacustrine interval in the most basin occurred at 16 44 ma during an eccentricity maximum and is nearly coeval with further shrinkage of the east antarctic ice sheet the second stage of monotonous lacustrine deposition which exhibited enhanced precession controlled compositional variability in 16 1 16 0 ma witnessed the onset of the mco sediments younger than 15 9 ma are missing due to erosional removal after subsequent basin inversion the sediments of the most formation represent an archive of environmental change in central europe during the early stages of the mco and have a temporal resolution ca 5 kyr

sediment resuspension and mixing by resonantly generated internal solitary waves the observation of internal solitary waves isws propagating upstream along a strongly stratified bottom layer on the california shelf is reported an increased concentration of particulates in the water column accompanies the passage of these isw packets the estimated local richardson number in the bottom vicinity is around 1 4 and a vertical coefficient of eddy diffusivity of order 1022 m2 s21 is associated with the upstream propagating leading isw the leading isw gave rise to reversed flow in an 8 m layer above the bottom it is argued that the upstream propagating isws were generated by resonant flow over bottom topography internal waves generated in this way seem to be frequent in the record of a month long experiment model results suggest that the isws can carry up to 73 of such generated long wave energy the ocean conditions at the site are similar to those of other coastal sites which suggests that the phenomenon described here may be common

a logging correlation scheme for the main coal seam of the north bohemian brown coal basin and the implications for the palaeogeographical development of the basin

modeling the lateral circulation in straight stratified estuaries the dynamics of lateral circulation in an idealized straight estuary under varying stratification conditions is investigated using a three dimensional hydrostatic primitive equation model in order to determine the importance of lateral circulation to the momentum budget within the estuary for all model runs lateral circulation is about 4 times as strong during flood tides as during ebbs this flood ebb asymmetry is due to a feedback between the lateral circulation and the along channel tidal currents as well as to time varying stratification over a tidal cycle as the stratification is increased the lateral circulation is significantly reduced because of the adverse pressure gradient set up by isopycnals being tilted by the lateral flow itself when rotation is included a timedependent cross channel ekman circulation is driven and the tidally averaged bottom lateral circulation is enhanced toward the right bank when looking toward the ocean in the northern hemisphere this asymmetry in the tidally averaged bottom lateral circulation may lead to asymmetric sediment transport leading to asymmetric channel profiles in straight estuaries for the weakly stratified model run advection due to lateral currents is a dominant term in both the along channel and cross channel momentum equations over a tidal cycle and for the tidally averaged momentum equations in the tidally averaged along channel momentum equation lateral advection acts as a driving term for the estuarine exchange flow and can be larger than the along channel pressure gradient therefore it should not be ignored when estimating momentum budgets in estuaries

combined use of tracer approach and numerical simulation to estimate groundwater recharge in an alluvial aquifer system a case study of nasunogahara area central japan summary in this study we simulate the spatial and temporal distribution of groundwater recharge in an alluvial aquifer system in the nasunogahara area of japan natural stable isotopes 18 o d were considered as additional calibration targets in a numerical model the reliability of the model outputs was further validated by comparing the results from the numerical simulation and an independent tracer approach the results indicated that the calibrated model can effectively simulate the spatial and temporal characteristics of the contribution ratios of recharge sources to groundwater in the nasunogahara area however the tracer approach i e end member mixing analysis provided more reliable results at point scale particularly for the estimated contribution ratios of paddy field water the precipitation in the nasunogahara area is the major recharge source its mean contribution ratio is 58 for a one year period over the entire alluvial fan river seepage is significant in the upstream area of the alluvial fan and the contribution ratio of river waters along the river channels in the upstream area increases during the wet season paddy field water is a highly important recharge source in the midstream and downstream areas of the alluvial fan and the contribution ratio of paddy field water obviously increases from dry season to wet season because of irrigation this study demonstrates that combined use of the tracer approach and numerical simulation with stable isotopes as additional calibration targets can eliminate their respective limitations and can assist in better understanding the groundwater recharge mechanism in alluvial aquifer systems

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

observations of highly nonlinear internal solitons over the continental shelf surface disturbances caused by strong near surface internal waves are widely seen in coastal regions as bands of slick and rough water propagating shoreward these surface slicks are typically manifestations of optical and radar backscatter properties above internal solitons and have strong surface current pulses associated with them during a recent experiment studying coastal internal waves extremely strong solitary internal wave packets were observed over a three week period on a very shallow and strongly stratified pycnocline off northern oregon during periods of strongest tidal forcing solitons were consistently observed on the leading edge of a semidiurnal internal tide bore with pycnocline displacements up to 25m downward from a 7m initial depth in the first few solitons the extreme nonlinearity of these internal waves is believed to be unique in ocean observations this note characterizes these highly nonlinear solitary internal waves siw and presents a second order kdv model which reproduces the form of the displacements and the small change in soliton width with amplitude predicted by this model

physical and biological processes underlying the sudden surface appearance of a red tide in the nearshore the sudden appearance at the surface of an alongshore parallel band of red tide near huntington beach california is described in high spatial and temporal resolution using novel instrumentation including a global positioning system tracked jet ski the scale of the surface chlorophyll a chl a band was small 200 m crossshore and ephemeral 3 h compared with the subsurface extent of the red tide 2 km 7 d the red tide was dominated by the regionally common dinoflagellate lingulodinium polyedrum f stein and had developed as a subsurface chl a layer during the 7 d prior to the surface appearance a few hours before the surface appearance a subsurface patch of elevated chl a chl a 30 m gl 21 was observed in 13 m total depth in the trough of a shoreward propagating internal wave consistent with dinoflagellate vertical swimming interacting with the internal wave driven convergence internal wave breaking induced vertical mixing in 8 m water depth vertically spread the chl a patch to the surface creating the alongshore surface band 500 m from shore both the subsurface chl a patch and the surface chl a band were prevented from entering the surf zone by a density barrier of warm water adjacent to the beach these high resolution observations emphasize the role of nearshore physical dynamics in controlling the duration and intensity of red tide exposure to coastal habitats

upstream internal hydraulic jumps abstract in stratified tidal flow over a sill the character of the upstream response is determined by a froude number fs based on the stratification near the surface this is distinguished from the froude number governing the response in the neighborhood of the sill crest which is based on the weak density step associated with a flow bifurcation for moderate values of fs the upstream response consists of nonlinear waves or a weak undular bore for larger values of fs a strong quasi stationary internal hydraulic jump dominates the upstream response at sufficiently large values of fs the upstream bore is swept downstream and lost acoustic backscatter and velocity data are presented for the case of a strong internal bore or gravity current in a tidally modulated sill flow numerical simulations with varying near surface stratification are presented to illustrate the upstream responses at different values of fs the theory of two layer hydraulic flows is invoked to account for the development of the

groundwater geochemistry of a nitrate contaminated agricultural site groundwater samples were collected from several soil depths down to 50 m below soil surface to investigate vertical profiles of no3 and hydrogeochemical characteristics of the experimental site the experimental site is located in the shimabara city nagasaki japan where nitrate contamination in groundwater is severe due to intensive agricultural production a transition zone regarding dissolved ions was found between specific depths caused by differences in the permeability of soil layers though no3 concentration decreased significantly in the transition zone the entire soil depth exceeded permissible levels 50 mg l 1 for drinking purposes comparing the temporal no3 fluctuation above the transition zone with that of the below distinct fluctuations were observed depending on sampling campaign high rainfall amounts typically lead to initial decrease in no3 concentration for the shallow groundwater after some time however increase in no3 concentration occurred due to leaching of accumulated no3 in the soil matrix this indicated that temporal no3 fluctuation is mainly controlled by natural impact and occurring crop system results of principal component analysis suggested that application of chemical fertilizers nh4 2so4 nh4no3 and kcl dissolution of minerals feldspar calcite and dolomite and ion exchange are the predominant factors resulting in the observed vertical groundwater chemistry the relative magnitude of these three principal component scores changed across the transition zone below the transition zone groundwater geochemistry reflected application of nh4no3 and kcl fertilizer and dissolution of albite and orthoclase less

comparison of genesis and geostatistical methods for characterizing the heterogeneity of alluvial media groundwater flow and transport simulations abstract we describe a new method for generating the sediment heterogeneity of alluvial deposits based on a genesis model which mimics some of the hydraulic rules by which meandering or braided streams deposit or erode sediments the new model is described and compared with other approaches and is then applied to a 5 4 1 4 km 2 reach of the aube river upstream of paris the model is based on data obtained from a single cross section of the alluvial plain with 44 auger holes along the 1 4 km stretch of the plain as the model describes the sediment facies we assign to each facies an assumed hydraulic conductivity flow and transport simulations are then made with the commonly used code modflow in order to compare the results with simulations based on other descriptions of heterogeneous media we then use classical geostatistical tools indicator simulations to generate alternative images of the same medium based on the same initial data and the same assumptions on the hydraulic conductivity of each facies finally an equivalent uniform medium obtained through permeability upscaling is also generated comparing these three approaches on the basis of the flow and transport results we show the intrinsic capacity of the new model to generate more realistic flow and transport processes in heterogeneous alluvial media where permeability barriers and buried channels dominate the spatial distribution of heterogeneities

identification of groundwater recharge sources and processes in a heterogeneous alluvial aquifer results from multi level monitoring of hydrochemistry and environmental isotopes in a riverside agricultural area in korea we evaluated sources and pathways of groundwater recharge for a heterogeneous alluvial aquifer beneath an agricultural field based on multi level monitoring of hydrochemistry and environmental isotopes of a riverside groundwater system at buyeo korea two distinct groundwater zones were identified with depth 1 a shallow oxic groundwater zone characterized by elevated concentrations of no3 and 2 a deeper 10 14 m from the ground surface sub oxic groundwater zone with high concentrations of dissolved fe silica and hco3 but little nitrate the change of redox zones occurred at a depth where the aquifer sediments change from an upper sandy stratum to a silty stratum with mud caps the 18o and 2h values of groundwater were also different between the two zones hydrochemical and 18o 2h data of oxic groundwater are similar to those of soil water this illustrates that recharge of oxic groundwater mainly occurs through direct infiltration of rain and irrigation water in the sandy soil area where vegetable cropping with abundant fertilizer use is predominant oxic groundwater is therefore severely contaminated by agrochemical pollutants such as nitrate in contrast deeper sub oxic groundwater contains only small amounts of dissolved oxygen do and no3 the 3h contents and elevated silica concentrations in sub oxic groundwater indicate a somewhat longer mean residence time of groundwater within this part of the aquifer sub oxic groundwater was also characterized by higher 18o and 2h values and lower d excess values indicating significant evaporation during recharge we suggest that recharge of sub oxic groundwater occurs in the areas of paddy rice fields where standing irrigation and rain water are affected by strong evaporation and that reducing conditions develop during subsequent sub surface infiltration this study illustrates the existence of two groundwater bodies with different recharge processes within an alluvial aquifer copyright 2009 john wiley sons ltd

topographic effect on oblique internal wave wave interactions based on a variable coefficient kadomtsev petviashvili kp equation the topographic effect on the wave interactions between two oblique internal solitary waves is investigated in the absence of rotation and background shear the model set up featuring idealised shoaling topography and continuous stratification is motivated by the large expanse of continental shelf in the south china sea when the bottom is flat the evolution of an initial wave consisting of two branches of internal solitary waves can be categorised into six patterns depending on the respective amplitudes and the oblique angles measured counterclockwise from the transverse axis using theoretical multi soliton solutions of the constant coefficient kp equation we select three observed patterns and examine each of them in detail both analytically and numerically the effect of shoaling topography leads to a complicated structure of the leading waves and the emergence of two types of trailing wave trains further the case when the along crest width is short compared with the transverse domain of interest is examined and it is found that although the topographic effect can still modulate the wave field the spreading effect in the transverse direction is dominant

microfacies and depositional environment of tertiary tanjung enim low rank coal south sumatra basin indonesia abstract the south sumatra basin is among the most important coal producing basins in indonesia results of an organic petrography study on coals from tanjung enim south sumatra basin are reported the studied low rank coals have a mean random huminite reflectance between 0 35 and 0 46 and are dominated by huminite 34 6 94 6 vol less abundant are liptinite 4 0 61 4 vol and inertinite 0 2 43 9 vol minerals are found only in small amounts 0 2 vol mostly as iron sulfide based on maceral assemblages the coals can be grouped into five classes 1 humotelinite rich group 2 humodetrinite rich group 3 humocollinite rich group 4 inertinite rich group and 5 humodetrinite liptinite rich group comparing the distribution of maceral assemblages to the maceral or pre maceral assemblages in modern tropical domed peat in indonesia reveals many similarities the basal section of the studied coal seams is represented typically by the humodetrinite liptinite rich group this section might be derived from sapric or fine hemic peat often occurring at the base of modern peats the middle section of the seams is characterized by humotelinite rich and humocollinite rich groups the precursors of these groups were hemic and fine hemic peats the top section of the coal seams is typically represented by the humodetrinite rich or inertinite rich group these groups are the counterparts of fibric peat at the top of the modern peats the sequence of maceral assemblages thus represents the change of topogenous to ombrogenous peat and the development of a raised peat bog a comparison between the result of detailed maceral assemblage analysis and the paleodepositional environment as established from coal maceral ratio calculation indicates that the use of coal maceral ratio diagrams developed for other coal deposits fails to deduce paleo peat development for these young tropical coals in particular mineral distribution and composition should not be neglected in coal facies interpretations

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

near bed solibores over the continental slope in the faeroe shetland channel abstract on two occasions within a 12 day measurement period in the faeroe shetland channel strongly nonlinear wave trains were observed at the sea bed propagating up the continental slope in water depths 450 m the events were separated by a period of 4 days and whilst resembling in appearance a density current running up a slope are termed solibores displaying the properties of both turbulent internal bores and nonlinear internal solitary waves isw each solibore displays a steep leading edge followed by a train of nonlinear waves with amplitudes of o 10 m and periods of 5 20 min wave induced particle velocities are consistent with isw whilst a zone of strong horizontal convergence at the leading edge of the solibores causes the formation of a rotor with flow in the opposite sense to a forward overturning surface wave in both cases upward vertical velocities 10 cm s 1 are immediately followed by a return downward flow of equal magnitude a ctd and microstructure transect conducted during the passage of the first solibore illustrates its behaviour as an up slope intrusion of cold dense water with concurrent rates of turbulent dissipation e of o 10 7 w kg 1 and resulting in short term maximum vertical diffusivities kz of o 10 1 m2 s 1 in the long term however kz 140 days which again indicate intermittency in periods of enhanced sediment flux the solibores are consistent with the results of numerical and laboratory experiments on hydraulic jumps resulting from shoaling isw the influence of the slope is proposed to be the reason for their slightly different forms and effects on sediment transport thus the first solibore propagating directly up the slope is proposed to result from an overturning hydraulic jump caused by kinematic instabilities and which subsequently forms a horizontal density intrusion the second solibore represents a dispersive wave train due its oblique direction of propagation which reduces the effective bottom slope allowing dispersion to balance nonlinear effects and prohibiting overturning

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

structure and generation of turbulence at interfaces strained by internal solitary waves propagating shoreward over the continental shelf abstract detailed observations of the structure within internal solitary waves propagating shoreward over oregon s continental shelf reveal the evolving nature of interfaces as they become unstable and break creating turbulent flow a persistent feature is high acoustic backscatter beginning in the vicinity of the wave trough and continuing through its trailing edge and wake this is demonstrated to be due to enhanced density microstructure increased small scale strain ahead of the wave trough compresses select density interfaces thereby locally increasing stratification this is followed by a sequence of overturning high density microstructure and turbulence at the interface which is coincident with the high acoustic backscatter the richardson number estimated from observations is larger than 1 4 indicating that the interface is stable however density profiles reveal these preturbulent interfaces to be o 10 cm thick much thinner than can be resolved with shipboard velocity measurements by as

generation and propagation of nonlinear internal waves in massachusetts bay 1 during the summer nonlinear internal waves nliws are commonly observed propagating in massachusetts bay the topography of the area is unique in the sense that the generation area over stellwagen bank is only 25 km away from the shoaling area and thus it represents an excellent natural laboratory to study the life cycle of nliws to assist in the interpretation of the data collected during the 1998 massachusetts bay internal wave experiment mbiwe98 a fully nonlinear and nonhydrostatic model covering the generation shoaling region was developed to investigate the response of the system to the range of background and driving conditions observed simplified models were also used to elucidate the role of nonlinearity and dispersion in shaping the nliw field this paper concentrates on the generation process and the subsequent evolution inthe basin themodel was foundtoreproducewell the range of propagation characteristics observed arrival time propagation speed amplitude and provided a coherent framework to interpret the observations comparison with a fully nonlinear hydrostatic model shows that during the generation and initial evolution of the waves as they move away from stellwagen bank dispersive effects play a negligible role thus the problem can be well understood considering the geometry of the characteristics along which the riemann invariants of the hydrostatic problem propagate dispersion plays a role only during the evolution of the undular bore in the middle of stellwagen basin the consequences for modeling nliws within hydrostatic models are briefly discussed at the end

three dimensional reconstruction of an in situ miocene peat forest from the lower rhine embayment northwestern germany new methods in palaeovegetation analysis palaeovegetation reconstructions particularly of fossil forests are generally restricted to scant information on the taxonomic composition relative abundance of individual taxa or on tree density we have developed new techniques for the analysis of stump horizons that result in a relatively detailed three dimensional reconstruction of ancient forests in addition a rough estimate of their above ground standing biomass can be calculated these techniques are applied to an in situ miocene peat forest preserved in the lower rhine embayment northwestern germany in a study area of 2500 m2 476 stumps were mapped and used in the forest reconstruction additionally pollen samples and leaf remains have been analysed the peat forest consists primarily of conifers in particular taxodiaceae and pinaceae with sciadopitys being the most common genus the only angiosperms in the wood flora were palms but in the pollen flora evidence for the myricaceae mastixiaceae ericaceae and a few other angiosperms is also present the forest was relatively dense with 1904 trees ha and a basal area of 164 m2 mean trunk diameter was 28 cm while mean tree height is calculated to have been 9 9 m height diameter and density distribution are illustrated using contour and three dimensional surface plots estimated above ground biomass is 750 t ha but this value also includes dead or partly dead trees this peat forest does not closely compare with previous reconstructions of miocene peat forests its three dimensional structure and biomass differ from those of modern bald cypress swamps

early pennsylvanian ombrotrophic mire of the prokop coal upper silesian basin what does it say about climate abstract the lower pennsylvanian kinderscoutian prokop coal coal no 40 the erosional remnant of which covers about 5000 km 2 is the thickest seam of the upper silesian basin situated along the czech polish border this basin wide coal is unusual in its thickness and high inertinite and very low ash contents in the czech sector this coal merges with the overlying coal no 39 into a single 9 to 15 m thick seam maceral analyses of an approximately 11 m thick section of these two merged coals show changes in the proportion of vitrinite 24 7 88 0 and inertinite 8 5 56 8 in cycles between 50 and 190 cm thick the increase of inertinite in the lower part of coal cycles coincides with a dulling upward trend which records a drying upward succession due to a slowing of accommodation rate relative to plant biomass productivity this succession is interpreted as a transition from rheotrophic to ombrotrophic conditions the brightening upward succession in the upper part of coal cycles records a wetting upward trend due to water table rise resulting in restoration of rheotrophic conditions that supported humification under the regional ground water table the sudden shift from inertinite rich to vitrinite rich coal at the base of brightening upward successions points to a period of degradation and lowering of the peat dome the coal cycles within the studied seam section probably preserve a succession of spatially overlapping but genetically independent mires bounded by degradation surfaces the alternation between mires with contrasting hydrological regimes is interpreted as a record of base level fluctuations of climatic causation of sub milankovitch periodicities early pennsylvanian climate for various stages of mire development is inferred from analogy with modern tropical mires in se asia

geologically controlled agricultural contamination and water rock interaction in an alluvial aquifer results from a hydrochemical study hydrogeochemistry data collected from three multi level monitoring wells in a sandy alluvial aquifer located in the keum river watershed south korea are used in this study to evaluate groundwater chemistry change in relation to geologic controls of groundwater recharge redox condition water rock interaction and contamination susceptibility a silt layer at a depth of about 10 m is a hydrologic barrier which prohibits the continued downflow of groundwater and divides the groundwater into two distinct masses i e shallow oxic groundwater and deeper sub oxic groundwater with different redox states and ion chemistry compared to sub oxic water oxic water has lower sio2 na k and higher ca no3 and so4 indicating significant contamination from agrochemicals and manures the higher ca and no3 but lower hco3 concentrations in oxic water result from lime dissolution and nitrification in contrast sub oxic water shows increased sio2 and hco3 suggesting the effect of water rock interaction in the aquifer potential sources of cations are na from albite mg from chlorite and illite and k from illite vertical fluctuations of cationic composition in sub oxic water suggest heterogeneity of aquifer mineralogy with depth mineral stability calculations show that the chemistry of oxic water plots in the kaolinite field while that of sub oxic water plots in the ca montmorillonite field and near the kaolinite montmorillonite equilibrium boundary concentrations of dissolved inorganic carbon dic in sub oxic water are much higher than total alkalinity hco3 co3 suggesting that co2 generated by redox reactions such as denitrification iron reduction and sulfate reduction causes increasing dic which also affects the dissolution of silicate minerals in an aquifer free of carbonate minerals

interplay between tectonics and compaction in a rift margin lacustrine delta system miocene of the eger graben czech republic the early miocene bilina palaeodelta consists of fluvio deltaic and lacustrine clastics deposited along the south eastern margin of the extensional most basin part of the eger graben in north bohemia czech republic the bilina succession shows evidence of repeated advances of an axial deltaic system across a thick accumulation of organic material and clay in the hangingwall of an active fault exposures up to ca 4 5 km long in the bilina open cast mine help bridge the gap between seismic scale and typical outcrop scale of observation and thus allow the relationships between small scale and basin scale stratal geometries to be evaluated the bilina palaeodelta deposits include sand dominated fluvial channel fills and heterolithic sheets interpreted as delta plain strata sand dominated mouth bar wedges and heterolithic sheets of prodeltaic deposits passing distally into lacustrine clays the depositional environment is interpreted as a fluvial dominated mixed load lacustrine delta with a high degree of grain size segregation at the feeder channel mouths on the largest temporal and spatial scales variable tectonic subsidence controlled the overall advance and retreat of the delta system the medium term transgressive regressive history was probably driven by episodes of increased subsidence rate however at this temporal scale the architecture of the deltaic sequences deltaic lobes and correlative lacustrine deposits was strongly affected by i compaction of underlying peat and clay which drove lateral offset stacking of medium term sequences and ii growth of a fault propagation fold close to the active bilina fault at the smallest scale the geometries of individual mouth bars and groups of mouth bars short term sequences reflect the interaction among sediment loading compaction and growth faulting that produced high frequency relative lake level fluctuations and created local accommodation at the delta front

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

petrographical and organic geochemical investigation of the oberpfalz brown coal deposit west germany abstract a detailed macro and micropetrographical investigation coupled with gc and gc ms analysis of the alkane fraction of tertiary brown coal samples from the oberpfalz region of bavaria west germany was undertaken distinctive petrographical and organic geochemical facies differences were evident in the coal seams investigated which came from two neighbouring open cast mines the lower seam was of a limnic nature while the upper seam in the neighbouring mine showed the more typical characteristics of terrestrial depositon both seams were generally characterized by high ash contents and extract yields microlayering and framboidal pyrite the predominance of texto ulminite a combined with relatively high resinite contents suggested that gymnosperms were the main peat forming plants additionally the coal extracts were characterized by the presence of the diterpane phyllocladane which made up to 60 of the alkane fraction in some samples bacterial activity in the coal swamp was marked by the presence of hopanes mainly 17a h 21 h homohopane and biodegradation of the n alkanes

vegetation differences and diagenetic changes between two bulgarian lignite deposits insights from coal petrology and biomarker composition abstract during the miocene numerous sedimentary basins formed on the territory of bulgaria as a result of the extensional tectonic settings related to the post orogenic development of the late alpine orogen in this study we review the petrographic composition and biomarker assemblage of two adjacent basins in western bulgaria i e beli breg and staniantsi basins both contain lignite formed during late miocene c 6 ma despite similar tectonic settings and depositional environments the lignite seams possess different petrographic and organic geochemical characteristics reflecting differences in the peat forming palaeo communities and facies variations the peat forming vegetation in beli breg basin was dominated by decay resistant coniferous plants as indicated by abundant fossil wood remains very good tissue preservation and a biomarker assemblage dominated by diterpenoids in contrast staniantsi lignite is poor in fossil wood and contains a significant amount of triterpenoid biomarkers suggesting the predominance of angiosperm plants in the swamp the results of the biomarker analyses are consistent with palaeobotanical and palynological data from the literature the lignite seams in both basins formed under frequently changing eh conditions as indicated by the severe degradation of the non gymnosperm tissues the low gelification index values and the variations in pristane phytane ratio probably as a result of seasonal drying of the swamps and changes of the ground water table hopanoid contents in beli breg lignite are very low and are consistent with the abundance of decay resistant vegetation in contrast bacterial activity was obviously higher in the staniantsi swamp however resulting only in slightly enhanced gelification of plant tissues the geochemical data suggest that the diagenetic changes of the organic matter were mainly governed by thermal degradation rather than bacterial activity