characterization and migration of atmospheric ree in soils and surface waters abstract rainwater and snow collected from three different sites in france vosges mountains french alps and strasbourg show more or less similar shapes of their ree distribution patterns rainwater from strasbourg is the most ree enriched sample whereas precipitations from the two mountainous less polluted catchments are less ree enriched and have concentrations close to seawater they are all strongly lree depleted different water samples from an alpine watershed comprising snow interstitial puddle and streamwater show similar ree distributions with lree enrichment rainwater normalized but mree and hree depletion in this environment where water transfer from the soil to the river is very quick due to the low thickness of the soils it appears that ree in streamwater mainly originate from atmospheric inputs different is the behaviour of the ree in the spring and streamwaters from the vosges mountains these waters of long residence time in the deep soil horizons react with soil and bedrock ree carrying minerals and show especially significant negative eu anomalies compared to atmospheric inputs their sr and nd isotopic data suggest that most of the sr and nd originate from apatite leaching or dissolution soil solutions and soil leachates from the upper soil horizons due to alteration processes strongly depleted in ree carrying minerals have ree distribution patterns close to those of lichens and throughfall throughfall is slightly more enriched especially in light ree than filtered rainwater probably due to leaching of atmospheric particles deposited on the foliage and also to leaf excretion data suggest that sr and nd isotopes of the soil solutions in the upper soil horizons originate from two different sources 1 an atmospheric source with fertilizer dust and seawater components and 2 a source mainly determined by mineral dissolution in the soil these two different sources are also recognizable in the sr and nd isotopic composition of the tree s throughfall solution the atmospheric contributions of sr and nd to throughfall and soil solution are of 20 to 70 and 20 respectively in springwater however the atmospheric sr and ree contribution is not detectable

238u234u230th disequilibrium in hydrogenous oceanic femn crusts palaeoceanographic record or diagenetic alteration abstract a detailed tims study of 234uexc 238u 230th 232th and th u ratios have been performed on the outermost margin of ten hydrogenous fe mn crusts from the equatorial pacific ocean and west central indian ocean th u concentration ratios generally decrease from the crust s surface down to 0 5 1 mm depth and growth rates estimated by uranium and thorium isotope ratios are significantly different in fe mn crusts from the peru basin and the west central indian ocean fe mn crusts from the same geographical area define a single trend in plots of ln 234uexc 238u vs ln 230th 232th and th u ratios vs age of the analysed fractions results suggest that l hydrogenous fe mn crusts remain closed systems after formation and consequently 2 the discrepancy observed between the 230th and 234u chronometers in fe mn crusts and the variations of the th u ratios through the margin of femn crusts are not due to redistribution of uranium and thorium isotopes after oxyhydroxide precipitation but rather to temporal variations of both th u and initial thorium activity ratios recorded by the fe mn layers implications of these observations for determination of fe mn crust growth rates are discussed variations of both th u and initial th activity ratios in fe mn crusts might be related to changes in particle input to seawater and or changes in ocean circulation during the last 150 ka

controls on transport and fractionation of the rare earth elements in stream water of a mixed basaltic granitic catchment basin massif central france abstract we present rare earth element ree patterns of small streams from a catchment basin in the massif central france in order to characterize the individual fractionation stages for the dissolved ree from the source to the catchment outlet the upper part of the catchment is located on a basalt plateau followed downstream by deep and narrow valleys within granitic and orthogneissic bedrock basalt normalized 0 45 m filtered stream water has ree patterns slightly depleted in the light ree la sm lree on the basalt plateau close to the source followed by a continuous amplification of this lree depletion downstream at the same time also a negative ce anomaly develops in the adsorbed fraction of 0 45 m particles which has been isolated by leaching with 1 m hcl strontium and neodymium isotope ratios of stream water demonstrate that the dissolved ree are essentially of basaltic origin even in the lower granitic and gneissic part of the catchment mixing with gneiss or granite derived ree thus cannot explain the observed evolution of the ree patterns our data suggest that the ree of the 0 45 m particles in contrast to earlier studies we found no link between ree behavior and organic colloids or organic complexes this scenario is confirmed by a detailed analysis of the ree patterns at 3 stream confluences the results show that the ree do not behave conservatively during mixing at stream confluences but that the lree and ce are preferentially removed similarly to what has been observed at catchment scale our study thus underlines the importance of fe colloids for the transport and fractionation of the ree in stream water

response of late carboniferous and early permian plant communities to climate change abstract late carboniferous and early permian strata record the transition from a cold interval in earth history characterized by the repeated periods of glaciation and deglaciation of the south

the geology and palynology of lower and middle pennsylvanian strata in the western kentucky coal field abstract the western kentucky coal field is the southern tip of the eastern interior or illinois basin pennsylvanian rocks in this area which include conglomerate sandstone siltstone shale limestone and coal were deposited primarily in coastal deltaic settings at a time when western kentucky was located close to the equator this paper discusses temporal changes in regional sedimentation patterns and coal forming floras of lower and middle pennsylvanian strata in the western kentucky coal field lower pennsylvanian strata of the caseyville formation are characterized by paleovalley filling sedimentation patterns and extabasinal quartz pebbles caseyville formation coals are characteristically thin and discontinuous and were strongly influenced by subsidence within underlying paleovalleys and the dissected lower pennsylvanian paleotopography caseyville coals are commonly dominated by lycospora but can also have variable palynofloras which probably reflects variable edaphic conditions and edge effects within small patchy paleomires tradewater formation strata show increased marine influences and tidal estuarine sedimentation especially in the middle and upper parts coal beds in the lower part of the tradewater typically are thin and discontinuous although some economically important beds are present coals become thicker more abundant and more laterally persistent towards the top of the formation palynologically lower and middle tradewater formation coals are dominated by lycospora but begin to show increased amounts of tree fern spores middle and upper tradewater coals are thicker and more continuous and contain high percentages of tree fern spores in addition cordaite pollen is locally abundant in this interval carbondale and shelburn desmoinesian strata are much more laterally continuous and occur within classic cyclothems that can be traced across the coal field cyclothems have long been interpreted as being eustatically driven and glacio eustacy controlled not only sedimentation but also the formation of desmoinesian paleomires palynologically carbondale and shelburn coals are either dominated by lycospora or have heterogeneous palynofloras palynologic and coal quality data suggest that hydrologic base level may have been the primary control on desmoinesian paleomires rather than paleoclimate as the coals display rheotrophic rather than ombrotrophic characteristics

vegetational history of the springfield coal middle pennsylvanian of illinois and distribution patterns of a tree fern miospore thymospora pseudothiessenii based on miospore profiles abstract the vegetational history of the springfield no 5 coal member in the southwestern and southeasternmost portion of the illinois basin is reconstructed from palynological profiles of the coal seam in most parts of the swamp dominance was shared by arborescent lycopods that produced lycospora granulata and two tree ferns that produced thymospora pseudothiessenii and laevigatosporites globosus the profiles suggest that populations of the thymospora producing tree fern occupied sites for long periods in the southwestern portion of the basin vegetation changes can be correlated to the splitting of a coal in the proximity to a paleochannel a greater understanding of the ecological requirements of some of the spore taxa of the springfield coal is seen by the patterns of the same taxa in surrounding spoon and carbondale coals some taxa appear to be more generalists and other more specialists that are more restricted to a certain type of coal

modelling weathering processes at the catchment scale the witch numerical model a numerical model of chemical weathering in soil horizons and underlying bedrock witch has been coupled to a numerical model of water and carbon cycles in forest ecosystems aspects to simulate the concentration of major species within the soil horizons and the stream of the strengbach granitic watershed located in the vosges mountains france for the first time simulations of solute concentrations in soil layers and in the catchment river have been performed on a seasonal basis the model is able to reproduce the concentrations of most major species within the soil horizons as well as catching the first order seasonal fluctuations of aqueous calcium magnesium and silica concentrations however the witch model underestimates concentrations of mg2 and silica at the spring of the catchment stream and significantly underestimates ca2 concentration the deficit in calculated calcium can be compensated for by dissolution of trace apatite disseminated in the bedrock however the resulting increased ca2 release yields important smectite precipitation in the deepest model layer in contact with the bedrock and subsequent removal of large amount of silica and magnesium from solution in contrast the model accurately accounts for the concentrations of major species ca mg and silica measured in the catchment stream when precipitation of clay minerals is not allowed the model underestimation of mg2 and h4sio4 concentrations when precipitation of well crystallized smectites is allowed strongly suggests that precipitation of well crystallized clay minerals is overestimated and that more soluble poorly crystallized and amorphous materials may be forming in agreement with observations on other watersheds draining granitic rocks this study indicates that highly soluble trace calcic phases control the aqueous calcium budget in the strengbach watershed

using short lived nuclides of the u and th series to probe the kinetics of colloid migration in forested soils abstract the recent chemical dynamics of a podzolic forest soil section from the strengbach watershed france was investigated using u and th series nuclides analyses of 238 u 230 th 226 ra 232 th 228 ra and 228 th activities in the soil particles the seepage waters and the mature leaves of the beech trees growing on this soil were performed by tims or gamma spectrometry the simultaneous analysis of the different soil sl compartments allows to demonstrate that a preferential th leaching over ra must be assumed to explain the 226 ra 230 th 228 ra 232 th and 228 th 228 ra disequilibria recorded in the soil particles the overall ra and th transfer schemes are entirely consistent with the prevailing acido complexolysis weathering mechanism in podzols using a continuous open system leaching model the 226 ra 230 th and 228 ra 232 th disequilibria measured in the different soil layers enable dating of the contemporary processes occurring in this soil in this way we have determined that a preferential th leaching from the shallow ah horizon due to a strong complexation with organic colloids began fairly recently 18 years ago at most the continual increase in ph recorded in precipitations over the last 20 years is assumed to be the cause of this enhanced organic complexation a lower soil horizon 50 60 cm is also affected by preferential th leaching though lasting over several centuries at least with a much smaller leaching rate the migration of th isotopes through this soil section might hence be used as a tracer for the organic colloids migration and the induced radioactive disequilibria demonstrate to be useful for assessing the colloidal migration kinetics in a forested soil ra and th isotopic ratios also appear to be valuable tracers of some mineral water plant interactions occurring in soil the 228 ra 226 ra ratio enables discrimination of the ra flux originating from leaf degradation from that originating from mineral weathering in shallow 10 cm seepage soil waters it appears that at least in some cases the ra isotopic ratio measured in forest soil seepage waters may not be representative of the ra isotopic ratio released from mineral weathering indicating that the different origins of the dissolved 226 ra and 228 ra must be taken into account

geochemical petrographic and palynologic characteristics of two late middle pennsylvanian asturian coal to shale sequences in the eastern interior basin usa abstract two coal to shale sequences of late middle pennsylvanian asturian age from the southern portion of the eastern interior illinois basin usa were examined geochemically petrographically and palynologically the springfield coal was found to be moderately low in ash yield and high in total sulfur content petrographically the coal is high in vitrinite content and low in liptinite and inertinite palynologically the bed is co dominated by spores of arborescent lycopod and tree fern affinities the examination of closely spaced bench samples revealed vertical species variation within both of these plant groups lycospora micropapillata l orbicula both of which were produced by paralycopodites are most abundant in basal coal benches whereas lycospora granulata produced by lepidophloios is the dominant arborescent lycopod spore throughout the rest of the bed thymospora pseudothiessenii is the dominant tree fern spore throughout most of the coal with laevigatosporites globosus becoming dominant in the top most coal benches the herrin coal bed is also moderately low in ash yield and high in total sulfur content unlike the springfield coal it contains two distinct inorganic partings that have regional extent the herrin coal also has several coal benches with increased ash and sulfur that were not present in the springfield coal bed petrographically it is dominated by vitrinite with the partings and high ash coal benches containing more inertinite and liptinite palynologically the herrin coal is dominated by arborescent lycopod spores with subdominant tree fern spores as with the springfield coal lycospora micropapillata l orbicula are the dominant arborescent lycopod spores at the base of the coal with lycospora granulata dominating the rest of the bed granasporites medius which was produced by diaphorodendron and synchysidendron occurs more frequently in the herrin coal bed and are most abundant in and in proximity to the two inorganic partings tree fern spores are less abundant in the herrin coal and do not display any discernable vertical species variation collectively both the springfield and herrin coal beds are interpreted to have formed in extensive planar topogenous mires consistently saturated peat conditions throughout the development of both paleomires are indicated by the high vitrinite contents and prevalence of arborescent lycopods the deposition of widespread inorganic partings in the herrin coal represents significant events in peat accumulation with high ash coal benches representing smaller more local events both of the coals are overlain by black very organic rich avg toc 20 marine shales the turner mine shale which directly overlies the springfield coal has layers at the coal shale contact with fairly abundant vitrinite primarily in the form of vitrodetrinite near the base of the shale but the majority of the shale is dominated by the liptinite macerals bituminite lamalginite and amorphinite micrinite is a major organic component of the shale the anna shale which directly overlies the herrin coal is similar in overall maceral composition but contains less vitrinite and more solid bitumen and micrinite trace element ratios ni co v cr v v ni indicative of paleoredox conditions indicate that both shales were deposited under mainly dysoxic to suboxic anoxic conditions the shales are interpreted to represent a progressively rising water table caused by an increase in eustatic sea levels vitrinite reflectance values in the shales are lower than corresponding values measured from the coal indicating some degree of vitrinite suppression occurring in the turner mine and anna shales

234u 238u activity ratios in freshwaters as tracers of hydrological processes the strengbach watershed vosges france abstract 234u 238u and 87sr 86sr isotopic ratios as well as major and trace u ba sr rb element concentrations were analyzed in dissolved loads of the strengbach stream vosges france in order to constrain the sources of u isotopes 234u 238u to river waters the variations of the 234u 238u activity ratios along the stream indicate a clear dependence between the 234u 238u activity ratios of the surface waters and the different types of rocks forming the watershed with near equilibrium values for the waters draining granites and high 234u 238u disequilibria 1 4 for those flowing over carbonates the high 234u 238u disequilibria are related to a supply of 234u enriched groundwaters located within the carbonate rocks the 234u 238u activity ratios of the waters at the outlet of the catchment collecting the sources of the stream on the granitic lithology decrease from 1 02 to 0 96 when the discharge of the stream increases such a tendency requires mixing between a water body enriched in 234u which weathered the granitic bed rock at secular equilibrium and a water with a 234u 238u activity ratio below unity representing a mobilization of u from material that has already been weathered comparison of the geochemical characteristics of waters collected during the year and those collected during a flood event reveals the involvement of two different weathered end members depending on the hydrological conditions during the year the dissolved u transported by the river originates from bed rock and deep horizons of the weathering profile whereas a significant part of u during the flood event is supplied by superficial horizons of soils probably complexed by organic colloids these results outline the potential of 234u 238u activity ratios to investigate hydrological processes and emphasize that their use as tracers of rock weathering should be made cautiously

the calcium riverine and hydrothermal isotopic fluxes and the oceanic calcium mass balance calcium isotope ratios relative to seawater were studied in natural waters in order to constrain the ca isotopic flux to the oceans and to discuss the oceanic ca budget this study includes the analysis of 1 ca isotopes in continental waters at the regional scale of the upper rhine valley and 2 the determination of the 44ca values of some major rivers and hydrothermal vents the data indicate that the global 44ca variability of the studied waters with a maximal range of 1 is limited and must be linked to mass fractionation processes at the scale of a small watershed aubure vosges france the 44ca river flux changes due to the variation of the proportion of waters resulting from chemical alteration of rocks and biologically fractionated soil solutions ca isotopes could therefore be an important tool to quantify the impact of the plants and the biosphere on the river water chemistry at the regional scale of the rhine valley as well as at the global scale of world rivers the 44ca variability of river samples ranges from 0 5 to 1 without any relationship with the lithology of the watershed or the climate similarly the 44ca value of hydrothermal vents is also uniform and close to the mean value of river waters consequently the 44ca flux to the ocean should remain rather constant through time with a mean of 1 1 0 2 this value confirms that the ca budget of the present day seawater is in steady state this was not necessarily the case in the past non steady state periods should have been due to intensity variations of incoming and outcoming ca fluxes rather than to the variations in their isotopic signatures

boron isotopes in different grain size fractions exploring past and present water rock interactions from two soil profiles strengbach vosges mountains abstract in the present study we test the ability of b isotopes to trace past and present weathering reactions in the case of two forest soils formed by a polyphasic sequence involving early hydrothermal alteration of the bedrock and pedogenesis we provide b chemical and isotopic compositions in two 2 m soil profiles sampled in the strengbach watershed vosges france the two soils belong to different soil series an ochreous podzol haplorthod and a brown acidic soil dystrochrept developed on the same granitic bedrock but differently affected by hydrothermal alteration separated granulometric fractions and bulk soil samples have been analyzed coarse particles are mostly composed of primary minerals and show a clear anti correlation between 11 b and mg al reflecting various grades of the early hydrothermal alteration the finest particles clay size fractions deviate from this hydrothermal trend and are diagnostic of pedogenic processes occurring after b exchange with the surrounding 11 b rich soil solution examination of the b distribution in different particle size fractions also indicates that b is transferred from the coarse sand fraction in deeper soil layers to the clay fraction in the upper layers the intermediate size fractions are found to play only a secondary role in the soil forming reactions the two soils show distinct b isotope profiles which are consistent with the different pedogenic processes that govern their formation in the podzolic soil 11 b can be explained by a simple model in which pedogenesis occurs by continuous dissolution of primary minerals and precipitation of secondary ones in the brown acid soil a more complex model that includes the precipitation of clay minerals in the deep horizon and their gradual dissolution in the upper soil layers accounts for the observed results additionally residual hydrothermal illites are more resistant to weathering and are found in the clay fraction where they were directly inherited from the dislocation of coarser grains in which they were encapsulated on a broader scale the large b isotopic fractionation during water rock interactions greatly facilitates the quantification of matter exchange between soil solutions and solids and the determination of global weathering rates the data from the present study demonstrate that the determination of b isotopes in different particle size fractions can reveal the relative importance of source and process effects during weathering

u th ra fractionation during weathering and river transport the potential of radioactive disequilibria as tracers and chronometers of weathering processes has been recognised since the 1960 s e g rosholt et al 1966 hansen and stout 1968 this interest results from the dual property of the nuclides of the u and th radioactive series 1 to be fractionated during water rock interactions and 2 to have radioactive periods of the same order of magnitude as the time constants of many weathering processes and chemical transfers to ground and river waters therefore the study of radioactive disequilibria in surface environments should help to bring information about the nature the intensity but also the time scale of the water rock interactions produced during weathering and related chemical transfers these different properties have justified many of the studies on u th series in weathering profiles and river waters rosholt 1982 scott 1982 and osmond and ivanovich 1992 gave a synthesis of the studies of u series in weathering and surface hydrology up to the 1980 s and the 1990 s respectively here we present the main directions taken in these domains over the last decade they were partly stimulated by the analytical developments made in the measurement of the medium half life nuclides of 238u series i e 234u 230th 226ra in the mid 1980 s namely the use of thermal ionisation mass spectrometry tims e g chen et al 1986 edwards et al 1987 cohen et al 1991 chabaux 1993 chabaux et al 1994 and more recently the use of mc icp ms turner et al 2001 robinson et al 2002 for u and th isotope analysis details of these developments are given in this volume goldstein and stirling 2003 compared to the radioactive counting methods previously used the new techniques permit 1 a reduction by one order of magnitude or more of the size of the sample required for

geochemical and isotopic sr u monitoring of soil solutions from the strengbach catchment vosges mountains france evidence for recent weathering evolution abstract this study presents the results of a geochemical and isotope u and sr study of soil solutions from two experimental sites in the strengbach catchment one under spruce trees and the other under beech trees the soil solution data combined with the data from soil and vegetation samples indicate that the dissolved u filtered to 0 45 m in the soil solutions is primarily of lithogenic origin implying that the colloidal u is secondarily associated with organic matter or organo metallic complexes present in the soil solutions the uranium activity ratios and sr isotope ratios of soil solutions are used to decipher the nature of the minerals that control the lithogenic contribution to the soil solutions a comparison of soil solution data collected over the period 2004 2006 with those collected over the period 1993 2010 indicates a decrease in the ca and k exported by the soil solutions between 1998 and 2004 at the spruce site and a significantly smaller decrease at the beech site in addition the sr isotope ratios of the soil solutions vary significantly between these two periods at the spruce site but not or much less at the beech site such observations suggest that the forest ecosystem at the spruce site is in a transient state associated with recent changes in weathering reactions the data also suggest that the comparison of u and sr isotopes in soil solutions and plant samples could be a relevant method for determining whether a forest ecosystem is in a steady or transient state

238u234u230th chronometry of femn crusts growth processes and recovery of thorium isotopic ratios of seawater abstract comparison of 234 u excess 238 u and 230 th 232 th activity ratios in oceanic fe mn deposits provides a method for assessing the closed system behaviour of 238u 234u 230th as well as variations in the initial uranium and thorium isotopic ratios of the precipitated metal oxides this approach is illustrated using a fe mn crust from lotab seamount marshall islands west equatorial pacific here we report uranium and thorium isotopic compositions in five subsamples from the surface of one large 5 cm diameter botryoid of this crust and from two depth profiles of the outermost rim of the same botryoid the decrease of 234 u excess 238 u and 230 th 232 th activity ratio with depth in the two profiles gives mean growth rates for the last 238u 212th 150 ka of 7 8 2 mm ma and 6 6 1 mm ma respectively all data points surface and core samples but one define a linear correlation in the ln 230 th 232 th ln 234 u excess 238 u diagram this correlation indicates that for all points the u th system remained closed after the fe mn layer precipitated and that the different samples possessed the same initial uranium and thorium isotope ratios furthermore these results show that the preserved surface of this fe mn crust may not be the present day growth surface and that the thorium and uranium isotopic ratios of seawater in west equatorial pacific have not changed during the past 150 ka the initial thorium activity ratio is estimated from the correlation obtained between ln 230 th 232 th ln 234 u excess 238 u

dunkard group coal beds palynology coal petrography and geochemistry abstract coal beds that occur in the dunkard group are typically thin avg 0 3 m and are high in ash yield avg 27 8 and total sulfur content avg 5 1 petrographically dunkard coals are high in vitrinite avg 83 1 mmf with correspondingly low to moderate amounts of liptinite avg 2 1 mmf and inertinite avg 13 8 mmf palynologically dunkard coal beds are all dominated by tree fern spore taxa avg 96 3 especially punctatisporites minutus avg 82 8 calamite spores are the second most abundant plant group avg 2 4 with others lycopods small ferns cordaites and other gymnosperms having very minor representation overall the coal palynofloras are strongly dominated by lowland plants ferns and calamites with only rare occurrences of bisaccate striate conifer pollen coal beds of the underlying monongahela group pittsburgh redstone sewickley and waynesburg are thicker avg 1 6 m and are lower in ash avg 13 4 and sulfur avg 3 3 than their dunkard counterparts petrographically monongahela group coals are very similar to dunkard group coals when compared on a mineral matter free basis coal beds that occur in both groups are strongly dominated by vitrinite macerals monongahela group coals are also palynologically very similar to dunkard group coals with tree fern spore taxa dominating a coal bed of early permian age from west central texas is also similar petrographically and palynologically to dunkard and monongahela coals being vitrinite and tree fern spore dominant the almost complete lack of coniferous pollen in dunkard coals led earlier workers to conclude that the dunkard was entirely late pennsylvanian and not permian in age however it is now known that late pennsylvania lowland floras persisted into the dunkard especially during wet intervals as earlier interpretations were based primarily on spore and pollen floras from coal beds the lack of conifer pollen in dunkard coals is probably the result of a sampling bias because of this ecological bias coal palynology is a poor proxy for age dating dunkard group coals collectively dunkard swamps were all planar and topogenous their formation being controlled by topography and moisture availability a progressive decrease in wet intervals both in terms of frequency and duration during the dunkard was the major control on peat accumulation and preservation collectively moisture limitation appears to be the principle factor that controlled the formation of dunkard group coals

palynology petrography and geochemistry of the sewickley coal bed monongahela group late pennsylvanian northern appalachian basin usa abstract forty two bench samples of the sewickley coal bed were collected from seven localities in the northern appalachian basin and analyzed palynologically petrographically and geochemically the sewickley coal bed occurs in the middle of the pittsburgh formation monongahela group and is of late pennsylvanian age palynologically it is dominated by spores of tree ferns tree fern spore taxa in the sewickley include punctatisporites minutus punctatosporites minutus laevigatosporites minimus spinosporites exiguus apiculatasporites saetiger and thymospora spp in fact punctatisporites minutus was so abundant that it had to be removed from the standard counts and recorded separately average 73 2 even when punctatisporites minutus is removed from the counts tree fern spores still dominate a majority of the assemblages averaging 64 4 among the tree fern spores identified in the sewickley coal thymospora exhibits temporal and spatial abundance variation thymospora usually increases in abundance from the base to the top of the bed thymospora is also more abundant in columns that are thick 100 cm and low in ash yield calamospora spp laevigatosporites minor and l vulgaris are the next most abundant plant group represented in the sewickley coal averaging 20 contributions from all other plant groups are minor in comparison petrographically the sewickley coal contains high percentages of vitrinite average 82 3 mineral matter free mmf with structured forms being more common than unstructured forms in contrast liptinite and inertinite macerals both occur in low percentages average 7 7 and 10 0 respectively geochemically the sewickley coal has a moderate ash yield average 12 4 and high total sulfur content average 3 4 four localities contained a high ash or carbonaceous shale bench these benches which may be coeval are strongly dominated by tree fern spores unlike the lower ash benches they contain low percentages of vitrinite which mainly occurs as unstructured vitrinite and higher liptinite and inertinite contents the accumulated data suggest that the sewickley paleomire was probably a rheotrophic planar mire that had a consistent water cover this is supported by the high vitrinite contents moderate ash yields and high total sulfur contents the high ash and carbonaceous shale benches probably represent either periods of dryness and substrate exposure or flooding of the mire surface the duration of which is unknown

persistence of late carboniferous tropical vegetation during glacially driven climatic and sea level fluctuations abstract the late carboniferous glaciation reached its peak during the latter part of the westphalian late desmoinesian in the tropical illinois basin this was the time of deposition of the carbondale and lower modesto formations characterized by the cyclic repetition of major coal deposits black shales limestones gray shales and sandstones these lithological changes evidence repeated major fluctuations in climate and sealevel fossil floras from the tropical ever wet to seasonally wet terrestrial lithofacies coals and shales above coals remain compositionally similar throughout the 1 1 5 m y time interval floras from coals known from coal balls and palynology characteristically were composed of three major plant communities the wettest sites were dominated by monocarpic lycopsids intermediate sites were dominated by polycarpic lycopsids and areas subject to fires and intermittent flooding were dominated by medullosans and the small lycopsid paralycopodites clastic substrate environments were dominated by ferns and pteridosperms and conform to a single biozone indicating their compositional unity and distinctness from earlier and later assemblages the composition of lowland floras is poorly known from times between the deposition of coals and associated terrestrial rocks intervals during which most of the lowlands were flooded and marine rocks were being deposited consequently the temporally intermittent recurrence of lowland floras despite repeated widespread environmental disruption may be explained either by vegetational persistence and migration of floras or repeated disruption and reassembly several lines of evidence suggest persistence as a likely explanation

u isotope ratios as tracers of groundwater inputs into surface waters example of the upper rhine hydrosystem major elements trace elements and sr and u isotopes were analyzed in the dissolved load of water samples collected in the main reservoirs of the rhine graben i e the rhine river its main tributaries and the shallow and deep ground waters in several different aquifers our results confirm that the variations of major elements trace elements especially sr and rb and sr isotope ratios of the water samples are mainly correlated to the lithological variations of the watershed the atmospheric inputs can be considered as a minor cause for the chemical variability of the surface waters in the rhine hydrosystem except for a few chemical elements in the mountain streams human activity in particular the pollution by the exploitation of the alsace potash mines mainly affects the na and cl concentrations of the rhine and the south alluvial groundwaters but remains negligible for the other water samples the specific study of the lauter stream located in the lower triassic sandstones buntsandstein sequences demonstrates the importance of groundwater influences onto the chemical composition of river waters up to 50 of the total dissolved load tds of this stream is supplied by deep waters this contribution significantly modifies the chemical composition of the stream especially the 238u 234u radioactive disequilibrium which in turn can be used as a specific tracer of deep water inputs into surface waters and could be useful to distinguish in the dissolved load of rivers surface weathering fluxes from deeper ones

rare earth elements and sr and nd isotopic compositions of dissolved and suspended loads from small river systems in the vosges mountains france the river rhine and groundwater abstract the aim of this study is to characterize the evolution of the rare earth elements ree in non mature streams from small catchment areas in the vosges mountains downstream to more mature plain rivers including the river rhine the dissolved load ree distribution patterns of the low ph vosges streams are very different from those of high ph plain rivers indicating that different physico chemical parameters control ree transport in these different water systems the plain rivers and groundwater show similar ree distribution patterns with a strong negative ce anomaly and heavy rare earth element hree enrichment in addition the river rhine has a positive gd anomaly which is of anthropogenic origin similar to the world s major rivers the light rare earth element lree enrichment in the plain rivers is mainly ph controlled their sm nd and 143 nd 144 nd isotope ratios are close to average continental crust values this is not the case for the less evolved non mature and low ph vosges streams their high sm nd and 143 nd 144 nd ratios but low 87 sr 86 sr ratios suggest that chemical alteration of accessory middle rare earth element mree enriched minerals such as apatites from rocks in the catchment area control the ree abundances of these waters a comparison of the dissolved load ree distribution patterns with those of the principal lithologies in the corresponding drainage basins illustrates that especially the eu anomalies of the vosges streamlets are strongly lithology dependent leaching experiments indicate that the suspended load is isotopically very inhomogeneous the ree distribution patterns of the suspended load leachates have no similarities with those of the corresponding dissolved load indicating that the leachable reservoir not only contains adsorbed ree but also ree from leachable mineral phases their 143 nd 144 nd sm nd and 87 sr 86 sr ratios support this suggestion being always higher and lower respectively than those of their corresponding dissolved loads they rather point to the presence of relic primary apatite in the leachable portion of the suspended load the flat paas normalized ree distribution patterns the high 87 sr 86 sr and low 143 nd 144 nd isotopic ratios of the corresponding residues suggest secondary silicate phases such as clay minerals in the residual phase of the suspended load leachates and corresponding residual phases define alignments in the sm nd isochron diagram whose slopes define ages ranging between 200 and 390 ma indicating that the mineral phases in the suspended load retain some memory of their primary precursor minerals in the hercynian granitic source rocks

ree fractionation during granite weathering and removal by waters and suspended loads sr and nd isotopic evidence very few studies deal with ree rare earth element mobility within the system soil soil solution streamwater in this article we try to characterize the fractionation and the migration of the ree in a granite derived soil system located in a small catchment of the vosges mountains icp ms and tims measurements were performed on both solid samples fresh granite soil and suspended load of the stream and waters soil solutions springwater and streamwater to determine their respective ree concentrations and sr and nd isotopic compositions the paas normalized ree pattern of the bedrock is characterized by a strong depletion in hree heavy ree and a negative eu anomaly 0 46 similarly the granite normalized ree distribution patterns of the soil samples show hree depletions that become more important with decreasing depth the correlative behavior between p2o5 th and ree with depth indicates that besides apatite other phosphate minerals such as monazite are the most important phases controlling the th and ree budget in the soil profile on the other hand at greater depth zircon seems to be another important mineral phase controlling especially the hree enrichment as shown by the positive relationship between zr content and the yb ho ratio different grain size fractions show similar ree distribution patterns and are only weakly fractionated compared with bulk soil sample however the finest fraction 0 20 m is more enriched in sr and ree suggesting a stronger concentration of ree carrying minerals in this fraction the suspended and dissolved load of the stream show as a whole an enrichment in hree if compared with the granite or with the different soil samples however compared with the uppermost soil samples the suspended load is significantly more enriched in hree its ree distribution pattern is more similar to that of the finest fraction of the deeper soil sample and to the fresh granite thus most probably the ree of the suspended load originated from a source with ree characteristics found in the deep soil horizons this source might have been situated in the uppermost soil profile which is actually ree depleted the weathering process can be compared with a leaching experiment where the waters correspond to the leachate and the soil to the residual phase of the granite the sr isotope data indicate that the suspended load originates from the finest soil fraction the sr and nd isotopic data of the suspended load suggest that it contains up to 3 sr and nd from apatite and up to 97 from feldspar most of the sr and nd in the waters originate from apatite leaching or dissolution

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

lithium isotope systematics in a forested granitic catchment strengbach vosges mountains france abstract over the last decade it has become apparent that li isotopes may be a good proxy to trace silicate weathering however the exact mechanisms which drive the behaviour of li isotopes in surface environments are not totally understood and there is a need to better calibrate and characterize this proxy in this study we analysed the li concentrations and isotopic compositions in the various surface reservoirs soils rocks waters and plants of a small forested granitic catchment located in the vosges mountains strengbach catchment france ohge http ohge u strasbg fr li fluxes were calculated in both soil profiles and at the basin scale and it was found that even in this forested basin atmospheric inputs and litter fall represented a minor flux compared to input derived from the weathering of rocks and soil minerals which together represent a minimum of 70 of dissolved li li isotope ratios in soil pore waters show large depth dependent variations average dissolved 7 li decreases from 1 1 to 14 4 between 0 and 30 cm but is 30 7 at 60 cm this range of li isotopic compositions is very large and it encompasses almost the entire range of terrestrial li isotope compositions that have been previously reported we interpret these variations to result from both the dissolution and precipitation of secondary phases large isotopic variations were also measured in the springs and stream waters with 7 li varying from 5 3 to 19 6 7 li increases from the top to the bottom of the basin and also covaries with discharge at the outlet these variations are interpreted to reflect isotopic fractionations occurring during secondary phase precipitation along the water pathway through the rocks we suggest that the dissolved 7 li increases with increasing residence time of waters through the rocks and so with increasing time of interaction between waters and solids a dissolution precipitation model was used to fit the dissolved li isotopic compositions it was found that the isotopic compositions of springs and stream waters are explicable by an isotopic fractionation of 5 to 14 best fit 10 8 in agreement with li incorporation into clay in soil solutions it was found that isotopic fractionation during secondary precipitation is larger at least 23 suggesting a major role for different secondary phases such as iron oxides that maybe incorporate li with a higher isotope fractionation

the effects of exposure and climate on the weathering of late pleistocene and holocene alpine soils abstract the main aim of this study was to examine the influence of exposure and consequently climate on the chemical weathering of soils which had developed after the ice retreat of the last glaciation in northern italy this was done by comparing soils developing at north and south facing sites on siliceous parent material there is very little data available on weathering rates and organic matter om as a function of climate and exposure in such environments weathering rates elemental leaching over the whole lifetime of the soils are higher on north facing sites total organic c and n contents organic matter stocks and organic matter fractions were analysed to decipher the causes of this difference in weathering behaviour for the organic matter fractions we compared the easily oxidisable and stable resistant to h 2 o 2 treatment organic matter fractions water soluble phenolic materials and alkaline extractable fractions of the various sites the abundance of soil organic carbon soc tends to have a non linear climate dependency the highest amounts of soc were measured near the timberline in addition compared to south facing sites soils on north facing slopes have a higher organic matter content and a significantly lower degree of humification undecomposed or weakly degraded organic matter accumulated on north facing sites due to less favourable thermal conditions and a higher acidity with northern exposure fulvic acids were more easily transported within the soil profile than humic acids and predominately gave rise to the migration eluviation of fe and al compounds due to their cooh and oh functional groups furthermore water soluble phenolic materials which are more abundant on north facing sites have accelerated the leaching of al accumulation of weakly degraded om and the subsequently higher production of organic ligands have enhanced the eluviation of fe and al patterns of weathering processes in alpine environments are strongly linked to biological and micro climatic factors which give rise to distinct differences between north and south facing sites

erosion and weathering fluxes in granitic basins the example of the strengbach catchment vosges massif eastern france abstract this work reports on regular observations of the suspended sediment and bedload flux at the outlet of the granitic strengbach catchment 0 8 km over the period 2004 2010 along with the analysis of the dissolved load the data set allows a first determination of the physical erosion flux 3 3 t km 2 yr 1 exported out of the strengbach watershed and how it compares to the chemical weathering flux of basic cations the data indicate that the erosion rate carried by the bedload 1 7 t km 2 yr 1 can reach one third of the total erosion rate 5 t km 2 yr 1 in the strengbach watershed the accuracy of these rates is estimated to be 20 the study also indicates that the estimated values for the net annual weathering flux calculated for the watershed can differ by a factor of two or more depending on the corrections applied and the assumptions retained for the watershed s functioning from an uncorrected weathering flux of basic cations of 4 76 t km 2 yr 1 to an atmosphere corrected weathering flux of 2 t km 2 yr 1 for the period 2004 2010 the weathering budgets determined for the strengbach catchment fit the general trend defined between the weathering rate and runoff for other granitic watersheds this suggests that the anthropogenic impact due to acid perturbation or forest management has a relatively weak influence on the weathering intensity within the watershed the relationship between weathering and erosion rates determined for the strengbach catchment does not significantly differ from those established for other previously studied granitoid catchments

coal facies studies in the eastern united states coals in the eastern united states east of the mississippi river have been the subject of a number of coal facies studies going back to the 19th century such studies would not necessarily fall within a strict modern classification of coal facies studies but if a study encompassed some aspects of paleobotany palynology petrology geochemistry or sedimentology we assumed that some data and interpretations may be of use in evaluations of the facies references are presented as a guide for further research with annotation in the tables

geochemical tracing and hydrogeochemical modelling of water rock interactions during salinization of alluvial groundwater upper rhine valley france in the southern upper rhine valley groundwater has undergone intensive saline pollution caused by the infiltration of mining brines a consequence of potash extraction carried out during the 20th century major and trace elements along with sr and u isotopic ratios show that groundwater geochemical characteristics along the saline plumes cannot reflect conservative mixing between saline waters resulting from the dissolution of waste heaps and one or more unpolluted end members the results imply the occurrence of interactions between host rocks and polluted waters and they suggest that cationic exchange mechanisms are the primary controlling process a coupled hydrogeochemical model has been developed with the numerical code kirmat which demonstrates that cationic exchange between alkalis from polluted waters and alkaline earth elements from montmorillonite present in the host rock of the aquifer is the primary process controlling the geochemical evolution of the groundwater the model requires only a small amount of montmorillonite between 0 75 and 2 25 which is in agreement with the observed mineralogical composition of the aquifer the model also proves that a small contribution of calcite precipitation dissolution takes places whereas other secondary mineral precipitation or host rock mineral dissolution do not play a significant role in the geochemical signature of the studied groundwater samples application of the model demonstrates that it is necessary to consider the pollution history to explain the important cl na and ca concentration modifications in groundwater samples taken over 2 km downstream of waste heaps additionally the model shows that the rapidity of the cationic exchange reactions insures a reversibility of the cation fixation on clays in the aquifer

vegetational zonation in a swamp forest middle pennsylvanian illinois basin u s a indicates niche differentiation in a wetland plant community abstract a rich fossil flora occurs in the roof shale of the middle pennsylvanian moscovian age springfield coal flanking the galatia channel a river deposit approximately 1 km in width and 150 km long partially contemporaneous with the springfield peat swamp siltstone and sandstone 30 m thick were deposited in the channel during the final estuarine phase the river formed under seasonal subhumid climate during early deglaciation as marine waters retreated from the land surface it existed continuously through glacial maximum under increasingly humid climate as a low sediment or black water river with peat along its flanks during early deglaciation under subhumid climate and sea level rise the river became a sediment laden estuary drowning the peat swamp and burying vegetation in place under extensive mudflats this buried flora was studied in three underground mines in southern illinois permitting vegetation to be characterized spatially three transects comprising 100 sites a total linear distance of 12 km reveal distinct zonation perpendicular to the channel margin an innermost belt 0 5 to 2 5 km wide consists almost exclusively of the pteridosperm neuropteris flexuosa north of a river bend three belts succeed the n flexuosa zone mixed pteridosperms and marattialean tree ferns mixed arborescent lycopsids and marattialians lycopsids with rare marattialians south and inside the same bend n flexuosa is succeeded by mixed lycopsids particularly sigillaria and marattialean ferns within the transects marattialian ferns have wider distribution than other groups suggesting broader environmental tolerances neuropteris flexuosa channel margin mono dominance may reflect high sedimentation rates elevated nutrient conditions or floating seed dispersal lycopsid dominance in interior areas conforms with tolerance of deep standing water the spatial scale examined affects our perception of community assembly overall distinct vegetational zonation suggests niche assembly however within vegetational bands there is considerable small scale spatial variation suggesting stochastic properties

u series disequilibria in suspended river sediments and implication for sediment transfer time in alluvial plains the case of the himalayan rivers 238u 234u 230th radioactive disequilibria were analyzed in suspended sediments collected at different depths from the ganges river and one of its main tributaries the narayani gandak river results associated with bedload sediment data suggest that uranium series u series disequilibria in river sediments of the ganges basin vary with grain size and sampling location the range of observed u series disequilibria is explained by a mixing model between a coarse grained sediment end member represented by bedload and bank sediments and a fine grained end member that both originate from himalaya but undergo different transfer histories within the plain the coarse grained sediment end member transits slowly i e several 100 s ky in the plain whereas the fine grained sediment end member is transferred much faster 20 25 ky as indicated by the absence of significant variations in th isotope composition of the fine grained sediment end members these results show that u series isotopes can be used to quantify the various transfer times of river sediments of different sizes and infer that there can be an order of magnitude of difference or more between the transfer time of suspended and bedload sediments this underlines that a good knowledge of the proportion of suspended vs bedload sediments transported in the river is required to accurately assess how fast erosion products are transferred in a catchment and how fast a catchment is likely to respond to external forcing factors

stratigraphic and interregional changes in pennsylvanian coal swamp vegetation environmental inferences abstract quantitative analysis of pennsylvanian coal swamp vegetation provides a means of inferring organization and structure of communities distribution of these communities further provides inferences about environmental factors including paleoclimate our observations are based on in situ structurally preserved peat deposits in coal ball concretions from 32 coal seams in the eastern one half of the united states and from several seams in western europe and on spore assemblages from more than 150 seams there were three times of particularly significant and nearly synchronous vegetational changes in the midcontinent and appalachian coal regions during the pennsylvanian period each was different in kind and magnitude the first marked changes occurred during the early part of the middle pennsylvanian with the fluctuating decline in the high level of lycopod dominance the abundance of cordaites increased there was a rise in the occurrences of the lycopod herbs to form intercalated marshlands and an overall increase in floral diversity changes ensuing from this time also include shifts in dominant species of lycopod trees and a sustained rise in abundance and diversity of tree fern spores the next significant time of change was during the middle part of the middle pennsylvanian representing both a culmination of earlier trends and expansions of cordaites in the midcontinent where there was a maximum change in species without net loss of diversity tree ferns and medullosan pteridosperms attained subdominant levels of abundance and diverse lycopod species dominated except in the atokan desmoinesian transition of the midcontinent the third and sharpest break occurred near the middle late pennsylvanian boundary when extinctionsof the dominant coal swamp lycopods allowed development of tree fern dominance the late pennsylvanian coal swamps apparently were colonized or recolonized mainly by species from outside coal swamps rather than by the survivor populations of the middle pennsylvanian swamps paralleling the changes in floras through the pennsylvanian are changes in preservational aspects of the peat these include a decline in shoot root ratios from approximately 1 to

influence of eolian deposition and rainfall amounts on the u isotopic composition of soil water and soil minerals 230th u dating of secondary deposits such as speleothems and pedogenic carbonate and opal provides information about the original 234u 238u composition of the waters the minerals precipitated from as a result these types of deposits often display temporal variations in initial 234u 238u that could reflect environmental variability past variations in soil water 234u 238u may reflect changes in the flux of water through the soil weathering rates or dust inputs in order to evaluate these potential influences we analyzed modern soil water chemistry and u isotopic compositions of fluids and solids from three soil sequences in nevada modern soil pore waters from diamond valley newark valley and fish lake valley nevada show significant 234u 238u differences between sites as a result of differing soil parent material newark valley pore waters are more heavily influenced by carbonate weathering and display much more enriched 234u 238u values than diamond and fish lake valley pore waters which are dominated by silicate weathering newark valley and diamond valley although located very near to each other have significantly different pore water 234u 238u values suggesting that deposition of distantly sourced dust does not exert a dominant influence on pore water 234u 238u at these sites pore water 234u 238u values also vary systematically along a rainfall gradient at fish lake valley where sites with lower rainfall display higher soil water 234u 238u values the results of this modern soil water chemistry study were used to parameterize two models that investigate the relative influence of dust content recoil and weathering on pore water 234u 238u in the upper layer of the soil and at depth under changing infiltration rates these models suggest that while the composition of soluble dust entering a soil profile is an important consideration the pore water 234u 238u at depth and thus the initial 234u 238u of minerals that precipitate from pore waters should be highly sensitive to changes in the infiltration flux through the soils as infiltration flux is closely tied to rainfall the initial 234u 238u of soil minerals at these sites should provide information about past rainfall variability

chemical mobilizations in laterites evidence from trace elements and 238u 234u 230th disequilibria geochemical and mineralogical investigations including measurements of major and trace elements sr isotope ratios and 238u 234u 230th activity ratios were made on an old african laterite to reconstruct its formation steps and assess recent chemical mobilization the present data support a scenario of discontinuous formation for the laterite with different bedrock weathering conditions during the formation of each unit rather than a scenario of continuous formation absolute accumulation of fe u and lanthanides in the uppermost ferruginous unit suggests an autochthonous origin of this iron cap by leaching of an older overlying profile present chemical distributions of lanthanides as well as of rb k ba and sr within the profile cannot be linked to the mineralogical distribution of both relictual primary and authigenic secondary phases complementary lanthanide patterns indicate that these elements were primarily accumulated in the uppermost ferruginous unit before further remobilization and accumulation in the underlying horizons these redistribution processes may be related to the chemical instability of the ferruginous cap the 238u 234u 230th disequilibria indicate that recent u mobilization occurs in the whole profile and that as for lanthanides there is a vertical redistribution of u from the uppermost ferruginous unit to the underlying horizons moreover these data show that both u losses and gains exist at each level of the profile a simple modeling of this double u mobilization process is proposed to interpret the 238u 234u 230th data differences in the mobilization and fractionation intensities of the u input and removal processes can account for the two evolution trends which distinguish the ferruginous unit from the underlying ones furthermore on the basis of this modeling the profile appears to be in a transient state because of recent changes in the u mobilization conditions which could correspond to major pleistocene climatic variations

place vs time and vegetational persistence a comparison of four tropical mires from the illinois basin during the height of the pennsylvanian ice age abstract coal balls were collected from four coal beds in the southeastern part of the illinois basin collections were made from the springfield herrin and baker coals in western kentucky and from the danville coal in southwestern indiana these four coal beds are among the principal mineable coals of the illinois basin and belong to the carbondale and shelburn formations of late middle pennsylvanian age vegetational composition was analyzed quantitatively coal ball samples from the springfield herrin and baker are dominated by the lycopsid tree lepidophloios with lesser numbers of psaronius tree ferns medullosan pteridosperms and the lycopsid trees synchysidendron and diaphorodendron this vegetation is similar to that found in the springfield and herrin coals elsewhere in the illinois basin as reported in previous studies the danville coal sample which is considerably smaller than the others is dominated by psaronius with the lycopsids sigillaria and synchysidendron as subdominants coal balls from the springfield coal were collected in zones directly from the coal bed and their zone by zone composition indicates three to four distinct plant assemblages the other coals were analyzed as whole seam random samples averaging the landscape composition of the parent mire environments this analysis indicates that these coals separated from each other by marine and terrestrial clastic deposits have essentially the same floristic composition and thus appear to represent a common species pool that persisted throughout the late middle pennsylvanian despite changes in baselevel and climate attendant the glacial interglacial cyclicity of the pennsylvanian ice age patterns of species abundance and diversity are much the same for the springfield herrin and baker although each coal both in the local area sampled and regionally has its own paleobotanical peculiarities despite minor differences these coals indicate a high degree of recurrence of assemblage and landscape organization the danville departs dramatically from the dominance diversity composition of the older coals presaging patterns of tree fern and sigillaria dominance of late pennsylvanian coals of the eastern united states but nonetheless built on a species pool shared with the older coals

the source of calcium in wet atmospheric deposits ca sr isotope evidence tracing the origin of calcium in wet atmospheric deposits is important for environmental studies since it is a dominant acid neutralising cation and an essential nutrient here we present the first calcium isotope ratio measurements for rain and snow samples from northeastern and southern locations france switzerland luxembourg california and japan suggest a carbonate origin only at a local scale in a forested watershed vosges mountains france the ca isotopic compositions of rainwater indicate that the rainwater becomes admixed with throughfall solution which is a mixing product of ca from dissolved atmospheric dust particles and leave excretions if this proves to be widely true the contribution of ca from the canopy could be very important for the neutralisation of acid rain and of the corresponding soil system in forested watersheds in such cases ca and sr cycles are decoupled in the lower atmosphere in contrast to sr isotopes ca isotopes can be applied to tracing processes occurring in the biosphere

from biological to lithological control of the b geochemical cycle in a forest watershed strengbach vosges abstract there is a fast growing interest in understanding the coupling between mineralogical and biological processes responsible for the migration of elements through continental ecosystems this issue has fundamental impacts at the soil plant scale because it can explain the tight links between soil and plant development and at the watershed scale because it gives a direct access to the water quality in the present study we performed an extended investigation of the bio geochemical cycle of boron which is an element known to be suitable for investigating water rock interactions and vegetation cycling new b data are provided along the hydro bio geochemical continuum in a forest ecosystem strengbach basin vosges france from rainwaters down to the outlet of the basin including systematic analyses of throughfalls soil solutions springs and brooks scattered in the watershed at the watershed scale we evidence a relationship between the b isotopic composition of river waters and the weathering regime outlining a predominant control of the parent rock mineralogy on the b geochemical behavior at the soil plant scale it appears that the b geochemical cycle is controlled by the vegetation cycling which is characterized by an uncommon easy to distinguish b isotopic composition 11b ranging from about 30 to 45 each year the amount of b being involved in the vegetation cycle is about four times greater than that of b being exported out of the watershed at 10 cm depth in soil where the plant roots are expected to be the most active we observe a marked seasonal oscillation of the b isotopic values which is interpreted as resulting from the vegetation activity a mass balance calculation based on the assumption that that 10b is preferentially accumulated in the biomass tends to indicate that the soil plant system does not behave at steady state with respect to b because of the very distinct b isotopic signature of vegetation and minerals in soil box modeling allows to quantify the part of the b fluxes involved in the vegetation cycling and the mineral reactions respectively this calculation reveals a clear correlation between the amount of b derived from soil weathering and the amount of b absorbed by plant roots this result clearly supports the idea that a coupling exists between mineral weathering and plant activity for the study of which b isotopes appear particularly suitable

a new sedimentary benchmark for the deccan traps volcanism 1 the origin of the cretaceous paleogene boundary kpb mass extinction is still the center of acrimonious debates by opposing partisans of the bolide impact theory to those who favored a terrestrial origin linked to the deccan traps volcanism here we apply an original and high resolution environmental magnetic study of the reference bidart section france our results show that the kpb is identified by an abrupt positive shift of the magnetic susceptibility ms also observed by others at the kpb elsewhere in addition an anomalous interval of very low ms carried by an unknown cl bearing iron oxide similar to specular hematite is depicted just below the kpb grain size and morphology of the cl iron oxide are typically in the range of hematitic dust currently transported by winds from sahara to europe this discovery is confirmed in the referenced gubbio section italy suggesting a global scale phenomenon as a conjecture we suggest an origin by heterogeneous reaction between hcl rich volcanic gas and liquid solid aerosols within buoyant atmospheric plumes formed above the newly emitted deccan flood basalts based on this hypothesis our discovery provides a new benchmark for the deccan volcanism and witnesses the nature and importance of the related atmospheric change

baseline determination of the atmospheric pb sr and nd isotopic compositions in the rhine valley vosges mountains france and the central swiss alps abstract the pb sr and nd isotopic compositions of biomonitors lichen moss bark and soil litter from different regions in the rhine valley as well as of

isotopic tracing of the dissolved u fluxes of himalayan rivers implications for present and past u budgets of the ganges brahmaputra system u activity ratios have been measured in the dissolved loads of selected rivers from the himalayan range in central nepal and from the bangladesh as well as in some rain waters a few european and asian rivers have also been analyzed for their u activity ratios the data confirm the negligible effect of rainwater on the budget of dissolved u in river waters the results also indicate that rivers on each himalayan structural unit have homogeneous and specific u isotope compositions i 234u 238u activity ratios slightly lower than unity in the dissolved load of the streams draining the tethyan sedimentary series tss ii values slightly higher than unity for waters from the high himalaya crystalline hhc and the lesser himalaya lh iii systematically higher 234u 238u activity ratios for waters from the siwaliks thus u activity ratios in association with sr isotopic ratios can be used to trace the sources of dissolved fluxes carried by these rivers coupling of u with sr isotope data shows 1 that the u carried by the dissolved load of the himalayan rivers mainly originates from u rich lithologies of the tss in the northern formations of the tibetan plateau and 2 that the elemental u and sr fluxes carried by the himalayan rivers at the outflow of the highlands are fairly homogeneous at the scale of the himalayan chain rivers flowing on the indian plain define a different trend from that of the himalayan rivers in the u sr isotopic diagram indicating the contribution of a specific floodplain component to the u and sr budgets of the ganges and the brahmaputra the influence of this component remains limited to 10 to 15 percent for the u flux but can contribute 35 to 55 of the sr flux the variations of the sr and u fluxes of the ganges brahmaputra river system in response to climatic variations have been estimated by assuming a temporary cut off of the chemical fluxes from high altitude terrains during glacial episodes this scenario would significantly decrease the dissolved u flux of the ganges brahmaputra river system and increase its u activity ratio such a climatic dependence of the himalayan u flux could induce a periodic variation of the mean u activity ratio of the world rivers on glacial interglacial timescales

the impact of vegetation on ree fractionation in stream waters of a small forested catchment the strengbach case previous studies on waters of a streamlet in the vosges mountains eastern france have shown that strontium and rare earth elements ree mainly originate from preferential dissolution of apatite during weathering however stream water ree patterns normalized to apatite are still depleted in the light ree lree la sm pointing to the presence of an additional lree depleting process vegetation samples are strongly enriched in lree compared to stream water and their sr and nd isotopic compositions are comparable with those of apatite and stream water thus the preferential lree uptake by vegetation might lead to an additional lree depletion of surface runoff in the forested catchment mass balance calculations indicate that the yearly lree uptake by vegetation is comparable with the lree export by the streamlet and therefore might be an important factor controlling lree depletion in river water this is underlined by the observation that rivers from arctic and boreal regions with sparse vegetation appear to be less depleted in lree than rivers from tropical environments or boreal environments with a dense vegetation cover

paleoecology of the springfield coal member desmoinesian illinois basin near the leslie cemetery paleochannel southwestern indiana abstract the springfield coal member carbondale group petersburg formation of indiana is split locally in warrick and gibson counties indiana by clastic rocks of the folsomville member carbondale group petersburg formation that represent the leslie cemetery paleochannel part of a large interconnected paleochannel system in the springfield coal bed this study incorporated analysis of miospore and megaspore assemblages coal petrography plant compression fossils and conodonts from the coal and clastic split to document changes in the swamp and its vegetation in response to the activity of the leslie cemetery paleochannel palynological and petrographic data indicate that environmental conditions and vegetation in the lower bench of coal near the leslie cemetery paleochannel were similar to those found in profiles through the coal bed at sites near the larger more extensive galatia paleochannel miospore floras of the high vitrinite lower bench of coal were dominated by tree fern miospores with those of lycopsids ranking second in abundance megaspore assemblages were dominated by lycopsid megaspores near the contacy between the lower bench of coal and clastic split medullosan prepollen increases in abundance and fusain bands are more common which may indicate the occurrence of fire either within or outside the swamp vegetation in the folsomville member and upper bench of coal differ markedly from that of the lower bench of coal plant megafossils from the folsomville member indicate dominance by pteridosperms and or lycopsids and folsomville member miospore assemblages are dominated by lycopsid miospores most typically found in mudstones including lycospora torquifer and higher than normal abundances of granasporites medius in the transition from clastic rocks of the folsomville member to the upper bench of coal miospores of ecotonal lycopsids paralycopodites reach their peak abundance pteridosperms dominate megafossil assemblages and inertinite levels are relatively high at higher levels of the upper bench of coal vitrinite levels are higher and miospore assemblages are dominated by lycopsid miospores typical of coal swamps lycospora granulata l pusilla the presence of conodonts in coalballs in the upper bench of coal and spirorbid worms in the split indicate that the paleoswamp may have received some marine or brackish water influence higher than normal salinity levels may explain the vegetational changes observed in the upper bench of coal near the leslie cemetery paleochannel

the isotopic fingerprint of fe cycling in an equatorial soil plant water system the nsimi watershed south cameroon abstract following an initial study of a tropical lateritic hillside system showing little iron isotope fractionation despite a strong accumulation within the soil profile the present work investigates iron isotope signatures within the organic matter rich swamp system that represents 20 of the studied watershed surface from nsimi south cameroon this study considers the soil plant water continuum in order to better understand the fe elemental and isotopic transfer out of the ecosystem within the swamp system the iron isotope compositions of gleysol samples 57 fe irmm 14 0 6 are significantly heavier than both the continental crust baseline and the reference lateritic soils from the hillslope 57 fe irmm 14 0 1 this enrichment towards heavy isotopes is attributed to a preferential removal of light iron isotopes during soil forming processes pedogenic transformations i e gleyzation organic complexation of metal and leaching are responsible for the reductimorphic features observed in ferralitic horizons i e incomplete degradation of organic matter in surface and soil whitening favored by good draining conditions the organic carbon rich waters of the swamp system are prone to redox processes and strong metal chelation the dissolved iron i e fraction 57 fe signatures with a downstream enrichment in heavy isotopes from 0 511 0 266 to 1 076 0 240 the binding of iron fe iii with organic matter can explain the observed enrichment in heavy isotopes in the dissolved fraction on the contrary plant leaves are significantly enriched in light fe 57 fe of 0 665 0 035 and 1 119 0 080 relative to i the litter compartment 0 166 0 078 to 0 262 0 013 for 57 fe and ii the most superficial soils iron isotopic compositions in plants and litter vary as a function of both plant species and season hence the differences in fe isotopic compositions between the various studied compartments suggest that fe isotopes can be used i to study elemental transfers during soil pedogenesis in tropical environment and ii to better appraise and constrain iron biogeochemical cycle between surface horizon of soils surface waters and the vegetation

impact of atmospheric deposition biogeochemical cycling and water mineral interaction on ree fractionation in acidic surface soils and soil water the strengbach case leaf litter contains not only important quantities of elements derived from decomposition of organic matter but also atmospheric compounds this is illustrated by sr and nd isotope data from soils of the strengbach catchment which show that soil litter contains more than 50 of atmospheric sr and nd downward migrating soil water becomes strongly acidic during flow through litter and humus layers ph 3 8 4 at 5 10 cm depth causing not only intense mobilization of elements in the underlying acid brown and podzolic soils at depths between 10 and 50 cm but also the downward transfer of some litter derived compounds the sr and nd isotope data allow to quantify that soil water from 10 to 70 cm depth contains 45 to 65 of litter derived nd and sr sequential leaching experiments have been performed on soil samples in order to recover adsorbed trace elements or those fixed in acid soluble mineral phases such as fe mn oxyhydroxides and phosphate minerals the isotope data of these leachates of the uppermost soil horizons point similarly to the presence of important quantities of litter derived sr and nd in the uppermost 30 cm of the soils with the exception of the litter layer the soil profiles are substantially depleted in ca and p down to 50 cm depth which can be related to low apatite and plagioclase contents these minerals have probably been preferentially weathered and ca and p have been removed by percolating soil water and plant uptake leaching of primary granite derived apatite controls rare earth element ree fractionation only below 50 cm depth rhabdophane ree po4 has been observed as secondary replacement mineral of apatite this replacement is reflected by ca p ratios that are low at the surface and which increase regularly with depth implying that some of the apatite derived p has been integrated into newly formed rhabdophane and some of the p and ca have been exported either by soil solutions or plant uptake during downward transport litter derived elements are adsorbed on soil particles and or coprecipitate with authigenic minerals such as fe mn oxyhydroxide or rhabdophane alternatively litter derived elements may remain in solution or like ca be absorbed by vegetation the soil solutions from the uppermost 30 cm of the soil profiles and the corresponding soil leachates show very similar ree distribution patterns and are compared to the waters of the strengbach stream which drains the forested catchment strongly enriched in light rare earth elements lree however soil solutions from 60 to 70 cm depth are compared to litter strongly lree depleted and show stream water like ree distribution patterns it is suggested that this evolution of the ree in the soil solutions is due to the following processes taking place above 50 cm depth 1 precipitation of lree rich phosphate minerals like rhabdophane 2 diminution of the formation of organic dissolved or colloidal phases in association with fe mn and al oxyhydroxides and 3 preferential lree uptake by vegetation below 50 cm the ree distribution patterns are further modified by dissolution precipitation reactions and adsorption the combination of all these fractionation processes finally leads to the ree patterns of the strengbach stream at the catchment outlet

the impact of water rock interaction and vegetation on calcium isotope fractionation in soil and stream waters of a small forested catchment the strengbach case this study aims to constrain the factors controlling the calcium isotopic compositions in surface waters especially the respective role of vegetation and water rock interactions on ca isotope fractionation in a continental forested ecosystem the approach is to follow changes in space and time of the isotopic composition and concentration of ca along its pathway through the hydro geochemical reservoirs from atmospheric deposits to the outlet of the watershed via throughfalls percolating soil solutions and springs the study is focused on the strengbach catchment a small forested watershed located in the northeast of france in the vosges mountains the 44 40ca values of springs brooks and stream waters from the catchment are comparable to those of continental rivers and fluctuate between 0 17 and 0 87 soil solutions however are significantly depleted in lighter isotopes 44 40ca 1 00 1 47 whereas vegetation is strongly enriched 44 40ca 0 48 to 0 19 these results highlight that vegetation is a major factor controlling the calcium isotopic composition of soil solutions with depletion in light calcium in the soil solutions from deeper parts of the soil compartments due to preferential 40ca uptake by the plants rootsystem however mass balance calculations require the contribution of an additional ca flux into the soil solutions most probably associated with water rock interactions the stream waters are marked by a seasonal variation of their 44 40ca with low 44 40ca in winter and high 44 40ca in spring summer and autumn for some springs nourishing the streamlet a decrease of the 44 40ca value is observed when the discharge of the spring increases with in addition a clear covariation between the 44 40ca and corresponding h4sio4 concentrations high 44 40ca values and low h4sio4 concentrations at high discharge low 44 40ca values and high h4sio4 concentrations at low discharge these data imply that during dry periods and low water flow rate the source waters carry a ca isotopic signature from alteration of soil minerals whereas during wet periods and high flow rates admixture of significant quantities of 40ca depleted waters vegetation induced signal from uppermost soil horizons controls the isotopic composition of the source waters this study clearly emphasizes the potential of ca isotopes as tracers of biogeochemical processes at the water rock vegetation interface in a small forested catchment