funmig integrated project results and conclusions from a safety case perspective abstract the scope of the funmig integrated project ip was to improve the knowledge base on biogeochemical processes in the geosphere which are relevant for the safety of radioactive waste repositories an important part of this project involved the interaction between data producers research and data users radioactive waste management organisations in europe the aim thereof was to foster the benefits of the research work for performance assessment pa and in a broader sense for the safety case of radioactive waste repositories for this purpose a specifically adapted procedure was elaborated thus relevant features events and processes feps for the three host rock types clay crystalline and salt were taken from internationally accepted catalogues and mapped onto each of the 108 research tasks conducted during the funmig project by a standardised procedure the main outcome thereof was a host rock specific tool task evaluation table in which the relevance and benefits of the research results were evaluated both from the pa and research perspective virtually all generated data within funmig are related to the safety relevant fep groups transport mechanisms and retardation generally speaking much of the work within funmig helped to support and to increase confidence in the simplified pa transport and retardation models used for calculating radionuclide rn transport through the host rock some of the studies on retardation processes e g coupled sorption redox processes at the mineral water interface yielded valuable data for all three rock types dealt within the ip however most of the studies provided improved insight regarding host rock specific features and processes the majority of this work being dedicated to clay rich and crystalline host rocks for both of these host rock types funmig has significantly contributed to improving understanding on a conceptual level both by providing new experimental data at different spatial scales and by developing improved modelling approaches the disposal concept in salt host rocks differs from those in other host rock types in that the host rock is at least in part regarded as near field from which under normal scenarios no release of radionuclides is possible corresponding investigations in funmig concerned therefore not salt host rocks but an example of an overburden under the premise of radionuclide escape from the salt barrier selected highlights with regard to funmig s achievements include for argillaceous host rocks the systematic effort of investigating and comparing diffusion and sorption processes at different scales in different clay rocks using a variety of methods has substantially increased the knowledge basis for future safety cases for crystalline host rocks valuable data on the generation transport and filtration of clay colloids from the near field and their impact on rn transport under realistic conditions have been obtained the results from studies on organic colloids and on biofilms including their interaction with radionuclides have been shown to be of interest for future safety cases of salt host rocks among the main research issues from a pa perspective that need to be addressed in the future the following are noted i the question of irreversibility of rn sorption to colloids in fractures of crystalline rocks ii a comprehensive model for cation and anion diffusion in clays for different scales and iii the applicability of mechanistic retardation models for strongly sorbing radionuclides in intact clay and crystalline host rocks an important lesson learnt from the interaction between research and pa is that it would be desirable to apply a similar evaluation procedure for proposed research tasks before the start of the research work in this regard the procedures developed within funmig are a useful tool for planning future integrated projects

origin of the groundwater salinity and geochemical processes in detrital and carbonate aquifers case of chougafiya basin central tunisia summary comprehensive investigations of groundwaters were performed in the detrital and carbonate aquifers of the chougafiya basin central tunisia in the present review hydrochemistry and isotopic tools were combined to get an insight into the processes controlling mineralization recharge conditions flow pattern of groundwater and c chemistry in the investigated hydrological system analysis of the dissolved constituents revealed that several processes controlled the observed chemical composition i the dissolution of evaporitic minerals ii cation exchange reactions iii sulfate reduction under anaerobic conditions iv incongruent dissolution of carbonate minerals calcite dolomite coupled with gypsum dissolution and calcite precipitation and v silicates weathering data inferred from 18o and deuterium isotopes in groundwater samples indicated recharge with modern rainfall water characterized by lower 18o and 2h values is interpreted as recharged by non evaporated rainfall originating from mediterranean and atlantic air masses however water with relatively enriched 18o and 2h contents is thought to reflect the occurrence of an evaporation process related to the long term practice of flood irrigation the radiogenic 3h isotope data provided insight into the presence of two recharge periods in the investigated groundwaters waters with 3h contents of 1 tu clearly suggested the occurrence of a contemporaneous recharge probably during the last two decades carbon isotopes provided some insights into the timescales of groundwater flow but mainly revealed that main sources of c are active in the system these are likely dissolved biogenic co2 carbonate dissolution and incongruent reaction of the carbonate matrix mean residence times were determined after correction of the initial activities for dead c from the rock matrix and suggest ages ranging from the present day to the holocene in both upper cretaceous and mio pliocene groundwaters

lower crustal granulite xenoliths from the pannonian basin hungary part 1 mineral chemistry thermobarometry and petrology lower crustal granulite xenoliths have been found in pliocene basaltic tuffs at two newly discovered localities in the western pannonian basin most of them are mafic meta igneous rocks among which garnet rich lithologies are common in general clinopyroxene garnet and plagioclase with minor ilmenite and scapolite dominate their mineralogy several are amphibole bearing which is interpreted as evidence for a recent metasomatic event in the lower crust beneath the pannonian basin meta sedimentary granulite xenoliths have also been identified in the region for the first time their mineralogy is characterised by the absence of clinopyroxene combined with a high proportion of al rich phases especially plagioclase and garnet together with subordinate spinel sphene rutile orthopyroxene and quartz one sample contains biotite and several contain graphite thermobarometric results indicate temperatures and pressures of 800 950 c and 8 15 kbar for all xenolith types considerably higher than for most granulite xenoliths from other regions of phanerozoic europe given that the pannonian basin is currently underlain by thin crust 25 30 km thick the pressure estimates indicate that the crust must have been considerably thicker 40 50 km prior to the tertiary collapse in the region the higher pressures recorded for the meta igneous xenoliths thus suggest that they formed at or before a time when the crust was thicker i e pre tertiary a composite meta igneous meta sedimentary xenolith provides direct evidence for interaction between sediments or metasediments and the magmas that gave rise to the meta igneous granulites indicating that the metasediments are at least as old as the meta igneous granulites the protoliths of the meta igneous xenoliths had primitive mafic to slightly evolved tholeiitic liquid compositions they are dominated by lree depleted compositions that resemble those of mid ocean ridge basalts such compositions are rare in lower crustal xenolith suites they are also very low in large ion lithophile elements such as k and rb but relatively enriched in ba and pb a few slightly lree enriched meta igneous xenoliths are also k and rb depleted in contrast the meta sedimentary granulites are strongly lree enriched but have very variable lile contents one possible explanation for the unusual compositions is a process of subduction accretion of oceanic crust beneath the continental crust rather than basaltic underplating

late pleistocene precipitation δ18o interpolated across the global landmass global water cycles ecosystem assemblages and weathering rates were impacted by the 4 c of global warming that took place over the course of the last glacial termination fossil groundwaters can be useful indicators of late pleistocene precipitation isotope compositions which in turn can help to test hypotheses about the drivers and impacts of glacial interglacial climate changes here a global catalog of 126 fossil groundwater records is used to interpolate late pleistocene precipitation 18o across the global landmass the interpolated data show that extratropical late pleistocene terrestrial precipitation was near uniformly depleted in 18o relative to the late holocene by contrast tropical 18o responses to deglacial warming diverged late pleistocene 18o was higher than modern across india and south china but lower than modern throughout much of northern and southern africa groundwaters that recharged beneath large northern hemisphere ice sheets have different holocene pleistocene 18o relationships than paleowaters that recharged subaerially potentially aiding reconstructions of englacial transport in paleo ice sheets global terrestrial late pleistocene precipitation 18o maps may help to determine 3 d groundwater age distributions constrain pleistocene mammal movements and better understand glacial climate dynamics

carbon isotopes to constrain the origin and circulation pattern of groundwater in the north western part of the bohemian cretaceous basin czech republic abstract the bohemian cretaceous basin represents a complex hydrogeological system composed of several aquifers with very favourable hydrogeological properties these aquifers have been exploited for many years the sustainability of such resources might be guaranteed by well organised water management which requires a detailed knowledge about the functioning of the hydrogeological system although many efforts have previously been made to evaluate groundwater residence time the many intricate geochemical processes complicate groundwater dating the current study clarifies the functioning of this complex hydrogeological basin using hydrogeochemical and isotopic investigations chemical data and a combination of 13 c and 14 c isotopes within the cenomanian and the turonian layers indicate groundwater interactions with deep seated co 2 rock matrix surface waters and fossil organic matter very depleted 13 c values average 13 c 13 4 suggest interactions with fossil organic matter whereas enriched values account for the interaction with deep co 2 gas ascending from the upper mantle via the numerous faults and fractures and also to a lesser extent from calcite dissolution geochemical processes that take place in the system cause a clear depletion in 14 c that greatly complicates groundwater residence time evaluation different dilution correction models have been applied considering the different c origins the stable isotope content mainly 18 o values indicates both the contribution of modern precipitation and the partial infiltration of palaeowaters during colder climatic conditions from the end of the pleistocene the apparent 14 c groundwater ages range from modern to 11 1 ka bp which suggests some post glacial infiltration from melting ice sheets finally all the acquired information was used to propose a conceptual model of c origin within the basin

observations simulations and analysis of nonstationary trapped lee waves abstract although considerable understanding of mountain waves has been gained with the aid of the steady state assumption it is clear that mountain waves evolve over time group velocity arguments indicate that this evolution can occur in less than 1 h this study uses observations of trapped lee waves to measure the rate at which their horizontal wavelengths change including a detailed analysis of two events in which such changes are clearly documented in one case doppler lidar observations show a steady increase in horizontal wavelength of 6 h 1 over 4 h and clearly illustrates the relationship between the wave clouds and wave motions in a second case visible satellite imagery reveals an increase in wavelength of 14 h 1 which is related to temporal changes in vertical air motions measured by wind profilers within the wave field hourly vertical profiles of wind and virtual temperature measured by radio acoustic sounding systems rass and wind profilers reveal important changes in the wave env

analysis and simulations of a troposphere stratosphere gravity wave model i abstract an analytical model is presented that accommodates nonhydrostatic shearing stratified flow over an obstacle and that can be modified to include a superposed stratosphere with constant wind and higher stability a simulation code is used in parallel with the analytic calculations to demonstrate a methodology for determining the wavelength and magnitude of gravity wave energy reflected and that transmitted by the tropopause

real system analyses natural analogues this paper gives an overview of the behaviour of u in two natural systems the forsmark site a granitic system in sweden and the ruprechtov site a tertiary sedimentary system in the czech republic which have been investigated in the frame of the funmig project it is not a full review paper on u geochemistry it shows how different approaches and methods have been used to derive information on u solubility and speciation on characteristics of key processes as well as on timescales of these processes and accordingly information on the long term stability of u phases in the natural systems the results are set in a wider context by relation to selected results from other sites

anomalous arsenic concentrations in the ďurkov carbonate geothermal structure eastern slovakia concentrations of as in carbonate reservoirs in slovakia are relatively low with an average value of 0 72 mg l in typical waters of ca mg hco3 type in factor analysis arsenic is in factor 1 with na and cl separated from carbonate aquifer species ca and mg in factor 2 a principal exception is the urkov site in eastern slovakia where as concentration reaches 36 7 mg l median 30 mg l in geothermal waters of the na cl type the 2h and 18o isotopes indicate a primary meteoric origin of the water low 2h and 14c reflect infiltration of surface water during a warmer climatic period in the early holocene meanwhile positive 18o shift about 5 suggests enhanced water rock interactions the conceptual model of as rich water formation includes the following steps a infiltration of meteoric waters and dissolution of evaporates especially halite in the overlying neogene formation b reaction of the highly mineralized water with hg as sb type of mineralization related to the neogene volcanism and c accumulation of as rich geothermal water in triassic carbonates with an additional input of co2 geochemical modeling of the reaction between water and arsenopyrite reproduced measured as concentrations for a typical range of reservoir temperatures analogous to similar geothermal sites around the world concentrations of arsenic in carbonate reservoirs in slovakia are low except for cases where as is enriched by previous water rock interaction related to neogene volcanic activity outside the carbonate reservoirs which then serve exclusively for a secondary accumulation of as rich waters

carbon chemistry and groundwater dynamics at natural analogue site ruprechtov czech republic insights from environmental isotopes abstract hydrological geochemical and environmental isotope data from groundwater wells at ruprechtov natural analogue site were evaluated to characterize the flow pattern and c chemistry in the system the results show that water flow in the tertiary sediments is restricted to 1 2 m thick zones in the so called clay lignite horizon with two different infiltration areas in the outcropping granites in the western and south western part of the investigated area generally the flow system is separated from the underlying granite by a kaolin layer up to several tens of metres thick differences in stable isotope signatures in the northern part of the site indicate very local connections of both flow systems via fault zones the observed increase of 13c values and decrease of 14c activities in dissolved inorganic c during evolution of the groundwater from the infiltration area to the clay lignite horizon was modelled using simple open and closed system models as well as an inverse geochemical model netpath which included changes in other geochemical parameters the results from both types of models provided some insights into timescales of groundwater flow but mainly revealed that additional sources of c are active in the system these are very likely biodegradation of dissolved and sedimentary organic c doc and soc as well as the influx of endogenous co2 the occurrence of microbial degradation of soc in the clay lignite layers is indicated by the increase of biogenic dic doc and phosphate concentrations the impact of microbial so4 reduction on this process is confirmed by an increase of 34s values in dissolved so 4 2 from the infiltration area to the clay lignite horizon with an enrichment factor of 11 the very low doc concentrations of 1 5 mg c l in the clay lignite horizon with an organic matter content up to 50 c is probably caused by very low availability of organic matter to the processes of degradation and doc release demonstrated by extraction experiments with soc

the origin of thermal waters in the northeastern part of the eger rift czech republic abstract an investigation of the thermal waters in the usti nad labem area in the northeastern part of the eger rift has been carried out with the principal objective of determining their origin waters from geothermal reservoirs in the aquifers of the bohemian cretaceous basin bcb from depths of 240 to 616 m are exploited here for comparison thermal waters of the adjacent teplice spa area were also incorporated into the study results based on water chemistry and isotopes indicate mixing of groundwater from aquifers of the bcb with groundwater derived from underlying crystalline rocks of the erzgebirge mts unlike thermal waters in d cin which are of ca hco 3 type there are two types of thermal waters in usti nad labem na hco 3 cl so 4 type with high tds values and na ca hco 3 so 4 type with low tds values carbon isotope data speciation calculations and inverse geochemical modeling suggest a significant input of endogenous co 2 at usti nad labem in the case of high tds groundwaters besides co 2 input both silicate dissolution and cation exchange coupled with dissolution of carbonates may explain the origin of high tds thermal waters equally well this is a consequence of similar 13 c and 14 c values in endogenous co 2 and carbonates both sources have 14 c of 0 pmc endogenous co 2 13 c around 3 carbonates in the range from 5 to 3 v pdb the source of cl seems to be relict brine formed in tertiary lakes which infiltrated into the deep rift zone and is being flushed out the difference between high and low tds groundwaters in usti nad labem is caused by location of the high mineralization groundwater wells in co 2 emanation centers linked to channel like conduits this results in high dissolution rates of minerals and in different 13 c dic and 14 c dic fingerprints a combined 34 s and 18 o study of dissolved so 4 indicates multiple so 4 sources involving so 4 from relict brines and oxidation of h 2 s the study clearly demonstrates potential problems encountered at sites with multiple sources of c where several evolutionary groundwater scenarios are possible

on the origin and fluid content of some rare crustal xenoliths and their bearing on the structure and evolution of the crust beneath the bakony balaton highland volcanic field w hungary rarely occurring clinopyroxene plagioclase bearing felsic granulite and skarn xenoliths were studied from the mantle and crustal xenolith bearing alkaline basaltic and pyroclastic localities of the bakony balaton highland volcanic field w hungary geobarometry and geothermometry of the xenoliths made it possible to categorise them in three groups according to their depth of formation the first group formed in the lower crust together with mafic and metasedimentary granulites the second group represents magmatic intrusions of the middle crust and the third one comprises contact metamorphic rocks of relatively shallow origin the calculated pressure difference from the core and rim compositions of plagioclase and clinopyroxene as well as garnet breakdown reactions in some xenoliths show evidence for pressure decrease due to crustal thinning both in lower crustal and middle crustal xenoliths during formation of the pannonian basin fluid inclusion studies reveal the dominance of the co2 rich fluids in the whole crustal section in contrast with fluids found in mafic garnet bearing xenoliths crustal stratigraphy was constructed for the periods prior to the extension and after the extension on the basis of geobarometry and geophysical data on the basis of mineral stabilities and geothermo barometry we estimated that the pre extensional thickness of the lower and upper crust may have been 27 34 and 26 28 km respectively comparison of pre extensional and present day thickness of the lower and upper crust indicate that thinning affected both the lower and the upper portion of the crust but on a different scale the calculated thinning factors are between 2 25 and 3 4 for the lower crust and 1 3 1 56 for the upper crust

transport of mantle volatiles through the crust traced by seismically released fluids a natural experiment in the earthquake swarm area vogtland nw bohemia central europe abstract vogtland which is located on the czech german border near the crossing of the eger rift and the marianske lazn fault zone is characterised by co 2 rich mineral springs fed by a magmatic source and swarm earthquake activity the free gas of the eisenquelle mineral spring was studied weekly from april 1994 to june 1996 a period which included a quake swarm on december 4 and 5 1994 comprising approximately 500 individual events m local 2 2 co seismic shifts in he content after about a month as well as in the 13 c of co 2 and 3 he 4 he after about 220 days were resolved from seasonal background variations the he concentration shift is assumed to originate near the discharge whereas the isotopic shifts are probably caused by the addition of crustal fluids released by crushing rocks within the hypocentre from the distance of 14 km between the hypocentre to the mineral spring the transport velocity of the released crustal fluids was determined to be at least 50 m day such a high speed indicates gaseous fluid transport along channel like conduits rather than being predominantly controlled by dissolution in water using a simple mass balance it is shown that the amount of crustal fluids potentially released by seismic activity strongly exceeds that required for the observed shifts in 3 he 4 he and 13 c this fact along with the coincidence of both shifts supports the hypothesis that magmatic fluids occurring in mineral waters of the eisenquelle environs flush the hypocentral crustal block by means of advectional transport

use of isotope fractionation of sulfate sulfur and sulfate oxygen to assess bacterial desulfurication in a sandy aquifer abstract the unconfined aquifer of the fuhrberger feld consists of 20 30m sands and gravelly sands with unevenly distributed reduced sulfur compounds and small lignitic pebbles in vertical direction two hydrochemically different zones with specific solute transformations are present an upper portion with bacterial denitrification with reduced sulfur compounds as electron donors and a deeper portion with hydrochemical indications of reduction of the aqueous sulfate in the study area ten multilevel groundwater sampling wells were installed sampling and interpretation was based on a two dimensional vertical plane groundwater flownet and on the knowledge of the landuse upgradient of the multilevel wells the concentration and isotopic composition of the sulfate at the entrance into the zone of sulfate reduction is controlled by sulfate of groundwater recharge as well as sulfate formed during denitrification the recharge sulfate shows clear landuse specific differences in concentration and isotopic composition under arable land an average concentration of 60 mg so 4 l 1 with values of 34 s close to 3 cdt diablo meteorite standard canon and of 18 o about 8 standard mean ocean water smow was measured whereas under coniferous forest an average of 100 mg so 4 l 1 with 34 s 2 and 18 o 4 5 was found in the denitrification zone no significant sulfur isotope fractionation occurs during oxidation of reduced sulfur the oxygenisotopic composition of the newly formed sulfate denitrification sulfate depends on the 18 o content of nitrate acting as oxygen donor and on the 18 o content of groundwater in which the oxidation occurs under certain assumptions a 18 o 0 54 was calculated for the oxygen of the newly formed sulfate consequently with increasing sulfate concentrations i e with the admixture of denitrification sulfate a decrease of the 18 o values from about 8 to 2 was observed in the zone of sulfate reduction both the 34 s and 18 o values of the residual sulfate increase with decreasing sulfate concentrations thus proving the existence of bacterial reduction of the aqueous sulfate this sulfate reduction follows a rayleigh process with calculated enrichment factors of 34 9 7 for 34 s and 18 6 for 18 o respectively a plot of 34 s vs 18 o gives a good linear correlation with a slope close to 1 1 4 data on concentration and isotopic composition of sulfate and on the hydraulically derived groundwater age are used for kinetic considerations the results of a multilevel well for depths between 10 and 17m are given as an example the bacterial reduction can be considered as first order reaction with a half life between 75 and 100 years

lee wave resonances over double bell shaped obstacles lee wave resonance over double bell shaped obstacles is investigated through a series of idealized highresolution numerical simulations with the nonhydrostatic coupled ocean atmosphere mesoscale prediction system coamps model using a free slip lower boundary condition the profiles of wind speed and stability as well as terrain derive from observations of lee wave events over the sierra nevada and inyo mountains from the recently completed terrain induced rotor experiment t rex numerical experiments show that double bell shaped obstacles promote trapped lee waves that are in general shorter than those excited by an isolated ridge while the permissible trapped lee wave modes are determined by the upstream atmospheric structure primarily vertical wind shear the selected lee wave wavelengths for two obstacles that are close or equal in height are dictated by the discrete terrain spectrum and correspond to higher harmonics of the primary orographic wavelength which is equal to the ridge separation distance the exception is the smallest ridge separation distance examined one that corresponds to the owens valley width and is closest to the wavelength determined by the given upstream atmospheric structure for which the primary lee wave and orographic wavelengths were found to nearly coincide the influence two mountains exert on the overall lee wave field is found to persist at very large ridge separation distances for the nonlinear nonhydrostatic waves examined the ridge separation distance is found to exert a much stronger control over the lee wave wavelengths than the mountain half width positive and negative interferences of lee waves which can be detected through their imprint on wave drag and wave amplitudes were found to produce appreciable differences in the flow structure mainly over the downstream peak with negative interference characterized by a highly symmetric flow pattern leading to a low drag state

origin of co2 and carbonate veins in mantle derived xenoliths in the pannonian basin the origin and evolution of co2 inclusions and calcite veins in peridotite xenoliths of the pannonian basin hungary were investigated by means of petrographic investigation and stable isotope analyses the fluid inclusions recovered in paragenetic olivine and clinopyroxene belong to distinct populations type a texturally early inclusions with regular shapes often with negative crystal forms forming intragranular trails type b texturally late inclusions defining randomly oriented trails that reach grain boundaries type b inclusions are often associated with silicate melt type c inclusions stable carbon isotope compositions in inclusion hosted co2 were obtained by vacuum crushing followed by conventional dual inlet as well as continuous flow mass spectrometry in order to eliminate possible lab artifacts olivines clino and orthopyroxenes of the host peridotite have oxygen isotope compositions from 5 3 to 6 0 relative to v smow without any relationship with xenolith texture some of the xenoliths contained calcite in various forms veins and infillings in silicate globules in veins secondary carbonate veins filling cracks and metasomatic veins with diffuse margins the former two carbonate types have 13c values around 13 relative to v pdb and low sr contents 0 5 wt whereas the third type veins with high temperature metasomatic features have a 13c value of 5 0 and high sr contents up to 3 4 wt in spite of the mantle like 13c value and the unusually high sr content typical for mantle derived carbonate trace element compositions have proven a crustal origin this observation supports the conclusions of earlier studies that the carbonate melt droplets found on peridotite xenoliths in the alkaline basalts represent mobilized sedimentary carbonate the large 13c range and the 12c enrichment in the carbonates can be attributed to devolatilization of the migrating carbonate or infiltration of surficial fluids containing 12c rich dissolved carbon carbon isotope compositions of inclusion hosted co2 range from 17 8 to 4 8 relative to v pdb with no relation to the amount of co2 released by vacuum crushing low 13c values measured by stepwise heating under vacuum suggest that the carbon component is pristine and not related to surficial contamination and that primary mantle fluids with 13c values around 5 were at least partly preserved in the xenoliths tectonic reworking and heating by the basaltic magma resulted in partial co2 release and local 13c depletion

upstream propagating wave modes in moist and dry flow over topography abstractprevious studies have observed upstream propagating modes in two dimensional numerical simulations of idealized flow over topography with moist nearly neutral conditions in the troposphere topped by a stable stratosphere the generation and propagation mechanisms for these modes were attributed to localized and dramatic changes in stability induced by the desaturation of the flow impinging on the mountain in the present paper it is shown that these modes are transient upstream propagating gravity waves which are a fundamental feature of both moist and dry flow over topography of a two layer troposphere stratosphere atmospheric profile impulsively started from rest the mode selection and propagation speeds of these transient waves are highly dependent on the tropospheric stability as well as the wind speed and tropopause depth in the moist case these modes appear to propagate according to an effective static stability that is intermediate to the normal dry stability and the lower moist stabi

the geochemistry and origin of fluids in the carbonate structure of the hranice karst with the world s deepest flooded cave of the hranicka abyss czech republic abstract the origin of fluids in the hranice karst containing the deepest flooded abyss in the world has been investigated using hydrogeological hydrogeochemical and isotopic data at least a part of the co2 gas originates in the mantle as indicated by very enriched 13c dic values and from existing he isotope analyses the origin of groundwater in the karstic aquifer which is exploited at the teplice nad becvou spa is meteoric with a recharge area about 200 m above the becva river valley as indicated by depleted values of 2h and 18o compared to the river water based on detectable tritium the groundwater is from 20 to 50 years old water in the hranicka abyss and in the zbrasov aragonite caves is a mixture of carbonate aquifer groundwater with the river and or shallow groundwater comprising variable proportions of both end members water in death cave lake seems to be affected by agriculture contaminated shallow groundwater as indicated by increased nitrate concentration inverse geochemical modeling of aquifer geochemistry suggested two scenarios 1 reaction of mg rich calcite with deep hypogenic co2 about 30 mmol l plus dissolution of trace amounts of halite and sylvite and cation exchange 2 reaction of mg depleted calcite and mg silicate talc as a source of mg together with deep co2 both scenarios were calibrated using 13c dic values and gave satisfactory results a conceptual model of the site has been developed which includes a gravity driven flow system where meteoric water which has recharged in the surrounding uplands is heated at depth and acquires large amounts of hypogenic co2 which preferentially dissolves mg carbonates along the pre existing tectonic features the miocene transgression followed by the later incision of the becva valley played an important role in groundwater circulation and the origin of fluids

observations of nonclassical frontal propagation and frontally forced gravity waves adjacent to steep topography through the integrated analysis of remote sensing and in situ data taken along the front range of colorado this study describes the interactions that occurred between a leeside arctic front and topographically modulated flows these interactions resulted in nonclassical frontal behavior and structure across northeastern colorado the shallow arctic front initially advanced southwestward toward the front range foothills before retreating eastward then a secondary surge of arctic air migrated westward into the foothills during its initial southwestward advance the front exhibited obstacle like density current characteristics its initial advance was interrupted by strong downslope northwesterly flow associated with a high amplitude mountain wave downstream of the continental divide and by a temporal decrease in the density contrast across the front due to diurnal heating in the cold air and weak cold advection in the warm air the direction and depth of flow within the arctic air also influenced the frontal propagation the shallow obstacle like front actively generated both vertically propagating and vertically trapped gravity waves as it advanced into the downslope northwesterly flow resulting in midtropospheric lenticular wave clouds aloft that tracked with the front because the front entered a region where strong downslope winds and mountain waves extended downstream over the high plains the wave field in northeastern colorado included both frontally forced and true mountain forced gravity waves a sequence of scorer parameter profiles calculated from hourly observations reveals a sharp contrast between the prefrontal and postfrontal wave environments consequently analytic resonant wave mode calculations based on the scorer parameter profiles reveal that the waves supported in the postfrontal regime differed markedly from those supported in the prefrontal environment this result is consistent with wind profiler observations that showed the amplitude of vertical motions decreasing substantially through 16 km above mean sea level msl after the shallow frontal passage

sulfur cycling in an acid mining lake and its vicinity in lusatia germany the sulfur cycle plays a key role in the hydrochemical development of lignite and coal mining districts which are often characterized by acid mine drainage identification of sulfur sources and transformations is essential if we are to understand the current status of acid lakes and propose successful remediation strategies we utilized stable isotope 34ssulfate 18osulfate 34sdissolved sulfide 18owater and hydrochemical data of lake and groundwater samples as well as the concentrations and isotope ratios of various sedimentary sulfur compounds acid soluble sulfate ass acid volatile sulfur avs chromium reducible sulfur crs in aquifer and lake sediments for assessing the biogeochemical sulfur cycle in a lusatian acidic mining lake ml111 and the surrounding area pyrite oxidation is the dominant source of sulfate and iron in the two aquifers west and east of mining lake ml111 concentration and isotope data for dissolved sulfate suggest that bacterial dissimilatory sulfate reduction became an increasingly important process in the flow direction of the western aquifer thereby improving water quality in contrast bacterial sulfate reduction was only of local importance in the dump aquifer on the eastern side of the lake oxygen isotope ratios of the lake water sulfate and mass and isotope balances demonstrate that 80 of the sulfate in mining lake ml111 is derived via groundwater influx from the dump aquifer with the remainder contributed by the western aquifer in lake pyrite oxidation or bacterial sulfate reduction in the water column are insignificant the latter process is restricted to the monimolimnion which represents less than 1 of the lake volume hence the potential for natural generation of alkalinity by bacterial dissimilatory sulfate reduction is presently low for successful remediation of ml111 it is essential to reduce significantly the continuous input of sulfate and acidity from inflowing dump groundwater

14c dating of gorleben groundwater previous attempts to apply 14c for dating of groundwater in the gorleben aquifer system has given results with conflicting 3h and stable isotope data and hydrological estimates 14c model ages of 1 10 ka have been found for 3h containing recharge water up to 31 ka for groundwater with holocene stable isotope signatures and 6 10 ka for groundwater at 35 m depth in this paper it is shown that the reasons are assumption of to high 14c concentration in recharge groundwater and not correcting for the influence of 14c dilution by dissolved inorganic c dic from microbiologically mediated mineralization of organic components in deep sediments to overcome these difficulties a new approach is applied evaluating the site specific 14c source term including the influence of nuclear atmospheric testing and the already previously used overall dilution of dic closed system conditions are assumed and no isotopic fractionation is considered for most of the groundwaters the 14c ages achieved by the present method are in agreement with 3h stable isotopes and hydrological estimates it is shown that down to approximately 140 m depth no 14c decay can be detected situations are also discussed either where the 14c method is not applicable shallow peat bog like groundwater or does not yield reliable groundwater ages brines at 200 m depth