rare earth abundance patterns in ferromanganese concretions from the gulf of bothnia and the barents sea abstract ferromanganese concretions from the svalbard shelf in the barents sea show slightly convex shale normalized ree patterns with no eu anomalies concretions from the gulf of bothnia northern part of the baltic sea exhibit an enrichment of light ree and negative eu anomalies this difference is interpreted as a consequence of different conveyor mechanisms of the ree to the sediment it is suggested that dissolving biogenic debris contributes to the convex pattern obtained in the barents sea whereas an inorganic suspended fraction with scavenged ree is the main carrier in the gulf of bothnia during oxic diagenesis in the sediment the scavenged ree are set free into the porewater and contribute to the distribution pattern in concretions found in the gulf of bothnia small mn rich spheroidal concretions are enriched two to five times in ree compared to average shale whereas mn poor flat concretions are low in ree specific surface area of the concretion and the depth of burial in the oxidized surface sediment are two factors that strongly affect the enrichment of the ree weak ce anomalies are present in the analysed concretions and a redox level dependence is seen

a bayesian approach for inversion of hydraulic tomographic data 1 hydraulic tomography is a promising methodology that shows the potential to map subsurface hydraulic properties at an unprecedented level of detail by interpreting a suite of hydraulic tests in the present work we apply the hydraulic tomography concept to a multiple pulse multiple receiver mpmr cross well configuration which consists of two boreholes subdivided into intervals by packers a short pressure or flow pulse is applied sequentially to all the intervals and for each perturbation the transient heads are recorded at the remaining intervals the resulting tomograms are inverted within the bayesian framework by using the pilot point approach in addition to the values of the hydraulic conductivity at the pilot points we assume that the stochastic parameters of the spatial variability model the structural parameters are unknown using synthetic two dimensional and three dimensional examples we demonstrate the effectiveness of the mpmr configuration and the inversion procedure for characterizing the spatial variability of the hydraulic conductivity with limited or no prior information we observed that increasing the number of source points the locations at which the pulse is alternatively applied provides more details on the spatial variability and that the parameters of the hydrogeological model of spatial variability are inferred with an acceptable although variable level of accuracy in particular the theoretical variance of the log conductivity is estimated with large errors while the estimate of the anisotropic integral scales depends on the distance between the boreholes inversion preserves the overall spatial pattern of hydraulic conductivity although low conductivity values are less connected in the inferred than in the true conductivity fields

characterization of the hydrogeological experimental site of poitiers france by stochastic well testing analysis summary we assess the applicability and performance of the stochastic well testing methodology of neuman et al neuman s p guadagnini a riva m 2004 type curve estimation of statistical heterogeneity water resources research 40 w04201 doi 10 1029 2003wr002405 neuman s p blattstein a riva m tartakovsky d m guadagnini a ptak t 2007 type curve interpretation of late time pumping test data in randomly heterogeneous aquifers water resources research 43 w10421 doi 10 1029 2007wr005871 to provide a geostatistical characterization of the transmissivity distribution of a heterogeneous aquifer we use cross hole pumping test information also referred to as interference testing collected during two extensive and detailed experimental campaigns performed in 2004 and 2005 in a limestone aquifer constituting the hydrogeological experimental site hes of poitiers france the methodology we use is based on stochastic type curves of mean drawdown and associated variance and is aimed at revisiting the results of routine pumping tests within a stochastic framework it allows estimating the geometric mean integral scale and variance of local log transmissivities on the basis of quasi steady state head data when a randomly heterogeneous confined aquifer is pumped at a constant rate the results are discussed by comparison against a previous deterministic analyses performed at the site using the same dataset and b information obtained by geostatistical analysis of existing geophysical data the estimated values of integral scales and variance of log transmissivity are viewed in light of multiscale theories which conceptualize the heterogeneity of porous and fractured systems as hierarchical random processes distributed across a multiplicity of scales the scale dependence observed for the estimated variogram parameters of log transmissivity at the hes site is consistent with the behavior of published worldwide data

arsenic regeneration from estuarine sediments of the bothnian bay sweden abstract sediments of the bothnian bay between northern sweden and northern finland are contaminated by as giving rise to concentrations in the percent range the enclosure of a sediment and bottom water by benthic chambers resulted in chemical reduction of the water and the oxidized sediment surface layer and a flux of reduced as from the feooh phase of the sediment the release of as could be described by zero or pseudo zero order reaction kinetics the measured flux of as into the water at 20 c was 2 1 mg m 2 day 1 as

flow bearing structures of fractured rocks insights from hydraulic property scalings revealed by a pumping test abstract a long duration pumping test conducted over 151 days in a fractured sandstone and shale formation displays a nonstandard drawdown response and anomalous pressure diffusion which cannot be properly interpreted using existing frameworks e g homogeneous double porosity boundary conditions and fractal models an alternative framework with simple geometry and more complex hydraulic properties is thus proposed to interpret such kind of drawdown responses the analytical development allows first to demonstrate all scaling relations in this interpretation framework then and most importantly the multi scale hydraulic test provides consistent scalings of transmissivity t to storativity s over distances ranging from 83 to 383 m in a faulted area drawdown analysis in several monitoring wells shows persistent decrease of transmissivity in highly channelized fracture flow structures in one structure the cubic dependency of transmissivity to storativity identifies a well defined fault and also demonstrates the validity of poiseuille flow at a scale rarely investigated in the other structure the linear dependency of transmissivity to storativity indicates that the flow bearing structure is the surrounding fracture network well designed pumping tests combined with scaling analysis driven by geological evidence thus provide essential information on flow bearing structures for site characterization and modeling tasks at least for moderate to low permeable fractured rocks the scaling of transmissivity to storativity appears to be more informative than any separate interpretation of hydraulic property scaling exponents

assessing radial transmissivity variation in heterogeneous aquifers using analytical techniques pumping tests are one of the most commonly used in situ testing techniques for assessing aquifer hydraulic properties numerous researches have been conducted to predict the effects of aquifer heterogeneity on the groundwater levels during pumping tests the objectives of the present work were as follows 1 to predict drawdown conditions and to estimate aquifer properties during pumping tests undertaken in radially symmetric heterogeneous aquifers and 2 to identify a method for assessing the transmissivity field along the radial coordinate in radially symmetric and fully heterogeneous transmissivity fields the first objective was achieved by expanding an existing analytical drawdown formulation that was valid for a radially symmetric confined aquifer with two concentric zones around the pumping well to an n concentric zone confined aquifer having a constant transmissivity value within each zone the formulation was evaluated for aquifers with three and four concentric zones to assess the effects of the transmissivity field on the drawdown conditions the specific conditions under which aquifer properties could be identified using traditional methods of analysis were also evaluated the second objective was achieved by implementing the inverse solution algorithm isa which was developed for petroleum reservoirs to groundwater aquifer settings the results showed that the drawdown values are influenced by a volumetric integral of a weighting function and the transmissivity field within the cone of depression the weighting function migrates in tandem with the expanding cone of depression the ability of the isa to predict radially symmetric and log normally distributed transmissivity fields was assessed against analytical and numerical benchmarks the results of this investigation indicated that the isa method is a viable technique for evaluating the radial transmissivity variations of heterogeneous aquifer settings copyright 2013 john wiley sons ltd

stochastic estimation of hydraulic transmissivity fields using flow connectivity indicator data this is the peer reviewed version of the following article freixas g d fernandez garcia and x sanchez vila 2017 stochastic estimation of hydraulic transmissivity fields using flow connectivity indicator data water resour res 53 602 618 doi 10 1002 2015wr018507 which has been published in final form at http onlinelibrary wiley com doi 10 1002 2015wr018507 abstract this article may be used for non commercial purposes in accordance with wiley terms and conditions for self archiving

influence of heterogeneity on the interpretation of pumping test data in leaky aquifers 1 pumping tests are routinely interpreted from the analysis of drawdown data and their derivatives these interpretations result in a small number of apparent parameter values which lump the underlying heterogeneous structure of the aquifer key questions in such interpretations are 1 what is the physical meaning of those lumped parameters and 2 whether it is possible to infer some information about the spatial variability of the hydraulic parameters the system analyzed in this paper consists of an aquifer separated from a second recharging aquifer by means of an aquitard the natural log transforms of the transmissivity ln t and the vertical conductance of the aquitard ln c are modeled as two independent second order stationary spatial random functions srfs the monte carlo approach is used to simulate the time dependent drawdown at a suite of observation points for different values of the statistical parameters defining the srfs drawdown data at each observation point are independently used to estimate hydraulic parameters using three existing methods 1 the inflection point method 2 curve fitting and 3 the double inflection point method the resulting estimated parameters are shown to be space dependent and vary with the interpretation method since each method gives different emphasis to different parts of the time drawdown data moreover the heterogeneity in the pumped aquifer or the aquitard influences the estimates in distinct manners finally we show that by combining the parameter estimates obtained from the different analysis procedures information about the heterogeneity of the leaky aquifer system may be inferred

temporal variations in dissolved and suspended iron and manganese in the kalix river northern sweden abstract particulate and dissolved fe and mn were measured once a week from may to september 1982 in the kalix river north sweden during winter baseflow the dissolved fe concentration was 450 g l 1 early snow melt discharge increased the concentration slightly but during springflood maximum the concentration decreased to a minimum value of 60 g l 1 in mid july particulate matter in the kalix river is dominated by fe which ranges between 14 and 38 of the ashed suspended load 70 80 of the total fe load being retained by 0 45 m filters approximately 10 of particulate fe can be accounted for by a detrital phase the particulate fe al ratio showed a mean value of 6 5 which is more than ten times the ratio in mean world river particulate fe showed a peak during early snowmelt and decreased during maximum discharge similar to dissolved fe dissolved mn concentrations ranged from 1 1 to 53 4 m l 1 with a mean value of 11 2 12 4 g l 1 whereas particulate mn ranged from 3 1 ti 18 2 g l 1 with a mean concentration of 10 6 4 9 g l 1 during may and june most mn was transported in the dissolved phase whereas in july and august the particulate fraction dominated there was a drastic increase in non detrital particulate mn with a concomitant decrease in the dissolved fraction in early july with peak values in mid july and early august the decrease in dissolved mn and increase of particulate mn is probably the consequence of two processes namely addition of non detrital particulate mn to the river possibly from lakes and transformation of dissolved mn to a particulate phase within the river a combination of increased ph temperature and particulate mn triggered the precipitation of dissolved mn although the significance of each factor can not be evaluated from this study

geochemistry of manganese in the kalix river northern sweden dissolved and suspended mn in the kalix river northern sweden were measured weekly over a period of eighteen months during the same period four lakes in the kalix catchment were sampled at their outlets and in vertical profiles within the lakes together with a stream draining a series of mires with shallow lakes snow melting in mid may increased the dissolved mn concentration in the river tenfold compared with a concentration of 5 g l 1 during the winter discharge january to april we suggest that the increase was caused by mn rich mire water mixing with melting snow and being transported to the river large concentrations of dissolved mn built up in the hypolimnion of the lakes studied during the icecovered period break up of the ice and spring overturn in june increased the dissolved mn concentration tenfold in lake discharge and a concomitant peak in the dissolved mn concentration was observed in the river lake derived mn was the dominant source for mn in the river during this time suspended mn in the river was hosted mainly in detrital particles during flood in may in mid june non detrital suspended mn started to accumulate and reached a maximum in late july and early august the mnal ratio was 25 times higher during this period than during flood in may suggesting the precipitation of an mn oxyhydroxide phase the precipitation of the non detrital mn rich phase was correlated in time with increased temperature increased ph and increased concentration of suspended biogenic particles the precipitation of dissolved mn was biologically mediated sedimentation and mineralisation of the non detrital mn phase in river and lake sediments resulted in a steady increase of the dissolved mn concentration in the river water during autumn

trace element cycling in a subterranean estuary part 1 geochemistry of the permeable sediments abstract subterranean estuaries are characterized by the mixing of terrestrially derived groundwater and seawater in a coastal aquifer subterranean estuaries like their river water seawater counterparts on the surface of the earth represent a major but less visible hydrological and geochemical interface between the continents and the ocean this article is the first in a two part series on the biogeochemistry of the subterranean estuary at the head of waquoit bay cape cod ma usa the pore water distributions of salinity fe and mn establish the salt and redox framework of this subterranean estuary the biogeochemistry of fe mn p ba u and th will be addressed from the perspective of the sediment composition a second article will focus on the groundwater and pore water chemistries of fe mn u and ba three sediment cores were collected from the head of waquoit bay where the coastal aquifer consists of permeable sandy sediment a selective dissolution method was used to measure the concentrations of p ba u and th that are associated with amorphous hydr oxides of iron and manganese and crystalline fe and mn hydr oxides the deeper sections of the cores are characterized by large amounts of iron hydr oxides that are precipitated onto organic c poor quartz sand from high salinity pore waters rich in dissolved ferrous iron unlike fe hydr oxides which increase with depth the mn hydr oxides display midcore maxima this type of vertical stratification is consistent with redox controlled diagenesis in which mn hydr oxides are formed at shallower depths than iron hydr oxides p and th are enriched in the deep sections of the cores consistent with their well documented affinity for fe hydr oxides in contrast the downcore distribution of ba especially in core 3 more closely tracks the concentration of mn hydr oxides even though mn hydr oxides are 200 300 times less abundant than fe hydr oxides in the cores mn hydr oxides are known to have an affinity for ba which is many orders of magnitude greater than iron hydr oxides hence the downcore distribution of ba in fe hydr oxide rich sediments is most probably controlled by the presence of mn hydr oxides u is enriched in the upper zones of the cores consistent with the formation of highly reducing near surface sediments in the intertidal zone at the head of the bay hence the recirculation of seawater through this type of subterranean estuary coupled with the abiotic and or biotic reduction of soluble u vi to insoluble u iv leads to the sediments acting as a oceanic net sink of u these results highlight the importance of permeable sediments as hosts to a wide range of biogeochemical reactions which may be impacting geochemical budgets on scales ranging from coastal aquifers to the continental shelf

characterization of aquifer heterogeneity using transient hydraulic tomography 1 hydraulic tomography is a cost effective technique for characterizing the heterogeneity of hydraulic parameters in the subsurface during hydraulic tomography surveys a large number of hydraulic heads i e aquifer responses are collected from a series of pumping or injection tests in an aquifer these responses are then used to interpret the spatial distribution of hydraulic parameters of the aquifer using inverse modeling in this study we developed an efficient sequential successive linear estimator ssle for interpreting data from transient hydraulic tomography to estimate three dimensional hydraulic conductivity and specific storage fields of aquifers we first explored this estimator for transient hydraulic tomography in a hypothetical one dimensional aquifer results show that during a pumping test transient heads are highly correlated with specific storage at early time but with hydraulic conductivity at late time therefore reliable estimates of both hydraulic conductivity and specific storage must exploit the head data at both early and late times our study also shows that the transient heads are highly correlated over time implying only infrequent head measurements are needed during the estimation applying this sampling strategy to a well posed problem we show that our ssle can produce accurate estimates of both hydraulic conductivity and specific storage fields the benefit of hydraulic tomography for ill posed problems is then demonstrated finally to affirm the robustness of our ssle approach we apply the ssle approach to a hypothetical three dimensional heterogeneous aquifer

early diagenesis of arsenic in sediments of the kalix river estuary northern sweden solid phase as fe mn s and al and pore water total as fe mn and s have been determined for two cores from the kalix river estuary at the same station the depositional flux of arsenic was measured sediment traps fe iii oxides persist in the anoxic zone of the sediment and act as a carrier for arsenic down to depths of 10 15 cm the release of arsenic into the pore water is controlled by the reduction dissolution of these oxides as a result internal cycling of arsenic i e upward diffusion in pore water re adsorption onto fe iii oxides in the oxidized surface layer and reburial occurs in the uppermost 10 15 cm at the base of the arsenic cycling zone solid phase arsenic maxima 160 170 g g 1 of probable diagenetic origin occur the quantity of arsenic diffusing back towards the oxidized surface layer 2 2 g cm 2 yr 1 as is close to 75 of the quantity of arsenic being deposited due to sedimentation 2 9 g cm 2 yr 1 as however a mass balance for the surface layer indicates that re adsorption of arsenic onto fe iii oxides may effectively prevent diffusion of dissolved arsenic back into the overlying water column it is concluded that the interpretation of sedimentary arsenic profiles may be severely complicated due to post depositional migration of arsenic

geochemistry and origin of ferromanganese concretions in the gulf of bothnia abstract ferromanganese concretions cover large areas of the gulf of bothnia they are flat to well rounded the rounded ones being richer in oxyhydroxides of iron and manganese rounded and ellipsoidal nodules particularly those in the northern gulf of bothnia are richest in mn ni ba and cu which probably coexist in a mn oxyhydroxide phase flat nodules are enriched in fe p rare earths and as probably associated with an fe oxy hydroxide component aluminum v cr and ti occur in still another phase the sediments of the gulf generally consist of a 10 50 mm thick layer of oxidized surface sediment enriched in mn ba p and ni lying on top of reduced sediments which are diagenetically depleted in these elements the remobilized elements have redeposited in the nodules but this process cannot explain the origin of all the nodular material some released mn ba and ni furthermore enter into suspended phases which eventually leave the baltic sea the economic value of the nodules in the gulf of bothnia is probably limited at present

estimating transmissivity from single well pumping tests in heterogeneous aquifers although aquifers are naturally heterogeneous the interpretation of pumping tests is commonly performed under the assumption of aquifer homogeneity this yields interpreted hydraulic parameters averaged over a domain of uncertain extent which disguises their relation to the underlying heterogeneity in this study we numerically investigate the sensitivity of the transient drawdown at the pumping well to nonuniform distributions of transmissivity in confined aquifers frechet kernels and their time derivative are used to estimate two spatially averaged transmissivities denoted the equivalent and interpreted transmissivity teq and tin respectively for the case of single well pumping tests interrelating teq and tin is achieved by modeling tin in terms of a distance dependent radially heterogeneous field in weakly heterogeneous aquifers teq approximates tpw the local transmissivity at the pumped well with increasing degree of heterogeneity teq deviates from tpw as pumping propagates tin starts at tpw approaching the spatial geometric mean of transmissivity during late pumping times limits of the proposed spatial weighting functions are investigated by treating the interpreted storativity sest as an indicator for flow connectivity it is shown numerically that the spatial weights for teq and tin agree well to the underlying heterogeneity if sest 1 finally implications for applying the concepts of teq and tin to heterogeneous domains and for real world applications are discussed it is found that time dependent spatial averages of tin agree well with estimates of the interpreted transmissivity from the continuous derivation method

oxygen penetration and subsequent reactions in flooded sulphidic mine tailings a study at stekenjokk northern sweden abstract a study of o2 penetration and pore water geochemistry of the flooded tailings at stekenjokk has been performed the results show that there is a diffusion of elements from the tailings pore water to the overlying water the presence of elements such as ca mg s si ba and sr are likely the result of diffusion of older process water trapped in the tailings oxygen concentrations in the tailings measured with microelectrodes show that there is o2 available down to 16 to 17 mm depth in the tailings pore water analyses show that there are subsurface maxima for the elements cu zn ni co and cd at depths of 0 25 to 2 75 cm the highest concentrations of almost all elements were found where previously oxidised material was deposited before the flooding lower ph is measured in the uppermost part of the tailings compared with the pond water and the tailings pore water at depth oxidation of sulphides in the uppermost part of the tailings is probably occurring a decrease in oxidation rate can be expected in the future due to deposition of organic material at the tailings surface flooding seems to be an efficient remediation method at stekenjokk

geochemistry of ferromanganese concretions in the barents sea abstract ferromanganese concretions from ten stations in the barents sea have been analysed for 24 elements the deposits occur as discoidal and flat concretions and as coatings in the latter case on lithified or detrital material or as extensive pavements on the svalbard shelf the concretions are compositionally similar to baltic concretions but differ considerably from deep ocean nodules particularly in cu ni and co contents statistical analyses reveal distinct correlations between mn na ba ni and cu the mn rich coatings showed enrichment of mo zn and possibly co in a mn phase the iron phase holds high concretions of p and as two iron rich concretions with high contents of p ca sr y yb and la were found east and northeast of spitsbergen banken probably indicating upwelling of nutrient rich cold polar water along the svalbard shelf

applicability of method to estimate transmissivity based on yield drawdown analysis in mountainous fractured rock aquifers a case study in taiwan abstract the observation of yield drawdown response in the course of pumping test as well as its derived application for aquifer characterization is an essential practice in a geotechnical investigation on the basis of that for providing a reasonable estimate of aquifer transmissivity on site a number of empirical models have therefore been proposed yet the majority of previous studies are conducted based on investigations at homogeneous alluvial plain very few particularly in the case of taiwan are carried out focusing on mountainous fractured rock aquifers aiming to address this problem the observation data of 53 pumping tests obtained from a multi years in situ geological investigation program are analyzed and the applicability of empirical log log linear relationship between t and q s is examined our analysis reveals that the yield drawdown responses derived from different geologic formations are quantitatively distinct and those empirical rules derived from the alluvial landform should be used with care when applying in mountainous fractured rock aquifers based on the analysis of statistical results in our study with a systematic investigation and clarification of the q s relationship in advance a satisfactory and cost effective solution is obtained

a new parameter estimation procedure for pumping test analysis using a radial basis function collocation method theoretical well function formulations in confined aquifer leaky or unconfined aquifer types were originally developed to analyze the transient response of the ideal aquifer settings i e homogeneous isotropic medium constant withdrawal rate negligible well bore storage and skin effects etc any deviations from the idealization of the aquifer settings inversely affect the estimation performance which may result in an unrealistic interpretation of pump test analysis a radial basis function collocation method rbfcm based estimation procedure was proposed to elaborate the aquifer parameters in homogeneous and heterogeneous porous medium in the present work the potential drawbacks of the classical curve matching techniques and the derivative based estimation methods have been evaded without dense computation efforts using rbfcm the proposed method as a default application procedure requires no additional parameter no initial guess no interpolation or any complicated derivative calculation to assess the aquifer parameters the suggested approach therefore provides a greater degree of flexibility in the estimation and the same level of accuracy when compared to the existing methods used in hydrology practice this study also reveals the use of proposed method as a diagnostic tool to identify aquifer character by tracking the aquifer parameter variation in time as well as the potential use of rbfcm as an inverse solution technique in the hydrogeology problems

inferring spatial distribution of the radially integrated transmissivity from pumping tests in heterogeneous confined aquifers 1 hydrologists routinely analyze pumping test data using conventional interpretation methods that are based on the assumption of homogeneity and that consequently yield single estimates of representative flow parameters however natural subsurface formations are intrinsically heterogeneous and hence the flow parameters influencing the drawdown vary as the cone of depression expands in time in this paper a novel procedure for the analysis of pumping tests in heterogeneous confined aquifers is developed we assume that a given heterogeneous aquifer can be represented by a homogeneous system whose flow parameters evolve in time as the pumping test progresses at any point in time the interpreted flow parameters are estimated using the ratio of the drawdown and its derivative observed at that particular time the procedure is repeated for all times yielding time dependent estimates of transmissivity ti t and storativity si t based on the analysis of the sensitivity of drawdown to inhomogeneities in the t field the time dependent interpreted transmissivity values are found to be a good estimate of tg r the geometric mean of the transmissivity values encompassed within a progressively increasing radius r from the well the procedure is illustrated for gaussian heterogeneous fields with ln t variances up to a value of 2 the impact of the separation distance between the pumping well and observation point on data interpretation is discussed the results show that information about the spatial variability of the transmissivity field can be inferred from time drawdown data collected at a single observation point

thallium isotope variations in seawater and hydrogenetic diagenetic and hydrothermal ferromanganese deposits results are presented for the first in depth investigation of tl isotope variations in marine materials the tl isotopic measurements were conducted by multiple collector inductively coupled plasma mass spectrometry for a comprehensive suite of hydrogenetic ferromanganese crusts diagenetic fe mn nodules hydrothermal manganese deposits and seawater samples the natural variability of tl isotope compositions in these samples exceeds the analytical reproducibility 0 05 by more than a factor of 40 hydrogenetic fe mn crusts have 205tl of 10 to 14 whereas seawater is characterized by values as low as 8 205tl represents the deviation of the 205tl 203tl ratio of a sample from the nist srm 997 tl isotope standard in parts per 104 this 2 difference in isotope composition is thought to result from the isotope fractionation that accompanies the adsorption of tl onto ferromanganese particles an equilibrium fractionation factor of 1 0021 is calculated for this process ferromanganese nodules and hydrothermal manganese deposits have variable tl isotope compositions that range between the values obtained for seawater and hydrogenetic fe mn crusts the variability in 205tl in diagenetic nodules appears to be caused by the adsorption of tl from pore fluids which act as a closed system reservoir with a tl isotope composition that is inferred to be similar to seawater nodules with 205tl values similar to seawater are found if the scavenging of tl is nearly quantitative hydrothermal manganese deposits display a positive correlation between 205tl and mn fe this trend is thought to be due to the derivation of tl from distinct hydrothermal sources deposits with low mn fe ratios and low 205tl are produced by the adsorption of tl from fluids that are sampled close to hydrothermal sources such fluids have low mn fe ratios and relatively high temperatures such that only minor isotope fractionation occurs during adsorption hydrothermal manganese deposits with high mn fe and high 205tl are generated by scavenging of tl from colder more distal hydrothermal fluids under such conditions adsorption is associated with significant isotope fractionation and this produces deposits with higher 205tl values coupled with high mn fe

steady state hydraulic tomography in a laboratory aquifer with deterministic heterogeneity multi method and multiscale validation of hydraulic conductivity tomograms summary hydraulic tomography potentially is a viable technology that facilitates subsurface imaging of hydraulic heterogeneity to date a comprehensive validation of hydraulic tomography has not been done either at the laboratory or field scales the main objective of this paper is to examine the accuracy of hydraulic conductivity k tomograms obtained from the steady state hydraulic tomography algorithm of yeh t c j liu s 2000 hydraulic tomography development of a new aquifer test method water resources research 36 2095 2105 we first obtain a reference k tomogram through the inversion of synthetic cross hole test data generated through numerical simulations the purpose of reference k tomogram generation is to examine the ability of the algorithm to image the heterogeneity pattern under optimal conditions without experimental errors and with full control of forcing functions initial and boundary conditions as well as source sink terms parallel to the generation of synthetic data we conduct hydraulic tests at multiple scales in a laboratory aquifer with deterministic heterogeneity to generate data that are used to validate k tomograms from hydraulic tomography measurements include multiple k estimates from core slug single hole and cross hole tests as well as several unidirectional flow through experiments conducted on the sandbox under steady state conditions validation of k tomograms involved a multi method and multiscale approach proposed herein which include 1 visual comparisons of k tomograms to the true sand distributions and the reference k tomogram 2 testing the ability of the k tomogram to predict the hydraulic head distribution of an independent cross hole test not used in the computation of the k tomogram 3 comparison of the conditional mean and variance of local k from the k tomograms to the sample mean and variance of results from other measurements 4 comparison of local k values from k tomograms to those from the reference k tomogram and 5 comparison of local k values from k tomograms to those obtained from cores and single hole tests the multi method and multiscale validation approach proposed herein further illustrates the robustness of steady state hydraulic tomography in subsurface heterogeneity delineation

lead isotopes as tracers of lead pollution from various sources an example from northern sweden abstract the surface sediments in the central bothnian bay are contaminated with anthropogenic pb preindustrial concentrations range from 9 to 43 ppm but the surface sediments contain up to 158 ppm pb possible sources of the pb pollution are anthropogenic atmospheric pb where the main pb source is combustion of gasoline and ore from the laisvall mine which is processed in the smelter ronnskars verken on the coast of bothnian bay because the pb isotope composition of these possible sources are known an attempt was made to trace the origin of the anthropogenic pb in bothnian bay by studying the pb isotope composition of sediments the results show unequivocally that laisvall pb is not the source of the pollution the enrichment of pb in surface sediments is caused by atmospheric deposition of pb additives from gasoline lead emitted from ronnskarsverken is deposited relatively close to the smelter and has not reached central bothnian bay in traceable amounts

iron and manganese layering in recent sediments in the gulf of bothnia abstract the oxidized surface layer of recent soft sediments in the gulf of bothnia northern part of the baltic sea has been investigated distinct stratification of fe and mn is observed with up to five different horizons in well developed profiles these layered top sediments although not previously noticed occur extensively in the gulf of bothnia there is a close association of mn and ni ba zn and cu whereas p ca and sr are associated with fe high dissolved fe and mn contents coupled with a strong redox gradient are recorded in the interstitial waters formation of these layers is linked to varying redox conditions fe and mn tend to be dissolved under reducing conditions to migrate upwards and to reprecipitate as oxyhydroxides along favourable redox horizons reaching oxidizing conditions fe precipitates prior to mn and is always found below the mnrich strata the character of the oxidized zone is quite different in the two sub basins of the gulf of bothnia mn rich horizons together with spherical mn rich nodules are frequently found in the bothnian bay while in the bothnian sea mostly fe rich layers are present together with abundant fe rich flat concretions this difference is interpreted as being due to a lower redox level in the bothnian sea

a stress province boundary and tractions on the north american plate stress provinces characterized by nearly constant directions and relative magnitudes of horizontal principal stresses are potentially informative of the forces acting on a lithosphere plate this applies most strongly to stress provinces which occupy a large part of a plate such as the mid continent stress province of north america identified by zoback and zoback1 we have used fractures known as breakouts in oil wells which are controlled by the in situ stress to show that this stress province extends through the western canadian sedimentary basin to the arctic coast there is a strong possibility that a uniform stress orientation with greatest compression ne sw is co extensive with the north american continent east of the rocky mountains excluding the appalachian and gulf of mexico stress provinces we further report new breakout orientations in the far northwest of canada which locate the boundary between the mid continent stress province and an alaskan stress province with largest compression nnw sse probably controlled by the subduction of the pacific plate under alaska

the influence of nonuniform transmissivity and storativity on drawdown although the existence of spatial variability in hydrogeological parameters is widely recognized most analyses of pumping test data are performed under the assumption that the aquifer is adequately characterized by a few parameters for example constant transmissivity constant storativity distance to a barrier and well skin even if the possibility of variability is recognized pumping tests are often thought to investigate the region between a pumping well and an observation well recently however investigations of the sensitivity of pumping test data to radially symmetric nonuniform flow properties have shown that the drawdown at an observation well is insensitive to transmissivity and storativity of the region between the pumping well and the observation well in this paper i use a perturbation approach to derive the frechet derivatives and kernels for the effect of two dimensional areal variations in transmissivity and storativity on drawdown at an observation well frechet derivatives and kernels are related to sensitivity coefficients but their definition is independent of zonation examination of the frechet kernels at large distances from the pumping and observation wells shows that the area of investigation of a pumping test is bounded by an ellipse that encloses both wells this study also shows that observation well drawdown is relatively sensitive to near well transmissivity variation especially if the nonuniformity is not radially symmetric about the well

hypoxia driven variations in iron and manganese shuttling in the baltic sea over the past 8 kyr the baltic sea has experienced three major intervals of bottom water hypoxia following the intrusion of seawater circa 8 kyr ago these intervals occurred during the holocene thermal maximum htm medieval climate anomaly mca and during recent decades here we show that sequestration of both fe and mn in baltic sea sediments generally increases with water depth and we attribute this to shelf to basin transfer shuttling of fe and mn burial of mn in slope and basin sediments was enhanced following the lake brackish marine transition at the beginning of the hypoxic interval during the htm during hypoxic intervals shelf to basin transfer of fe was generally enhanced but that of mn was reduced however intensification of hypoxia within hypoxic intervals led to decreased burial of both mn and fe in deep basin sediments this implies a nonlinearity in shelf fe release upon expanding hypoxia with initial enhanced fe release relative to oxic conditions followed by increased retention in shelf sediments likely in the form of iron sulfide minerals for mn extended hypoxia leads to more limited sequestration as mn carbonate in deep basin sediments presumably because of more rapid reduction of mn oxides formed after inflows and subsequent escape of dissolved mn to the overlying water our fe records suggest that modern baltic sea hypoxia is more widespread than in the past furthermore hypoxia driven variations in shelf to basin transfer of fe may have impacted the dynamics of p and sulfide in the baltic sea thus providing potential feedbacks on the further development of hypoxia