hydrochemical processes in the lower jordan valley and in the dead sea area abstract changes in the concentrations of major some minor and trace elements occurring in both surface and groundwater of the lower jordan river dead sea drainage basin have been investigated in order to identify the characteristics of the regional aquifers and their recharge areas spider patterns of elements and rare earth distribution patterns pinpoint the characteristic chemical features of groundwater as compared to seawater the high br cl ratios in groundwater are caused either by high br cl ratios in precipitation by leaching of br from bituminous matter or by mixing with brines beyond the epsomite stage the locations of groundwater samples with enhanced b contents coincide with the distribution of gypsum in the beds of the lisan formation which produces water with nearly constant b so 4 2 molar ratios aeolian distribution of the unconsolidated lisan sediments influences the b so 4 ratio in the area of lake tiberias and in the jordan highlands the high gd anomaly in the dead sea water is of geologic origin whereas that in the jordan river and in nahal stream qidron is largely anthropogenic the anthropogenic gd input to the dead sea is insignificant compared to the actual amount in the water of the dead sea hot saline water encountered along the western shores of the dead sea with high gd anomalies indicate that they contain large amounts of ancient dead sea water that mix as hot ascending brines with fresh water the recharge area of groundwater in the lower jordan valley extends largely over limestone and dolomite outcrops of the upper cretaceous judea group weathering of locally underlying lower cretaceous volcanics in the area of pezael beqaot and argaman yield groundwater with 34 s so 4 2 values ranging from 2 to 4 the presence of sulphide bearing bodies in this area is attested to magnetic anomalies detected at depths of several kilometres 34 s so 4 2 indicates very deep groundwater circulation high 34 s so 4 2 15 is typical for marine sulphates from the judea and avedat group limestone the springs located along the northwestern shore of the dead sea discharge water replenished on the eastern judea mountains the increase in the salinity of this water is due to brines flushed from sediments and from adjacent sedimentary rocks which host entrapped brines from the precursors of the dead sea formed during the late stages of lake lisan fresher water flushes out these residual brines as a result of falling sea level salinity increase in groundwater is also affected by the ascent of deep seated hot brines from pre sedom periods along the rift faults calculations of mixing between fresh and highly saline end members show that leaching of anhydrite from sediments precipitation of calcite formation of dolomite albitization of plagioclase and ion exchange with abundant clay minerals control the major element composition of the saline groundwater

the origin and mechanisms of salinization of the lower jordan river the chemical and isotopic 87 sr 86 sr 11 b 34 ssulfate 18 owater 15 nnitrate compositions of water from the lower jordan river and its major tributaries between the sea of galilee and the dead sea were determined in order to reveal the origin of the salinity of the jordan river we identified three separate hydrological zones along the flow of the river 1 a northern section 20 km downstream of its source where the base flow composed of diverted saline and wastewaters is modified due to discharge of shallow sulfate rich groundwater characterized by low 87 sr 86 sr 0 7072 34 ssulfate 2 high 11 b 36 15 nnitrate 15 and high 18 owater 2 to 3 values the shallow groundwater is derived from agricultural drainage water mixed with natural saline groundwater and discharges to both the jordan and yarmouk rivers the contribution of the groundwater component in the jordan river flow deduced from mixing relationships of solutes and strontium isotopes varies from 20 to 50 of the total flow 2 a central zone 20 50 km downstream from its source where salt variations are minimal and the rise of 87 sr 86 sr and so4 cl ratios reflects predominance of eastern surface water flows 3 a southern section 50 100 km downstream of its source where the total dissolved solids of the jordan river increase particularly during the spring 70 80 km and summer 80 100 km to values as high as 11 1 g l variations in the chemical and isotopic compositions of river water along the southern section suggest that the zarqa river 87 sr 86 sr0 70865 11 b25 has a negligible affect on the jordan river instead the river quality is influenced primarily by groundwater discharge composed of sulfate rich saline groundwater cl 31 180 mm so4 cl0 2 0 5 br cl2 310 3 87 sr 86 sr0 70805 11 b30 15 nnitrate 17 34 ssulfate4 10 and ca chloride rift valley brines cl 846 1500 mm br cl 6 8 10 3 87 sr 86 sr0 7080 11 b40 34 ssulfate4 10 mixing calculations indicate that the groundwater discharged to the river is composed of varying proportions of brines and sulfate rich saline groundwater solute mass balance calculations point to a 10 contribution of saline groundwater cl282 to 564 mm to the river a high nitrate level up to 2 5 mm in the groundwater suggests that drainage of wastewater derived irrigation water is an important source for the groundwater this irrigation water appears to leach pleistocene sediments of the jordan valley resulting in elevated sulfate contents and altered strontium and boron isotopic compo sitions of the groundwater that in turn impacts the water quality of the lower jordan river copyright 2004 elsevier ltd

origin and mixing history of brines palo duro basin texas u s a formation waters in the palo duro basin texas u s a fall into four major groups based on integrated chemical and isotopic characteristics 1 interbed brines within the major permian evaporite aquitard these are the most chemically concentrated and18o rich fluids in the basin and are interpreted as evaporatively concentrated sea water which has been hydrologically isolated since the permian 2 brines below the salt on the eastern side of the basin have clbr divalent cation and isotopic systematics indicating a mixture of evaporatively concentrated sea water and meteoric water of d 20 3 brines below the salt on the western side of the basin have chemical and isotopic systematics suggesting a mixture of two pulses of meteoric water one with d 20 and the other with d 55 and 4 waters above the salt have the isotopic composition of meteoric waters diagenetic alteration of the cation chemistry has occurred for brines within and below the salt aquifers below the salt on the eastern side are interpreted as having been charged with dense permian evaporite brines which subsequently mixed in various amounts with a basin wide pulse of triassic meteoric water on the western side the descending triassic meteoric waters became saline by dissolution of halite and are currently mixing with a tertiary pulse of meteoric water initiated by the laramide uplift to the west the hydrochemistry suggests flow on the western side of the basin and static conditions on the eastern side an unrecognized approximately n s permeability restriction or discontinuity in the potentiometric flow surface is inferred for major aquifers in the central area of the basin

groundwater chemistry and water rock interactions at stripa groundwaters from near surface to a depth of 1232 m in the stripa granite have been sampled and analyzed for major and trace constituents the groundwater composition consists of two general types a typical recharge water of ca hco3 type 700 m depth of high ph 8 10 that reaches a maximum of 1250 mg l in total dissolved solids tds intermediate depths show mixtures of the two types that are highly fracture dependent rather than depth dependent any borehole can vary significantly and erratically in tds for either a horizontal or vertical direction the general transition from ca hco3 type to na ca cl type correlates with the depth profile for hydraulic conductivity that drops from 10 8 m s to 10 11 m s or lower thermomechanical stress from heater experiments clearly shows an effect on the groundwater composition that could be caused by changing flow paths leakage of fluid inclusions or both dissolution and precipitation of calcite fluorite and barite aluminosilicate hydrolysis and addition of a saline source possibly fluid inclusion leakage play the major roles in defining the groundwater composition the low permeability of the stripa granite has produced a groundwater composition that appears intermediate between the dilute shallow groundwaters typical of recharge in a crystalline rock terrain and the saline waters and brines typical of cratonic shield areas at depth

chemistry and isotopic composition of rotliegend and upper carboniferous formation waters from the north german basin abstract element concentrations and isotopic composition d 18 o 15 n of ammonium 87 sr 86 sr have been determined in highly saline formation waters from the rotliegend altmark gasfield and the upper carboniferous husum schneeren gasfield in the north german basin both reservoirs have been covered by huge zechstein evaporite caps since the late permian formation waters from the altmark gasfield are characterized by high total dissolved solids and are enriched in 18 o relative to meteoric waters and either show positive or negative d values which typically follow the proposed d vs 18 o paths for seawater evaporation formation waters stored in upper carboniferous sandstones show much more variable element concentrations and 18 o and d values than the rotliegend formation waters the br vs cl concentrations of the brines suggest seawater evaporation being the principal source of salinity at both sites the ammonium concentrations in the analyzed brines are highly variable and the 15 n isotopic composition of dissolved ammonium is controlled either by the isotopic composition of the gas in the reservoir rotliegend or that of the host rocks upper carboniferous at both sites early formation waters interacted with the sedimentary host rocks after deposition 87 sr 86 sr ratios suggest that re equilibration between fluids and their host rocks occurred in pre triassic times there is no chemical or isotopic evidence that original formation waters which occur in sandstone below the overlying zechstein evaporites were flushed out or mixed by later meteoric water as has been documented in deep seated mesozoic and other paleozoic aquifers of the north german basin

evolution of the northeast german basin inferences from a 3d structural model and subsidence analysis abstract a 3d structural model of the northeast german basin was evaluated with special emphasis on its evolution as an intracontinental depression the study includes investigations on subsidence history and structural setting of the basin thickness evolution and calculated tectonic subsidence volumes of permian to quaternary sediments in the northeast german basin indicate that the subsidence history was related to five stages of basin evolution which differ in their subsidence mechanisms for the initial rift phase in the late carboniferous to early permian a dominant thermal event and subordinate horizontal stresses were indicated by thickness variation evolution and by structural evidence the main part of basin subsidence occurred in a nw se oriented basin in the subsequent phase of thermal relaxation with maximum subsidence from early permian rotliegend to middle triassic muschelkalk from middle triassic the thermal subsidence pattern was superposed by further tectonic events in the middle triassic regional extension led to a reconfiguration of the southern part of the basin where new nne ssw trending troughs rheinsberg and gifhorn troughs developed in the jurassic the northwestern part of the basin was uplifted while in the south the keuper subsiding areas continued to sink and nw se trending depressions related to salt margins became important differentiation continued into cretaceous times when regional compression caused uplift of the southeastern part of the basin and basin margins a final subsidence phase occurred in the cenozoic this was accompanied by intensive salt movement recent basin configuration reflects the superposition of structural elements resulting from different evolution stages the main structural characteristics of the basin are 1 a vertical tectonic zonation in a pre zechstein succession which lacks significant internal structures and a strongly deformed post zechstein succession which was decoupled due to the thick zechstein salt and 2 a marked asymmetry of the basin with a shallow northern slope and a steep bounding fault at the southern margin elbe fault system the northwestern part of the basin shows the structural properties of an intracratonic sag basin with persisting subsidence and with minor salt mobilisation in contrast initial structures in the southeastern part are strongly overprinted by younger tectonic events including middle triassic to jurassic extension late cretaceous inversion and late to post cretaceous salt movements tectonic elements that deform the whole sedimentary succession are restricted to the basin s southern eastern and northeastern margins where salt thickness decreases combined volumetric and backstripping investigations show that 2 3 of the total subsidence was induced by the sediment load and 1 3 was caused by tectonics the tectonic subsidence history varies laterally across the basin while tectonic subsidence curves in the northwestern part of the basin show fast subsidence during the permian and early triassic decreasing exponentially with time subsidence curves in the southeastern part indicate repeated tectonic activity however the tectonic subsidence volume created during permian to late triassic is significantly higher than the tectonic subsidence during younger phases of basin history

the saline waters of llandrindod and builth central wales saline or brackish mineral waters have been recorded at several locations in mid wales and the welsh borderlands the main groups are centered on llandrindod wells and builth wells where maximum salinities of 5340 and 16 380 mg l 1 respectively are found the total discharge from these springs is very low combined 2 l s 1 yet their flow remains almost constant residence times of several thousand years are derived using 14 c analysis and 18 o and 2 h results suggest that the waters at llandrindod although not at builth contain a component of late pleistocene water evidence from the br cl ratios and trace elements indicates that the origin of the salinity lies within the lower palaeozoic formations and has not been derived from evaporites the mineral waters have undergone complete reduction of sulphate which has led to high concentrations of ba maximum 53 2 mg l 1 at llangammarch wells the most likely origin of these waters is the deep circulation of meteoric water over a residence time of several thousand years which has risen slowly along minor fracture systems to the points of outlet the interconnected fracture storage of these waters implied from the various lines of evidence must be of the order 30 mm 3

groundwater in the celtic regions this book covers a diverse range of hydrogeological environments that occur in the celtic regions of britain and ireland these include hard rock aquifers of lower palaeozoic and precambrian age generally dominated by fracture flow within a shallow zone of weathering carboniferous limestone aquifers often characterized by conduit flows in karstic systems dual porosity permo triassic sandstone aquifers and quaternary deposits many of which form shallow granular aquifers the papers presented here address a number of current issues common to the celtic regions including groundwater protection policies groundwater management in karst aquifers groundwater development in quaternary aquifers groundwater evaluation in data scarce aquifers and groundwater supplies to small island communities

weathering rinds and rock coatings from an arctic alpine environment northern scandinavia coarse rock debris exposed in the subaerial environment of northern sweden displays the development of a wide variety of surface coatings these include weathering rinds as well as a great diversity of geochemical coatings including those dominated by ca fe si and al each of these types of rock coatings displays a high degree of geochemical complexity the weathering rinds exhibit both geochemical and morphologic changes to the parent rock cores including extensive dissolution oxidation and hydration as well as disaggregation fracturing and cementation by secondary geochemical coatings chemical breakdown of the rock to form weathering rinds includes loss of k si mg and ca and buildup of fe weathering rinds are fundamentally the result of dissolution as no clay minerals were identified in the rinds rock coatings are distinguished from rinds by their clear accretionary nature despite the distinction made between weathering rinds and rock coatings it is important to note that often the two are intimately related the presence of rock coatings as well as weathering rinds on rock surfaces amplifies the important role played by geochemical processes in the arctic alpine climate of northern sweden in particular as well as its significance in landscape evolution in such environments in general

origin distribution and movement of brine in the permian basin u s a a model for displacement of connate brine na cl halite ca cl and gypsum ca cl brines with salinities from 45 to 300 g l are identified and mapped in four hydrostratigraphic units in the permian basin area beneath western texas and oklahoma and eastern new mexico providing spatial and lithologic constraints on the interpretation of the origin and movement of brine na cl brine is derived from meteoric water as young as 5 10 ma that dissolved anhydrite and halite whereas ca cl brine is interpreted to be ancient modified connate permian brine that now is mixing with and being displaced by the na cl brine displacement fronts appear as broad mixing zones with no significant salinity gradients evolution of ca cl brine composition from ideal evaporated sea water is attributed to dolomitization and syndepositional recycling of halite and bittern salts by intermittent influx of fresh water and sea water halite ca cl brine in the evaporite section in the northern part of the basin differs from gypsum ca cl brine in the south central part in salinity and na cl ratio and reflects segregation between halite and gypsum precipitating lagoons during the permian ca cl brine moved downward through the evaporite section into the underlying lower permian and pennsylvanian marine section that is now the deep basin brine aquifer mixing there withmore pre existing sea water buoyancy driven convection of brine dominated local flow for most of basin history with regional advection governed by topographically related forces dominant only for the past 5 to 10 ma 71 refs 11 figs less

the displacement of connate water from aquifers a mathematical model is developed for the mixing of meteoric and original formation waters in homogeneous aquifers the theoretical analysis indicates that geologic formations that have had a few to a few tens of pore volumes of meteoric water pass through them may be at steady state with respect to further displacement of their contained fluids depending on constraints in the recharge area the steady state may vary from near meteoric water throughout the whole formation to a spatial variation in concentration ranging from meteoric water in the recharge areas to highly concentrated water at the discharge ends of the system the former condition is attained when the recharge area incorporates the total depth and breadth of the formation where this condition is not satisfied the concentrations that evolve are controlled by the original concentration of the formation water the composition of recharging meteoric water the dispersion parameters and the size of the recharge area in comparison to the total breadth of the formation as measured along its strike for heterogeneous formations the concentration patterns that evolve seem to depend further on contrasts in hydraulic conductivity this is demonstrated in the milk river sandstone which is characterized by several extensive zones of dilute water within narrow high conductivity pathways and marked increases in concentration in adjacent lower permeability rock in parts of the aquifer where higher permeability pathways appear to be absent the isochlores form a broad linear band with a marked increase in concentration in the flow direction

rare earths and yttrium hydrostratigraphy along the lake kinneret dead sea arava transform fault israel and adjoining territories rare earth elements and y rey have been analysed in 49 groundwaters from localities in the areas of lake kinneret and the jordan and arava valleys these waters originate from various aquifers and the rey abundances are expected to be controlled by the aquifer rocks the rey pattern allow one to distinguish interaction of waters with basalts basalt limestone interaction zones silicified limestones limestones from the judea and avdat groups upper cretaceous and eocene respectively and sandstones of the lower cretaceous kurnub group groundwater from the quaternary alluvial fill dead sea group are either controlled by judea group limestone or kurnub group sandstone the rey patterns show characteristic features for each group in hydrogeological systems the rocks of natural replenishment areas are usually not the same as rock units from which the waters are collected this becomes evident by comparing the lithostratigraphic groups from which the waters were collected and the hydrochemical grouping according to rey patterns with their characteristic trends and anomalies in many cases there is a correspondence between the lithostratigraphic and the hydrochemical grouping in other cases the 2 groupings disagree this disagreement proves inter aquifer flow of groundwater in some cases the geologically derived aquifers rocks of origin differ from those indicated by rey patterns thus applying the rey grouping new fundamental information for hydrological models can be given and sources of salinisation can be elucidated

implications of trace element composition of syntaxial quartz cements for the geochemical conditions during quartz precipitation in sandstones a petrographic investigation revealed polyphase quartz cementation in the finefrau sandstone upper carboniferous western germany and the solling sandstone lower triassic central germany three different cements could be distinguished in each sandstone based on their cathodoluminescence and trace element composition the first quartz generation is suggested to have been formed during eogenesis due to dissolution and replacement of feldspar the mesogenetic paragenesis comprises two generations of quartz and illite which are accompanied by albite in the solling sandstone sharp luminescence zoning in quartz overgrowths points to distinct episodes of cementation in both sandstones significant amounts of al li and h and traces of ge and b have been detected in the quartz overgrowths the al content of the quartz cements in the finefrau sandstones exceeds that in the quartz cements in the solling sandstone by a factor of five it is suggested that this compositional variation reflects the conditions in the pore water such as temperature and ph the al concentration is generally correlated to the li content with the exception of the latest quartz generation in the finefrau sandstones which is also most enriched in trace elements the ratio of li al varies between 0 11 and 0 25 in the two sandstones the li h ratio which ranges from 0 12 to 0 3 is controlled by the activity ratio of li and h in the pore fluid clay minerals are the most important source for li and high salinities favour the mobilization of li during diagenesis thus a relatively low salinity and low ph are responsible for the low li h ratio in the finefrau sandstone while high salinity and neutral to alkaline ph results in a high li h ratio for the solling sandstone the ge contents are generally near the average of detrital quartz and indicate that pressure dissolution is a major source for quartz cementation different chemical compositions of distinct quartz generations indicate changes in the physico chemical conditions and point to mobilization of silica from different sources for example pressure solution and clay mineral transformations

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

role of the bacterium thiobacillus in the formation of silicates in acidic mine tailings acidophilic chemolithotrophic bacteria such as thiobacillus are commonly found in sulfidic mine tailings they oxidize fe ii and reduced sulfur species from sulfide minerals left in tailings and produce acidic leachates loaded with heavy metals our study of the kam kotia mine tailings cu zn ore an abandoned mine located near timmins ontario canada showed that thiobacillus played an important role in the in situ formation of silicates transmission electron microscopic observations of ultrathin sections of tailings revealed the presence of bacteria with fine grained silica sio2 associated with their cell walls under laboratory conditions mimicking the chemistry of the pore waters of the tailings i e identical ph fe si and so4 thiobacillus promoted the rapid formation 48 h of amorphous silica at low ph values ph 2 2 2 3 while an abiotic system with the same chemical conditions did not show silica precipitation however in the presence of fe oxides silica formation was not observed because dissolved si was preferentially sorbed to the surface of the oxides in addition when the cells were grown in the presence of micas biotite and muscovite under acidic conditions mixed mg al si fe silicate precipitates were formed on the surface of thiobacillus these results indicate that si cycling and solubility in mine tailings could be strongly influenced by bacteria especially in sulfide depleted tailings like the kam kotia ones where the formation of fe oxide is negligible

a diffusive ion flux of non marine origin in cumbrian lake sediments implications for element budgets in catchments abstract diffusion controlled concentration gradients of many elements exist in the sediments of derwentwater lake cumbria northern england which indicate hydraulic connection with a reservoir of high salinity water a widely distributed source of saline groundwater beneath cumbria with a composition that is compatible with anomalous surface water chemistry is demonstrated element and stable isotope characteristics indicate that the most likely source of enhanced salinity is from water rock interaction at depth involving the lake district granite batholith and surrounding meta sediments these results demonstrate the permeability and reactivity of basement rocks and suggest also that chloride cannot be regarded as conservative in water balance studies

the role of seawater freezing in the formation of subsurface brines abstract several mechanisms evaporation water rock interaction ultra filtration have been suggested to explain the evolution of ubiquitous ca chloride subsurface brines in the present paper the freezing of seawater in polar regions and in even wider areas during glacial periods is proposed as an additional possible path of brine formation four detailed seawater freezing experiments to 14 c resulting in a concentration factor of about 5 were carried out and na k ca mg sr cl so4 and br were analysed in the residual brines and in the ice br and sr whose behavior during the freezing of seawater is reported here for the first time show a conservative behavior throughout the studied temperature range our data and earlier literature show that the high salinities which are common in subsurface brines 300 g l may be obtained by the removal of h2o as ice in the primary glacial environment the decrease in the na cl ratio is caused by the crystallization of mirabilite na2so4 10h2o supplemented by hydrohalite nacl 2h2o sulfate is removed both in mirabilite and by bacterial reduction the brine then migrates to the subsurface heats up under the local geothermal gradient and interacts with the adjacent rocks at this stage it may be diluted by meteoric waters its mg ca ratio decreases dolomitization and chloritization the so 4 cl ratio varies according to the local gypsum anhydrite equilibrium conditions and the ca so 4 hco 3 ratio increases as a result of dolomitization or chloritization the interaction with rocks in the subsurface may affect both the original 87 sr 86 sr and the 18 o 16 o ratios of the brine although several of the processes which lead to the formation of ca chloride brines are common for both the evaporative and the freezing models the na br cl relationship in a given brine can be used to discriminate between the two modes of brine evolution several subsurface brines from the canadian shield and one brine from finland are used as examples of the seawater freezing model and an explanation is proposed for the necessary mass production of brines in glacial environments

isotopic evidence for palaeowaters in the british isles before the 20th century groundwater circulation in the aquifers of the british isles had largely adjusted to the temperate maritime climate and sea levels established over the past 10 ka since the end of the pleistocene however in the last 100 a this natural regime has been disturbed by abstraction of water for public supply and industrial use and palaeowaters from earlier recharge episodes are now becoming a factor to be considered in water balance estimates this paper presents a synthesis of the existing palaeowater distribution in the british isles based on isotopic evidence 18o 2h and and14c as such it has relevance to palaeoclimatic studies in addition to the water resource implications the triassic basins of england and northern ireland contain saline waters beyond the range14c dating 40 ka stable isotopic ratios show enrichment in some basins and depletion in others without an overall pattern that would explain all the observed compositions the results for the wessex basin suggest recharge in pre quaternary times but for the other basins some flushing by pleistocene or holocene meteoric waters is indicated isolated occurrences of apparently long residence waters are found elsewhere throughout the british isles for example from carboniferous and lower palaeozoic strata in such cases environmental isotopes are more useful as constraints on hydrogeological models than as indicators of palaeoconditions major water supply aquifers are restricted almost entirely to england the two sandstone formations triassic sherwood sandstone and cretaceous lower greensand have a greater range of stable isotopic values between phreatic and confined conditions than the two carbonate formations jurassic lincolnshire limestone and cretaceous chalk this indicates that the sandstone aquifers are better archives of information on palaeoconditions than the carbonate aquifers they show that atmospheric circulation patterns over britain have probably remained the same since the late pleistocene however 14c data from all four of the major aquifers emphasise the hiatus in recharge during periglacial conditions which occurred between the late pleistocene and early holocene

groundwater medicine by the glassful knowledge of the healing properties of some groundwater sources has been passed down through the generations a complex array of hydrogeological environments yields a rich and diverse range of chemical compositions and cures for a variety of ailments were available from some spring waters many were sourced with associated religious overtones it is likely that exposure to clean cold water alleviates the symptoms of leprosy and probable also that it relieves rheumatic pain however the only demonstrable medicinal properties of groundwater are its purging effects wherever mgso4 or epsom salts prevailed clean and potable groundwater is certainly a key to human health and some of the minerals dissolved within it are essential to the human body although many of these minerals become toxic if present in excess the modern fashion for bottled groundwater often perceived to be associated with health giving and medicinal properties for the most part merely offer a safe form of drinking water the curative and medicinal properties of groundwater have been recognized correctly or otherwise for several thousands of years the founding of the english city of bath with its well known spa waters goes back to 863 bc when the young prince bladud contracted leprosy and was banished from his father s royal court bowman 1998 he was set to work as a swine herdsman but soon his pigs also caught the disease but one day when the pigs had been wallowing in a warm mud spring by the river one by one they emerged from the mud with clear signs of healing on seeing this bladud did likewise and he too emerged cleansed with greatly improved health the prince was able to return to his royal duties later becoming the mythical god king father to king lear but more importantly making the link between groundwater and medicine many years later robert the bruce would enjoy the same cure this time at a spring emerging from devonian sandstone at scotlandwell in fife robins et al 2004 this was a story that was repeated throughout europe and the americas for hundreds of years the story of bath encapsulates the belief that groundwater is a healing agent several centuries after prince bladud s experience the romans came upon the springs at bath and with their usual enthusiasm for hot springs developed the site into the famous roman baths that survive today the baths prospered for four centuries before they fell into disrepair with the collapse of the roman empire interest was renewed from the late seventeenth century when bath became a fashionable resort that

a silicate weathering mechanism linking increases in marine 87sr 86sr with global glaciation the 87sr 86sr ratio of sea water is generally regarded as a proxy for the rate of chemical weathering of the continents interpretation of the 87sr 86sr record in marine limestones requires an understanding of how changes in this quantity are linked to climate and tectonic events a connection between the strontium isotope record and the extent of global glaciation has been proposed1 8 but without a well established mechanism glaciation may influence marine 87sr 86sr by changing global riverine sr fluxes that is rock weathering rates and or 87sr 86sr ratios that is relative mineral weathering rates here we investigate how the 87sr 86sr release from silicate weathering is affected by glaciation using the sr isotope systematics of granitoid soils on alpine glacial moraines in the wind river range wyoming we observe a negative correlation between the 87sr 86sr ratio of exchangeable sr in soils and the soil age indicating that the 87sr 86sr ratio of sr released in the early stages of weathering is significantly higher than in later stages we estimate that this mechanism can increase global riverine 87sr 86sr by an average of 0 0002 during periods of glacial interglacial cycling when superimposed on long term trends controlled by tectonic processes2 7 9 10 this shift can account for the correlation between the rate of change of marine 87sr 86sr and the intensity of glaciation over at least the past 10 myr

s and o isotopic character of dissolved sulphate in the cover rock aquifers of a zechstein salt dome abstract sulfur and o isotope analyses of dissolved so4 were used to constrain a hydrogeological model for the area overlying the gorleben rambow salt structure northern germany samples were collected from 80 wells screened at different depth intervals the study area consists of a set of two vertically stacked aquifer systems generally the isotope data show a good spatial correlation outlining well defined groundwater zones containing so4 of characteristic isotopic composition highly saline waters from deeper parts of the lower aquifer system are characterized by rather constant so4 isotopic compositions which are typical of permian zechstein evaporites 34s 9 6 11 9 18o 9 5 12 1 above this is a transition zone containing ground waters of intermediate salinity and slightly higher isotopic values average 34s 16 6 18o 15 3 the confined groundwater horizon on the top of the lower aquifer system below the low permeable hamburg clays is low in total dissolved solids and is characterized by an extreme 34s enrichment average 34s 39 1 18o 18 4 suggesting that bacterially mediated so4 reduction is a dominant geochemical process in this zone two areas of distinct isotopic composition can be identified in the shallow ground water horizons of the upper hydrogeological system sulfate in groundwaters adjacent to the river elbe and locknitz has a typical meteoric isotopic signature 34s 5 2 18o 8 2 whereas the central part of the area is characterized by more elevated isotopic ratios 34s 12 7 18o 15 6 the two major so4 pools in the area are represented by permian seawater so4 and a so4 of meteoric origin that has been mixed with so4 resulting from the oxidation of pyrite it is suggested that the s isotope compositions observed reflect the nature of the so4 source that have been modified to various extent by bacterial so4 reduction groundwaters with transitional salinity have resulted from mixing between brines and low mineralized waters affected by bacterial so4 reduction

formation of rotliegend ca cl brines in the north german basin compared to analogues in the geological record abstract the formation of terrestrial ca cl brines is controlled by two major processes chemical reactions between halite brines and igneous and metamorphic rocks and or their debris in sedimentary basins and the abstraction of h 2 o by evaporation freezing or formation of hydrous minerals albitization dominates in environments of low h 2 o activity i e halite saturated systems chloritization serpentinization and formation of smectites seems to be related to less saline systems i e enhanced water activity the rotliegend brines of the north german basin evolved by interaction of infiltrating halite brines with volcanic debris of the permian acid volcanic rocks by albitization and chloritization of plagioclase at present their temperatures are between 130 and 150 c at 3000 4000 m depth although they developed in a different environment they chemically and isotopically resemble the basinal brines from the mississippi salt dome basin or even the deep brines from the red sea all these brines have in common that halite brines interacted with plagioclase an sio 2 2na 2alb ca 2 or possibly with clay minerals ca clay 2na na 2 clay ca 2 at enhanced temperatures the trends of stable isotopes show slopes in the d 18 o diagram which are typical for hydrothermal reactions of evaporation brines with rock or sediments the genesis of rotliegend brines differ from ca cl brines in the canadian shield siberian platform the dry valleys in antarctica and even the local brines from the chilean salars and the californian bristol dry lake the antarctic dry valley brines seem to be dominated by melting of ice cements of their permafrost sections the ca cl brines of springs in the chilean salars and the bristol dry lake ascend due to thermal convection along tectonic faults although the canadian shield brines chemically resemble those of the siberian platform their stable isotope fractionation suggest that they developed by different processes of water abstraction exotic stable isotope values in brines are gained by freezing or ultrafiltration processes in the precursor sediments of the present crystalline rocks of the canadian shield and by small volume ratios of liquids and metamorphic rocks such as of ktb vb

iron containing weathering products of basalt in a cold dry climate two different microenvironments for secondary iron mineral formation in a basaltic stone exposed to weathering in the cold dry climate at the top of a nunatak in greenland have been investigated at the upper exposed surface a red stained rind varnish has formed and within a crack a loose reddish brown material and a greenish coloured material were found the weathering products were identified by 57fe mossbauer spectroscopy x ray diffraction and infrared spectroscopy the reddish stain on the exposed surface consists of hematite in contrast the reddish brown material from the crack contains goethite and magnetite maghemite but no hematite could be detected nontronite is the main mineral in the greenish material the conditions determining the neoformation of minerals in the two environments are briefly discussed

the pontesford lineament welsh borderland the ne trending pontesford lineament centres on the pontesford linley and adjacent faults in the shelve longmynd inlier to the ne it is usually drawn along the se edge of the cheshire basin and to the sw along a variety of lines parallel to or converging with the church stretton fault new mapping and reassessment of published data suggest that sw of the pontesford linley fault the lineament is logically drawn along the clun forest disturbance a post pridoli late silurian fold fault belt then across the nw side of the llandrindod inlier to flank the tywi lineament the lineament was intermittently active at least from mid ordovician through to triassic time with both strike slip and dip slip displacements that involved the upper part of the precambrian basement late ordovician and early silurian strike slip was particularly important the lineament controlled the sites of several silurian sedimentary basins ordovician contrasts across the lineament can be explained either by contemporary fault control or by subsequent large displacements juxtaposing unlike terranes the long history of reactivation and basement control on the pontesford lineament is typical of lineaments throughout wales and the borderland it suggests that both caledonian and variscan structural trends n of the variscan front may be inherited from older pre silurian or even precambrian basement structures

controls on the regional scale salinization of the ogallala aquifer southern high plains texas usa an extensive saline plume 250 km 2 within the regionally important unconfined aquifer in the neogene ogallala formation overlies the panhandle oil and gas field in the southern high plains texas usa relative to upgradient ogallala water the plume waters have d 18 o 6 7 to 8 8 and d d 42 to 88 values that tend to be depleted and have higher cl 150 mg l and so4 75 mg l concentrations various end member mixing models suggest that the plume composition reflects the presence of paleowaters recharged during middle to late wisconsinan time rather than salinization associated with petroleum production paleowaters probably mixed with salt dissolution zone waters from the underlying upper permian formations before discharging upward into the ogallala formation cross formational discharge is controlled primarily by the geometry of the underlying units as influenced by the amarillo uplift pinch out of the laterally adjoining confined aquifer in the triassic dockum group variations in the saturated thickness of the ogallala aquifer and the presence of potential pathways related to salt dissolution 2000 elsevier science ltd all rights reserved

thermomineral waters of ca chloride composition review of diagnostics and of brine evolution ca chloride waters are defined as those in which q rca r so4 hco3 1 rna rcl 0 80 rmg rca 0 5 and wcl wbr 286 r meq l 1 and w mg l 1 throughout the last 50 years different models for the formation of such waters have been suggested these models include 1 filtration through semipermeable membranes under conditions of highly compacted argillaceous sediments 2 deaquation of seawater by evaporation and or by freezing followed by dolomitization 3 hydrolysis of plagioclase and biotites in igneous metamorphic rock masses 4 radiolytic modification of residual metamorphic fluids and 5 dissolution of chalks followed by ion exchange on smectites the better understanding of processes and of natural environments leading to the evolution and natural occurrence of such brines is imperative for the prospection and further sustained exploitation of such waters

naturally occurring radionuclides and their geochemical interactions at a geothermal site in the north german basin the activities of the most common naturally occurring radionuclides 238u 226ra 210pb 228ra 228th and 40k were measured by gamma ray spectrometry in samples from reservoir rocks geothermal fluids and mineral precipitates at the geothermal research site gros schonebeck north german basin results demonstrated that the specific activity of the reservoir rock is within the range of the mean concentration in the upper earth crust of 800 bq kg for 40k and 60 bq kg for radionuclides of the 238u and 232th series respectively the geothermal fluid showed elevated activity concentrations up to 100 bq l for 226ra 210pb and 228ra as compared to concentrations found in natural groundwater their concentration in filter residues even increased up to 100 bq g these residues contain predominantly two different mineral phases a sr rich barite sr baso4 and laurionite pbohcl which both precipitate upon cooling from the geothermal fluid thereby they presumably enrich the radionuclides of ra by substitution of ba and pb analysis of these precipitates further showed an increased 226ra 228ra ratio from around 1 1 7 during the initial months of fluid production indicating a change in fluid composition over time which can be explained by different contributions of stimulated reservoir rock areas to the overall produced fluid

cyclostratigraphy of the reference section for the cretaceous white chalk of northern germany lagerdorf kronsmoor a late campanian early maastrichtian orbital time scale new carbonate records of the upper campanian lower maastrichtian white chalk of northern germany at lagerdorf kronsmoor represent a continuous succession suitable for time series analysis the boreal chalk succession is characterized by several intervals of reduced carbonate content in the basiplana spiniger polyplocum upper langei and upper grimmensis granulosus to pseudoobtusa boreal macrofossil zones which are mainly related to periods of increased detrital supply results of spectral analysis on the carbonate time series allow the detection of the periodicities of long and short eccentricity the long eccentricity signal can be extended to the entire upper campanian comprising a total of 15 25 long eccentricity cycles a minimum time span of 6 2 ma and an age of 77 5 0 4 ma for the lower upper campanian boundary the long eccentricity cycles detected from chalk carbonate contents correlate with long eccentricity cycles detected in self potential logs of boreholes proving their significance within different depositional settings and rates of subsidence in the north german basin the biostratigraphic consistent occurrence of long eccentricity cycles provides evidence for the completeness of the sedimentary record the long term intervals of increased detrital supply are the expression of increased progradation of clay minerals related to a long term sea level fall with superimposed short sea level falls within a 2 5 million year interval spanning the campanian maastrichtian boundary it cannot be decided from the present state of knowledge if this signal is controlled by increased erosion due to uplift of inverted structures by eustatic sea level fall or a combination of both the detection of the long eccentricity suggests an orbital forcing superimposed on a long term regressive trend

fluid rock interactions in a geothermal rotliegend permo carboniferous reservoir north german basin abstract comprehensive data on the chemical composition of reservoir rocks and geothermal brines from the geothermal well doublet gro schonebeck north german basin drilled into a rotliegend sedimentary and permo carboniferous volcanic rock reservoir were sampled over the past years they were characterized with respect to their major and minor elemental composition including various isotope ratios the study considered the impact of drilling and reservoir operations on fluid composition and aimed at determining fluid rock interactions to gain information on fluid origin and hydraulic pathways the highly saline fluids up to 265 g l tds show 18 o and d of water 2 7 5 6 and 3 1 15 respectively as well as 34 s of sulfate 3 6 5 and 87 sr 86 sr ratios 0 715 0 716 that resemble rotliegend brines from an area located around 200 km in the west the altmark halogen ratios indicated that brines developed predominantly by evaporation of meteoric water primary brine together with halite dissolution brine secondary brine indication for mixing with zechstein brine or with younger meteoric water was not found no geochemical distinction was possible between fluids deriving from different rock formations dacites or sedimentary rocks respectively this is due to the evolution of the sediments from the effusive rocks resulting in a similar mineralogical and chemical composition and due to a hydraulic connectivity between the two types of rock this connection existed probably already before reservoir stimulation as indicated by a set of faults identified in the area that could connect the rotliegend formation with both the volcanic rocks and the lower units of the zechstein additional geochemical indication for a hydraulic connectivity is given by 1 the very high heavy metal contents mainly cu and pb in fluids and scaling that derive from the volcanic rocks and were that were also found in increased amounts up at the zechstein border kupferschiefer formation 2 the 87 sr 86 sr isotope ratios of fluid samples correspond to the ratios determined for the sedimentary rocks indicating that initially the fluids developed in the sedimentary rocks and circulated later when faults structures were created by tectonic events into the volcanic rocks

fluid dynamics driving saline water in the north east german basin in several areas of the north german basin saline water comes close to or even reaches the surface available data from wells indicate that brine stratification is under unstable conditions in the deeper underground in order to analyse the possible transport mechanisms 3d thermohaline simulations have been carried out for two different scenarios the 3d regional model 230 330 km indicates that salty water is driven to the surface by hydrostatical forces from the surrounding highlands in addition a smaller scale model 10 10 km has been constructed with a grid resolution accounting for possible convective flow the results indicate that convective flow may play a dominant role in areas with minor topography in summary the complex pattern of near surface occurrences of saline water probably results from the interaction of hydrostatic and thermal forces

quaternary channels within the northeast german basin and their relevance on double diffusive convective transport processes constraints from 3 d thermohaline numerical simulations 1 the internal geological structure of the northeast german basin negb is affected by intense salt diapirism and by the presence of several stratified aquifer complexes of regional relevance the shallow quaternary to late tertiary freshwater aquifer is separated from the underlying mesozoic saline aquifers by an embedded tertiary clay enriched aquitard rupelian aquitard an important feature of this aquitard is that hydraulic connections between the upper and lower aquifers do exist in areas where the rupelian aquitard is missing hydrogeological windows three dimensional thermohaline numerical simulations are carried out to investigate the effects of such hydrogeological windows in the rupelian aquitard on the resulting groundwater temperature and salinity distributions numerical results suggest that hydrogeological windows act as preferential domains of hydraulic interconnectivity between the different aquifers at depth and enable vigorous heat and mass transport which causes a mixing of warm and saline groundwater with cold and less saline groundwater within both aquifers in areas where the rupelian aquitard confines the mesozoic aquifer dissolved solutes from major salt structures are transported laterally giving rise to plumes of variable salinity content ranging from few hundreds of meters to several tens of kilometers furthermore destabilizing thermal buoyancy forces may overwhelm counteracting stabilizing salinity induced forces offside of salt domes this may result in buoyant upward groundwater flow transporting heat and mass to shallower levels within the same mesozoic aquifer

salinization of groundwater in the north german basin results from conjoint investigation of major trace element and multi isotope distribution conjoint consideration of distribution of major rare earth elements ree and y combined to rey and of h o c s sr isotopes reveals that four types of groundwater are distinguishable by their chemical composition presented by spider patterns rey patterns indicate thermo saline deep water and two types of shallow saline groundwaters presence of connate waters is not detectable sr isotope ratios distinguish three sources of sr fast and slow weathering of biotite and k feldspar in pleistocene sediments respectively and dissolution of limestones 13c dic indicate dissolution of limestone under closed and open system conditions numerous samples show 13c dic 13 which is probably caused by incongruent dissolution of calcite and dolomite the brines from below 1 000 m represent mixtures of pre pleistocene seawater or its evaporation brines and infiltrated post pleistocene precipitation the shallow waters represent mixtures of pleistocene and recent precipitation salinized by dissolution of evaporites or by mixing with ascending brines the distribution of water types is independent on geologic units and lithologies even the tertiary rupelian aquiclude does not prevent salinization of the upper aquifer

investigating the interaction between crescent spring and groundwater in a chinese dune lake environment using hydraulic gradient and isotope analysis methods this paper investigates the interaction between groundwater and groundwater dominated crescent spring in an aeolian sand environment to determine the drainage source of groundwater for the lake using hydraulic gradient and isotope analysis methods the precipitation is found to have an insignificant effect on the lake in an arid climate environment hydrogen and oxygen isotopic evidence presents at least two aquifer contributions that recharge 87 and 13 water supply of the lake respectively the flow direction of groundwater is theoretically established based on the hydraulic gradient and isotope analysis methods

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

book reviewgeothermal energy the potential in the united kingdom r a downing and d a gray editors h m s o norwich 1986 xiii 187 pp stg 20 00 paperback