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Strontium isotope geochemistry of groundwater in the central part of the Dakota (Great Plains) aquifer, USA
Abstract
The Dakota aquifer of the central and eastern Great Plains of the United States is an important source of water for municipal supplies, irrigation and industrial use. Although the regional flow system can be characterized generally as east to northeasterly from the Rocky Mountains towards the Missouri River, locally the flow systems are hydrologically complex. This study uses Sr isotopic data from groundwater and leached aquifer samples to document the complex subsystems within the Dakota aquifer in Nebraska and Kansas. The interaction of groundwater with the geologic material through which it flows has created spatial patterns in the isotopic measurements that are related to: long-term water–rock interaction, during which varying degrees of isotopic equilibrium between water and rock has been achieved; and the alteration of NaCl fluids by water-rock interaction. Specifically, Sr isotopic data distinguish brines from Kansas and western Nebraska from those in eastern Nebraska: the former are interpreted to reflect interaction with Permian rocks, whereas the latter record interaction with Pennsylvanian rocks. The Sr isotopic composition of groundwater from other parts of Nebraska and Kansas are a function of the dynamic interaction between groundwater and unlithified sediments (e.g., glacial till and loess), followed by interaction with oxidized and unoxidized sediments within the Dakota Formation. This study illustrates the power of combining Sr chemistry with more conventional geochemical data to obtain a more complete understanding of groundwater flow systems within regional aquifer systems where extensive monitoring networks do not exist.
... Cumulate 3 H yields in the reactors at FDNPP have been estimated to range from 0.01% to 0.0108% 6,7 . According to estimates made immediately after the accident in 2011, there were reports that the inventory of 3 H at the time of the accident was 1.81 × 10 13 Bq 8 , but according to recent reports by Tokyo Electric Power Company Holdings (TEPCO), the inventory of 3 H immediately after the accident was estimated to be 1.0 × 10 15 Bq at Unit 1, 1.2 × 10 15 Bq at Unit 2, and 1.2 × 10 15 Bq at Unit 3, for a total of 3.4 × 10 15 Bq 4 . As of March 24, 2016, 7.6 × 10 14 Bq was in the storage tanks at the FDNPP site, 2.7 × 10 13 Bq in the reactor building(R/B), and estimated 1.8 × 10 15 Bq was released outside the reactor or in debris (Table 1) www.nature.com/scientificreports/ ...
... Cumulate 3 H yields in the reactors at FDNPP have been estimated to range from 0.01% to 0.0108% 6,7 . According to estimates made immediately after the accident in 2011, there were reports that the inventory of 3 H at the time of the accident was 1.81 × 10 13 Bq 8 , but according to recent reports by Tokyo Electric Power Company Holdings (TEPCO), the inventory of 3 H immediately after the accident was estimated to be 1.0 × 10 15 Bq at Unit 1, 1.2 × 10 15 Bq at Unit 2, and 1.2 × 10 15 Bq at Unit 3, for a total of 3.4 × 10 15 Bq 4 . As of March 24, 2016, 7.6 × 10 14 Bq was in the storage tanks at the FDNPP site, 2.7 × 10 13 Bq in the reactor building(R/B), and estimated 1.8 × 10 15 Bq was released outside the reactor or in debris (Table 1) www.nature.com/scientificreports/ ...
... According to estimates made immediately after the accident in 2011, there were reports that the inventory of 3 H at the time of the accident was 1.81 × 10 13 Bq 8 , but according to recent reports by Tokyo Electric Power Company Holdings (TEPCO), the inventory of 3 H immediately after the accident was estimated to be 1.0 × 10 15 Bq at Unit 1, 1.2 × 10 15 Bq at Unit 2, and 1.2 × 10 15 Bq at Unit 3, for a total of 3.4 × 10 15 Bq 4 . As of March 24, 2016, 7.6 × 10 14 Bq was in the storage tanks at the FDNPP site, 2.7 × 10 13 Bq in the reactor building(R/B), and estimated 1.8 × 10 15 Bq was released outside the reactor or in debris (Table 1) www.nature.com/scientificreports/ There are three possible pathways for the release of 3 H from FDNPP to the outside: ocean, atmosphere, and groundwater. ...
Abstract There has been tritium groundwater leakage to the land side of Fukushima Dai-ichi nuclear power plants since 2013. Groundwater was continuously collected from the end of 2013 to 2019, with an average tritium concentration of approximately 20 Bq/L. Based on tritium data published by Tokyo Electric Power Company Holdings (TEPCO) (17,000 points), the postulated source of the leakage was (1) leaks from a contaminated water tank that occurred from 2013 to 2014, or (2) a leak of tritium that had spread widely over an impermeable layer under the site. Based on our results, sea side and land side tritium leakage monitoring systems should be strengthened.
... 3,4 Therefore, new analytical tools, capable of evaluating the origin and quality of groundwater recharge, are very useful to achieve this aim. 5 Sr and Pb isotopes can be used as environmental indicators of water contamination and for possible identification of its source, [6][7][8][9] as they provide different isotopic signatures. ...
... 37 Therefore, Sr and Pb isotopes can provide information about the solute sources, indicating whether they are anthropogenic or natural. 7 The groundwater isotopic composition is controlled by the chemical composition of the aquifer rocks as well as their ages, 25 the rain, and leakage from pipes. The high precision of isotopic analysis permits the identification of small differences in the isotopic ratios and concentrations, which then characterizes different groundwater sources. ...
... Larger variations were observed for the Sr concentrations (15%), as already described in the literature. 7,25 All Sr isotopic concentrations increased 5-10% after storage in the refrigerator for a month. Filtered samples presented smaller differences between original and duplicate (high reproducibility) Sr concentrations. ...
Few articles deal with lead and strontium isotopic analysis of water samples. The aim of this study was to define the chemical procedures for Pb and Sr isotopic analyses of groundwater samples from an urban sedimentary aquifer. Thirty lead and fourteen strontium isotopic analyses were performed to test different analytical procedures. Pb and Sr isotopic ratios as well as Sr concentration did not vary using different chemical procedures. However, the Pb concentrations were very dependent on the different procedures. Therefore, the choice of the best analytical procedure was based on the Pb results, which indicated a higher reproducibility from samples that had been filtered and acidified before the evaporation, had their residues totally dissolved, and were purified by ion chromatography using the Biorad® column. Our results showed no changes in Pb ratios with the storage time.
... 2004). Gosselin et al. (2004) showed that Sr isotopes can provide information on the sources of solutes within water. Therefore, the Sr isotopic composition of groundwater records an intergrated signal of water-rock interaction along flow path and can be used as a dynamic tracer to constrain subsurface flow patterns. ...
... Since the 1990s, strontium isotopes have been used extensively as a natural tracer of groundwater flow (Peterman and Stuckless, 1992;Bullen et al., 1996;Johnson and DePaolo, 1994;McNutt et al., 1990;McNutt, 2000;Frost et al., 2002;Gosselin et al., 2004;Klaus et al., 2007). Although classified as a trace element, Sr often occurs in measurable quantities in most rock types and behaves geochemically like Ca. ...
The Dongrae thermal water area located at the southeast margin of the Korean Peninsula is one of the oldest hot springs in Korea and has been used in spas since the 9th Century. In this paper, a geochemical significance of 87Sr/86Sr ratios from deep thermal water, groundwater, surface water and rainwater in the Dongrae area is discussed. The bedrock of this thermal water-bearing aquifer is composed of Mesozoic granitoids. For temperatures up to 71°C, the thermal water is Na-Cl type, whereas shallow cold groundwater is Ca(-Na)-HCO3 type. 87Sr/86Sr ratios of the thermal water are in the 0.705651 ± 11-0.705696 ± 12 range and have remained nearly unchanged over the past 4 years (2004-2007). 87Sr/86Sr ratios of the shallow cold groundwater, surface water and rainwater range from 0.705781 ± 26 to 0.705789 ± 12, 0.706700 ± 14 and 0.707375 ± 11 respectively. 87Sr/86Sr ratios of the thermal water in the Dongrae area are lower than those of groundwater, surface water, rain water as well as aquifer bearing granite. These Sr isotopic signatures indicate that the circulation rate between thermal water and current meteoric water, including groundwater, surface water and rain water in the Dongrae area should be very slow. Therefore, the thermal water might be derived from a high temperature paleogroundwater reservoir rather than from circulation of young meteoric water heated by current heat sources. Our data show that 87Sr/86Sr ratios may become an important time lag indicator for the groundwater cycle between deep and shallow groundwater in a fractured granite aquifer system.
... In natural waters, the geochemistry of dissolved Sr is analogous to that of Ca. The Sr isotope fractionations in geochemical processes are considered negligible due to small differences in isotope masses (~ 1 %), and the 87 Sr/ 86 Sr ratios in natural systems mainly reflect geological age and the initial Rb/Sr ratio in the rocks (Gosselin et al. 2004). Thus, in groundwater, the 87 Sr/ 86 Sr ratio often reflects water-rock interaction time or the aquifer matrix if the groundwater contact time is long enough to attain equilibrium. ...
This chapter provides an overview of the stable isotope tracers used in agro-contaminant studies, summarizing essential information about each tracer, including the range of values, sample collection and preparation, and the most common applications. The chapter provides an overview of the book’s concept and contents and refers readers to the chapters of interest.
... The degree to which ion can be used as good indicators of groundwater flow is partly dependent on the ratio of ionic concentration in the fluid relative to that in the rock and the reactivity of the ion in a particular environment (Johnson and DePaolo, 1996;Shand et al., 2007;Shand et al., 2009). For example, where Sr-rich carbonate groundwater moves into a silicate mineral aquifer, the past geochemical evolution of Sr may be retained due to the relatively stable silicate minerals, and thus the inter-aquifer mixing can be depicted in groundwater system at large scales (Armstrong et al., 1998;Cartwright et al., 2010Dogramaci and Herczeg, 2002;Gosselin et al., 2004;Hofmann and Cartwright, 2013;Moya et al., 2016;Petelet-Giraud et al., 2018). In addition, groundwater geochemistry, stable and radiogenic isotopes (e.g. ...
... Studies related to the weathering of silicate rocks and related Fe, Mn, and Sr-Li-Ba distribution in groundwater are sparse. Higher concentrations of Sr, Li, and Ba in groundwater have been observed in carbonate aquifers around the world in countries like Algeria, Egypt, Malawi, China, India, Pakistan, Iraq, Saudi Arabia, Japan, Australia, Serbia, Germany, Russia, USA, and Argentina (Gosselin et al., 2004;de Caritat et al., 2005;Stash et al., 2007: Zuo et al., 2009Mapoma et al., 2016;Santucci et al., 2016;Nakano et al., 2020;Alexeev et al., 2020;Ć uk et al., 2020;Boumaza et al., 2021;Masoud and El-Magd, 2022;Liang et al., 2022;Keesari et al., 2022;Yoshihara et al., 2023). WHO has not fixed a standard value of Sr and Li in drinking water; however, they have fixed the permissible limit for Ba as 0.7 mg/L (BIS, 2012). ...
This study investigates the hydrogeochemistry of groundwater samples collected from the Shiriya River Basin (SRB), a tropical watershed located in Kasaragod, Kerala, southern India., with a special focus on trace elements. Fifty-four groundwater samples were collected from deep aquifers, which constitute weathered and fractured granitoids and mafic rocks, and the groundwater is tapped by bore wells from a fractured zone at a depth range of 60-100 m. Concentrations of Sr, Li, Ba, Al, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, As, Se, Cd, Ag, Au, Te, Pb, Re, and PGEs in groundwater were determined by using Q-ICPMS. Out of the 25 analysed trace elements in groundwater, only Sr (489.6 μg/L), Ba (226 μg/L), Li (11.76 μg/L) Mn (396.8 μg/L), Ni (68 μg/L) and Fe (2438.5 μg/L) show anomalous values. The PGEs and the majority of trace elements show values within the permissible limit. Raman spectral studies reveal the presence of celsian mineral in aquifer rocks and are the source of Ba in groundwater. Further, the XRF data of the rocks show a high enrichment of Fe and Mn in mafic dyke, basalt, and syenite, and Ba and Sr in granite, pegmatite, and granitic gneiss. Therefore, this study proved that the source of these elements is geogenic, i.e., they are released from the crystalline aquifer through rock-water interaction under alkaline conditions. The results of this study show that the groundwater of the basin has enough metals such as Na, K, Mg, Ca, Mn, Fe, Co, Cu, and Zn, which are good for health. Nevertheless, a few metals (Fe, Mn, Ba, Sr, Li, Ni) that may exert toxic effects on humans are also present in the groundwater of the SRB. As groundwater is found to be a dependable source of drinking water in such watersheds, a comprehensive study on the hydrogeochemistry of all watersheds in tropical regions is recommended.
... 연구지역 주변의 바닷물은 2개 지점(SW-1, 2), 강수는 1개 지점(SC-RW-1, 2)에서 채취·분석되었다 (Fig. 1) (Fig. 6(b))를 보 면, 지표로부터 오염 영향을 받지 않아 NO 3 당량 비율 (%)이 작은 지하수는 지하수 연령이 50년 이상 오래된 것으로 나타나며, NO 3 당량 비율(%)이 커지면 지하수의 연령은 젊어지는 경향성을 보인다. 이는 Fig. 6 (Faure and Powell, 1972;Aberg etl., 1990;Martinelli et al., 1996;Clark and Fritz, 1997;Gosselin et al., 2004 (1) 지하수의 EC 값은 111~21,000 μS/cm로서 폭넓은 범위를 보였으며, 수질 유형은 Ca(Mg)-Cl(or NO 3 ), Ca(or Na)-HCO 3 , Ca(or Na)-HCO 3 (Cl), Na-Cl(HCO 3 ), Na-Cl 유 형 등 매우 다양하게 나타난다. 지하수의 수질 유형은 길 산천의 중상류 → 중류 → 하류 지역으로 가면서 Ca(Na)-HCO 3 (Cl) → Na(Ca)-Cl(HCO 3 ) → Na-Cl 유형으로 점진 적으로 변화해 가는 경향성을 보인다. ...
... mol %이다. 이들에 의하면, 세계 여러 지역의 Sn-W-Mo 광화대에서는 액체 CO 2 를 함유하는 유체포유 물이 광물 내부에서 많이 관찰되고 있으며 (Takenouchi, 1971;Higgins, 1980), Park and Park(1979) 과 Park et al.(1981) (So et al., 1983;Park et al., 1985a (Åberg et al., 1990;Drever, 1997;Gosselin et al., 2004 3.5. CO 2 성분의 기원, 부존지역과 물순환에 대한 고찰 3.5.1. ...
... To study groundwater flow dynamics, recharge and residence times in fractured rocks with hydrological discontinuities, environmental tracers are a valuable tool because their interpretation does not require assumptions of a porous medium (i.e., continuum approach Singhal & Gupta, 2010). Water isotopes (δD and δ 18 O) and strontium isotopes ( 87 Sr/ 86 Sr) are effective natural tracers for groundwater origin and flow in catchment studies (Cartwright, 2010;Cartwright et al., 2007;Frost & Toner, 2004;Gosselin et al., 2004). Strontium isotopes are not fractionated by geochemical reactions or biotic processes. ...
Groundwater dynamics in continental rift zone settings remain poorly understood because of the spatial heterogeneity in flow, storage, and recharge dynamics. The Central Kenya Rift is an excellent example where, though groundwater is important for domestic, irrigation, and geothermal energy exploitation, its hydrogeological properties remain largely unknown. Existing conceptual groundwater models assume flow from the high‐elevation, humid rift flanks to the low‐elevation, semiarid rift floor, but the role of the faults that fracture the aquifers is commonly unaccounted for. We applied geochemical, isotopic (δ¹⁸O, δD, ⁸⁷Sr/⁸⁶Sr, ³H‐³He), multivariate statistical methods, and knowledge of geological structures to determine recharge sources, flow, and residence times to revise the conceptual flow model. Results show that groundwater is primarily recharged by meteoric waters, river input, and Lake recharge. The faults impart a control on the groundwater flow within four sub‐compartments. Major differences in flow patterns exist between the eastern and western rift flanks: surface and groundwater transfer from the eastern flanks to the rift floor occurs via relay ramp structures, and flow on the west side takes place laterally from the high escarpment. Although ³H‐³He dating shows that the age of groundwater ranges from a few to >>50 years, most of the groundwater in the rift‐floor area is free of ³H and was recharged before the 1960s. Hence, we propose that these areas receive episodic recharge and represent the most sensitive groundwater resources in the rift. To inform sustainable groundwater development, a robust monitoring network is required to capture the heterogeneous groundwater dynamics.
... Volcanic rocks located southeast part of the study area (Fig. 1) show the presence of strontium in various lava assemblages associated with calcic plagioclases (Garcia-Tovar and Martinez-Serrano, 2011), so, it can be assumed that the release of Sr and Ca to the water is related to the alteration of these minerals ( Fig. 4a and d). Both, Sr and Ca, can be used to identify water-rock interaction processes and to define flow pathway systems, mainly by assessing the isotopic signature of dissolved Sr (Taylor et al., 1981;Gosselin et al., 2004;Wallin 1999, Wiegand et al., 2001). In granitic rocks, the Ca and Sr carriers are plagioclases and amphibole (Land and Ö hlander, 2000;Kaleem et al., 2021), but there is a greater affinity for plagioclases (Stueber, 1978). ...
The intensive use of the Aquifer of the Metropolitan Zone of Mexico City (AMZMC) has increased the concentrations of some trace elements due to natural or anthropogenic sources, as the release of elements from the heterogeneous mixture of the volcanic rocks and/or alluvial clay deposits, which play a very important hydrogeological role in the behavior of the aquifer. This study characterizes, examines, and compares the concentrations of Ba, B, Sr, and Rb in some wells of the AMZMC. Characterization of major elements and Ba, B, Sr concentration and their behavior in the aquifer, and some ionic ratios have been used to identify the dominant hydrogeochemical processes and the different sources of Rb, Ba, B, Sr in the water, in which mineral alteration, ion exchange, redox reactions are the dominant processes, and may intensify as the salinity, temperature and ionic strength in the medium increases. This information may be indirectly relevant as a contribution to the development of appropriate water management strategies in Mexico City. In addition to providing new data on the distribution and behavior of Rb, Ba, B, Sr in groundwater of the Mexico City Aquifer, which is used for drinking water supply.
... In contrast, connate water leakage generally occurs in inland areas, where the depression cone allows connate water located on top of freshwater to recharge the deep freshwater layer throughout the aquitard (i.e., especially for a thin aquitard) under hydrodynamic drive, leading to increased salinity in the deep aquifer (Han et al., 2012). In rare cases, groundwater salinization can be caused by water-rock interaction dissolution from evaporated salt deposits in some coastal plains (Gosselin et al., 2004;Moussa et al., 2011;Meng et al., 2019). ...
In most coastal alluvial plains, the groundwater area of the aquifer is a rich environment that has experienced an extended period of marine deposition and is highly vulnerable to increasing urbanization. Excessive exploitation of groundwater has resulted in recent seawater intrusion and connate water leakage, leading to freshwater salinization. In this study, a novel workflow is designed for groundwater appraisal. First, revised one-dimensional direct transformation schemes were developed and applied to extensive vertical electrical sounding (VES) points sampled by a Schlumberger array to obtain the VES-based calibrated transformed resistivity (V-CTR), as calibrated by the modified reflection coefficient and novel depth correction factor. Next, the interfaces of all leaky confined aquifers (LCAs) and the saline water zone were quantitatively determined via hybrid interpretation methods. Finally, to better understand the salt level (i.e., fresh, brackish, or saline) and perform assessments of the groundwater quality, total dissolved solids (TDS) planar distributions were interpolated using two different power functions linking the V-CTR and measured TDS from the sampled boreholes for the corresponding aquifer unit. The workflow was examined based on hydrological and geophysical data acquired at the Yangtze River Delta (Nantong Region, Jiangsu Province, China). The interpreted results are of great significance for understanding the groundwater distribution associated with the Quaternary geology and hydrogeology and can be potentially used to analyze and guide the development and utilization of water resources in the study area.
... To constrain the lithology dependence during WRI, we conducted strontium (Sr) analysis from the manifestation, the well fluid and the well rock samples. The Sr isotope ratio ( 87 Sr/ 86 Sr) is well regarded as an effective indicator of flow patterns, groundwater-rock interaction, and physicochemical processes in deep regions (Peterman and Wallin, 1999;Gosselin et al., 2004). Rocks of different chemistries and ages release strontium into surface waters by chemical weathering (Steele and Pushkar, 1973). ...
Determinations of the recharge area and recharge mechanism in geothermal systems are essential for reservoir management and a sustainable resource use. To address this problem, studies aplenty have aimed to identify the recharge elevation using stable water isotopes, δ²H and δ¹⁸O. Nevertheless, the physical and chemical processes involved in the generation of a reservoir fluid from a deeply infiltrated recharge flow remain poorly understood. This study aims to clarify this process using strontium (Sr) concentrations and isotope composition from water and well rock samples by selecting a geothermal field with a two-phase reservoir system in Southern Bandung, West Java, Indonesia. The water samples are characterized by variable Sr isotopic compositions (⁸⁷Sr/⁸⁶Sr) (0.70450–0.70725) and low Sr concentrations (0.01–0.72 ppm). The ⁸⁷Sr/⁸⁶Sr of the well rocks is also variable (0.70400–0.70827) with particularly high Sr concentrations (9.1–53 ppm). Three types of domain that are the combinations of the reservoir fluid mixing with groundwater are identified. The first two types are shallow and deep groundwater composed of 90 % meteoric water and 10 % upflow fluids with Sr concentration 0.01 to 0.11 ppm and the ⁸⁷Sr/⁸⁶Sr from 0.7055 to 0.70725. The shallow groundwater may possibly carry a ⁸⁷Sr/⁸⁶Sr anomaly (higher than ⁸⁷Sr/⁸⁶Sr of plagioclase: 0.7065) from the anthropogenic activities through the pathways created by the intersection of the NW-SE and NE-SW inferred regional faults in the west part of the field, hosted by the Wayang Windu Formation. The deep groundwater type is also a mixture of 10 % parent fluid hosted by the deeper aquifer rocks Malabar Formation, with lower strontium isotopes ratio than the first aquifer (⁸⁷Sr/⁸⁶Sr 0.7045–0.7055). The third groundwater refers to the perched aquifer with mixture of 30 %–70 % parent fluid that has undergone condensation and mixing processes in Pangalengan Formation (⁸⁷Sr/⁸⁶Sr 0.70452–0.7052). This groundwater is thought to be the source of mostly hot springs in the study area.
... For example, Radon-222 concentrates in subsurface waters (Dimova, Burnett, Chanton, & Corbett, 2013) and can therefore be used to investigate river/groundwater mixing (Bertin & Bourg, 1994) and groundwater discharge in coastal areas and lakes (Cable, Burnett, Chanton, & Weatherly, 1996;Dimova et al., 2013). Stable strontium isotopes ( 87 Sr/ 86 Sr) have been used effectively as groundwater tracers (Bullen, Krabbenhoft, & Kendall, 1996;Gosselin, Harvey, Frost, Stotler, & Macfarlane, 2004;Gunn, Bottrell, Lowe, & Worthington, 2006), including in the context of unconventional hydrocarbon resources (Chapman et al., 2012;Frost, Pearson, Ogle, Heffern, & Lyman, 2002). The ratios of stable oxygen ( 18 O/ 16 O) and ...
An environmental concern with hydraulic fracturing for shale gas is the risk of groundwater and surface water contamination. Assessing this risk partly involves the identification and understanding of groundwater‐surface water interactions because potentially contaminating fluids could move from one water body to the other along hydraulic pathways. In this study we use water quality data from a prospective shale gas basin to determine: if surface water sampling could identify groundwater compartmentalisation by low‐permeability faults; and if surface waters interact with groundwater in underlying bedrock formations, thereby indicating hydraulic pathways. Variance analysis showed that bedrock geology was a significant factor influencing surface water quality, indicating regional‐scale groundwater‐surface water interactions despite the presence of an overlying region‐wide layer of superficial deposits averaging 30–40 m thickness. We propose that surface waters interact with a weathered bedrock layer through the complex distribution of glaciofluvial sands and gravels. Principal component analysis showed that surface water compositions were constrained within groundwater end‐member compositions. Surface water quality data showed no relationship with groundwater compartmentalisation known to be caused by a major basin fault. Therefore, there was no chemical evidence to suggest that deeper groundwater in this particular area of the prospective basin was reaching the surface in response to compartmentalisation. Consequently, in this case compartmentalisation does not appear to increase the risk of fracking‐related contaminants reaching surface waters, although this may differ under different hydrogeological scenarios.
... Now they are increasingly used to identify Ca sources due to the similar chemical behaviour of Sr and Ca (Åberg et al., 1989;Gosz and Moore, 1989;Wickman and Jacks, 1992;Bailey et al., 1996;. Åberg et al. (1989), Wickman and Jacks (1992), Bain and Bacon (1994), , , Harrington and Herczeg (2003) studied weathering processes and Frape et al. (1984), Kay and Darbyshire (1986), Négrel et al. (2003) and Gosselin et al. (2004) water-rock interactions in watersheds using Sr isotope ratios. The impact of atmospheric inputs on water quality in watersheds was investigated by Graustein and Armstrong (1983), Gosz and Moore (1989) and . ...
From a biogeochemical perspective, catchments can be regarded as reactors that transform the input of various substances via precipitation, deposition, or human activities as they pass through soils and aquifers towards receiving streams. Understanding and modeling the variability of solute concentration in catchment waters require the identification of prevailing processes, determining their respective contributions to the observed transformation of substances, their interplay with hydrological processes, and the determination of anthropogenic impacts. However, numerous biogeochemical processes often interact in a highly non-linear way and vary on temporal and spatial scales, resulting in temporally and spatially varying water chemistry in catchments. This is particularly true for riparian wetlands. Processes in this catchment area often superimpose the influence of the hill slope (and largest) area of the catchment on surface water quality. Accordingly, the first part of this thesis (Study 1 and 2), focuses on the temporal and spatial variability of biogeochemical processes at the catchment scale. Therefore, the first aim was to identify the prevailing biogeochemical processes which affect the quality of catchment waters in two forested granitic catchments. Based on these results, (i) the long-term behavior of these processes was determined (Study 1) and (ii) hot spots of these processes at the catchment scale along different flow paths were identified (Study 2). The second part (Study 3) focuses on the interplay between hydrological and biogeochemical processes in a riparian wetland, with the aim of systematically tracing back the temporal patterns of stream water chemistry to different biogeochemical processes and antecedent hydrological boundary conditions in the wetland. The third part (Study 4 and 5) focuses on weathering processes with the goal (i) of identifying the mineralogical sources of the groundwater’s buffer capacity against acid atmospheric deposition in a forested granitic catchment and (ii) determining the mineralogical sources of the high cation loads in surface water, induced by intensive agricultural activities in two agricultural granitic catchments. To reach these aims, multivariate statistical methods of dimensionality reduction (linear Principal Component Analysis, non-linear Isometric Feature Mapping), a low-pass filtering of time-series, a Cluster analysis, and major and trace element ratios and strontium isotopes were used. A small number of biogeochemical process bundles explained 94% and 89% of the variance of the data set in Study 1 and 2, respectively. In Study 1, redox and topsoil processes, road salt and sulfate contamination were identified as predominating processes influencing water chemistry in the respective catchments. Low-pass filtered time series of component scores revealed a different long-term behavior at different sampling sites in both catchments, which could be traced back to the fraction of wetland area in the respective subcatchments as well as by the varying thickness of the regolith. Study 2 revealed that the upper 1 m topsoil layer could be considered as a biogeochemical hot spot for redox processes, acid-induced podsolization, and weathering processes along different flow paths. Up to 97% of the biogeochemical transformation of the chemical composition of soil solution, groundwater and stream water in the Lehstenbach catchment was restricted to this soil layer representing less than 2% of the catchment’s regolith. Wetland stream water, mobilized in the topsoil layer being considered a biogeochemical hot spot, showed a highly dynamic temporal pattern of component scores. Study 3 revealed four different types of wetland stream water chemical status, depending on the interplay between discharge dynamics, biological activity, and the water table position in the wetland. The sequence of different stream water types roughly followed a seasonal pattern, albeit being heavily modified by the respective hydrological boundary conditions for different years. Extended periods of low groundwater level in the second half of the growing season drastically changed the chemical boundary conditions, becoming evident in a drastic reoxidation of reduced species like sulfides and corresponding effects. Weathering processes are one of the predominating biogeochemical process bundles influencing water chemistry in forested catchments. Study 4 showed that the mineralogical sources of the groundwater’s buffer capacity against acid atmospheric deposition were dominated by the release of base cations from apatite dissolution, preferential cation release from feldspars and biotite, and feldspars weathering. In Study 5, determining the mineralogical sources of the high cation loads in surface water induced by intensive agricultural activities revealed a dominant manure contribution in the topsoil, and enhanced mineral dissolution (plagioclase and biotite) by fertilizer application in subsoils, becoming the unique source of base cations in the saprolite. Stream water chemistry differed from that of soil water, suggesting that stream water chemistry was dominated by elements issued from enhanced mineral and rock weathering. Soil acidification induced by agriculture allows the mobilization of cations stored in soil layers, enhances the rock weathering and accelerates plagioclase dissolution, which can highly influence stream water quality. Numerous biogeochemical, hydrological, and anthropogenic processes were found to interact with each other, mostly with non-linear patterns, influencing catchment water chemistry. The integral approach used in this thesis would be a useful prerequisite to develop accurate and parsimonious models commonly used for water management purposes by distinguishing between short- term and long-term shifts, reducing the number of processes to the predominating ones ultimately to be included in the model, focusing on hot spots and including spatial patterns where necessary and appropriate.
... Unlike the oxygen and hydrogen, strontium (Sr) is a non-conservative element, which means that the isotopic concentration and composition varies according to the rock-water interaction: if the interaction time is long, the water tends to reach the isotopic equilibrium with the rock. Even if this technique is widely adopted in hydrogeology [2,5,[82][83][84][85][86][87][88][89][90][91][92][93][94], for the Classical Karst Region waters no references can be found until now. So, data concerning the strontium isotope ratio ( 87 Sr/ 86 Sr) in Classical Karst Region waters are here presented for the very first time. ...
The study of the different hydrogeological compartments is a prerequisite for understanding and monitoring different fluxes, thereby evaluating the environmental changes in an ecosystem where anthropogenic disturbances are present in order to preserve the most vulnerable groundwaters from contamination and degradation. In many karst domains in the Mediterranean, areas groundwaters and surface waters are a single system, as a result of the features that facilitate the ingression of waters from surface to subsurface. This is also the case for the Classical Karst hydrostructure, which is a carbonate plateau that rises above the northern Adriatic Sea, shared between Italy and Slovenia. The main suppliers to the aquifer are the effective precipitations and the waters from three different rivers: Reka/Timavo, Soča/Isonzo and Vipava/Vipacco. Past and ongoing hydrogeological studies on the area have focused on the connections within the Classical Karst Region aquifer system through the analysis of water caves and springs hydrographs and chemographs. In this paper, the authors present new combined data from major ions, oxygen, hydrogen and strontium stable and radiogenic isotopes which have allowed a more complementary knowledge of the groundwater circulation, provenance and water-rock interactions. All the actions occurred in the framework of the European project HYDROKARST.
... These elements may be supplied by the dissolution of the amphiboles and feldspars that compose the matrix of the semi-confined aquifer. If water originating from seawater intrusion has high temporal permanence in the aquifer, it is to be expected that its Li and Sr concentrations should rise as the contact time between sea water and the aquifer matrix increases (Brondi et al., 1973;Tulipano and Fidelibus, 1984;Gosselin et al., 2004;Somay and Gemici, 2009). On the other hand, Se is an abundant element in coastal plain sediments and it tends to be desorbed from the solid phase of the aquifer to pH values close to 8. When it enters into solution, it forms oxyanions that increase Se concentration as the water-rock contact time increases (Massee and Maessen, 1981;Vengosh, 2003). ...
The hydrochemistry of minor elements and traces such as bromide, lithium, strontium, uranium and selenium, together with the chemical analysis of major ions, has been used in the study of salinization process. This process occurs in a semi-confined aquifer that corresponds to a Pliocene–Pleistocene fluvial environment. The semi-confined aquifer is located in the littoral of the cities of Ensenada and Berisso, in the region of the middle Río de la Plata estuary, Argentina. Groundwater salinization was detected in the semi-confined aquifer in the coastal plain area, with salt contents that increase from the loess plain towards the river. The content of major ions that predominate in sea water (Cl−, Na+ and Mg2 +), as well as the Cl−/Br− and U vs. Cl− ratios, demonstrates that such salinization is related to sea water, which shows no correspondence with estuary water. In the salinized area, Li, Sr and Se enrichments occur, and are used as tracers of the average time that a substance remains in solution in sea water in the aquifer. The study of such minor ions together with the geological evolution of the area made it possible to recognize that the salt water in the semi-confined aquifer corresponds to a palaeo-intrusion of sea water associated with the Pleistocene–Holocene ingressions caused by the climate changes occurring during the Quaternary.
... Most importantly, broad areas have ratios with ratios between 0.707 and 0.709 (Groschen and Buszka, 1997;Kreitler et al., 2013;Musgrove et al., 2010aMusgrove et al., , 2010bUliana et al., 2007;Wong et al., 2014). Similarly low ratios are seen in Kansas where values are mostly between 0.708 and 0.709 and none are above 0.7092 (Gosselin et al., 2004). If the skulls and mandibles were coming from the Southern Plains, we would expect to see many people with ratios between 0.707 and 0.709, yet none of the 66 individuals have values that low. ...
The 352 individuals from a skull and mandible cemetery at the Crenshaw site (3MI6) in southwest Arkansas have been argued to represent non-Caddo victims of warfare from other regions. Strontium isotopes taken from 80 individuals were processed as part of a NAGPRA grant and have been used to claim they supported evidence of interregional warfare between the Caddo and groups in the Southern Plains. A second analysis suggested that the strontium isotopes were subject to diagenesis and unusable for interpretations. A reanalysis of the results and comparison with recent literature shows that the strontium isotope results are valid. This article demonstrates the importance of considering context during analysis. The deer and people from different times and contexts have different strontium isotope ratios. Going beyond evaluating if they are local or non-local, this difference shows the potential for strontium isotope ratios to document settlement pattern change through time. Computing the biologically available strontium range using the mid-range of comparative samples (instead of the mean) is offered as a more theoretically appropriate method for investigating populations suspected of coming from the hinterlands or surrounding sites, such as those at Crenshaw. When the mid-range method is used, all individuals match the local range. Strontium isotopic data from other regions including the Midwest and Southern Plains suggest that the skulls and mandibles were not likely coming from these regions. Instead, it is hypothesized that they represent a local burial practice associated with a dispersed settlement pattern at the time the Caddo were adopting maize as a staple.
... d 34 S is especially useful for studying biogeochemical processes in groundwater (e.g., Kaplan and Rittberg 1964;Sim et al. 2011). d 87 Sr can be used due to the geochemical properties for hydrogeological investigation such as groundwater-rock interaction process and groundwater flow path system, in which water may retain the rock signature in its dissolved Sr (Gosselin et al. 2004;Wallin 1999, Wiegand et al. 2001). In case of low temperature (12-14 C) fluids like in € Asp€ o, this process is strongly dependent on the mineralogical composition of the investigated host rock, the salinity and the residence time of the fluid (Fritz et al. 1991;Glodny and Grauert 2009;M€ oller et al. 1997). ...
The 450 m deep Äspö Hard Rock Laboratory (Äspö HRL) provides a unique opportunity to access different aquifer systems within the Precambrian granodioritic basement of the Baltic Shield. In this study, emphasis will be placed on systematic variations of the isotopic and chemical composition including fractionation patterns of rare earth elements (REE) of three different aquifers. The aim is to identify end-member groundwater compositions and increase the knowledge and understanding of the groundwater evolution, and water rock interaction, parameters which are important for the subsurface microbial activity in the Äspö HRL. Groundwaters at the shallow and intermediate aquifers were influenced most from Baltic Sea water and meteoric water. The analyses of Sr-data and REE show especially long-term groundwater-rock interaction and δ18O values indicate the presence of glacial meltwater in the deep aquifer. During the 5 years of investigation, significant chemical changes caused by internal mixing processes or present microbial activity were not observed.
... Though, the 87 Sr/ 86 Sr composition may be influenced by exogenous sources like fertilizers that show large variations in isotopic compositions and concentrations (Böhlke and Horan, 2000;Négrel et al., 2004;Pierson-Wickmann et al., 2009;Vitòria et al., 2004). Owing to its conservative behavior in groundwater systems, Cl can be coupled to Sr to better understand the prevailing processes (Gosselin et al., 2004). Major elements, such as Na, K, and Cl, are essentially used to trace anthropogenic contaminations, such as WWTP or landfill contributions (Andersen et al., 2004). ...
The objective of this study is to identify the origin of groundwater in a shallow alluvial aquifer, using a multi-tracer approach including δ18O, δ2H, major elements and 87Sr/86Sr. In addition, triazines are used as a tracer of water draining agricultural areas.
Four potential recharge sources are evidenced in the alluvial groundwater: rainfall, karst water from adjacent aquifer, imported Rhône river water and local stream water.
Strontium isotopes are used to highlight the adjacent karst water input (Sr = 6.4 - 17.6 µmol.L-1; 87Sr/86Sr = 0.7076 – 0.7078) showing a contrasting signature with the pristine alluvial groundwater (Sr = 3.4 µmol.L-1; 87Sr/86Sr = 0.7088 – 0.7092). Lateral karst recharge is observed, with high proportions reaching 100%, all along the North Western border of the aquifer. This lateral recharge implies a dilution in triazines content of the Vistrenque groundwater as the karst area is not used for agriculture.
Oxygen-18 and deuterium signatures of local rainwater (δ2H = -43.5 ‰) and imported Rhône River water (δ2H = -72.5 ‰) differ significantly which allows to quantify the influence of imported water on the alluvial groundwater. Such influence is observed only locally in this study. Contribution of local stream water, influenced by wastewater treatment plant effluents, is also locally detected in the alluvial aquifer, using Cl, K, and Na contents.
High triazines, NO3, and Cl concentrations underline the vulnerability of this shallow alluvial aquifer to surface contaminations. Finally, the results of this environmental multi-tracer approach are statistically supported by principal component analyses.
... To hipotezo, čeprav zasnovano le na enkratnem vzorčenju, potrjujejo tudi predhodne raziskave (Doctor, 2000). (Palmer & Edmond, 1992;Johnson & DePaolo, 1994;Oetting et al., 1996;Gosselin et al., 1997;Armstrong & Sturchio, 1998;Johnson et al., 2000;Gosselin et al., 2004;Négrel & Petelet-Giraud, 2004;Han & Liu, 2004;Katz & Bullen, 1996;Musgrove & Banner, 2004;Barbieri et al., 2005;Musgrove et al., 2010) (Krivic et al. 1986;Flora & Longinelli 1989;Urbanc & Kristan, 1998;Doctor et al., 2000Doctor et al., , 2006Doctor, 2008;Urbanc et al., 2012). Questa ipotesi abbozzata su un singolo campionamento, trova tuttavia conferma negli studi di Doctor (2000). ...
Dopo quasi 200 anni dalle prime ricerche sul Timavo, prende il via il
Progetto HYDROKARST nato dalle idee di ricercatori italiani e sloveni
che da anni studiano insieme l’idrogeologia carsica (www.hydrokarstproject.
eu). Il progetto ha come obiettivo la gestione coordinata e la tutela
dell’acquifero transfrontaliero del Reka-Timavo attraverso l’istituzionalizzazione
di una rete di monitoraggio quantitativo e qualitativo delle
acque ipogee e del territorio del Carso Classico.
Il progetto si propone di garantire, attraverso delle partnership stabili,
una gestione sostenibile della risorsa acqua rafforzando quella coesione
territoriale transfrontaliera che deve portare alla redazione di protocolli
congiunti per permettere di uniformare le metodologie di raccolta
dati e la loro rappresentazione e codifica, primo passo per la definizione
delle aree di salvaguardia delle sorgenti e dei pozzi captati a scopo
idropotabile. Va ricordato che ad oggi, le acque del Reka-Timavo non
sono legalmente tutelate, cosa che invece accade per quelle del fiume
Isonzo-Soča.
... The 87 Sr/ 86 Sr ratio of the groundwater mirrors that of the rocks through which the groundwater has flowed (Uliana et al., 2007). The 87 Sr/ 86 Sr ratio can be used to investigate the geochemical evolution and flow path of the groundwater (Armstrong and Sturchio, 1998; Barbieri et al., 2005;Gosselina et al., 2004;Negrel, 2006), and to study the relationship between surface water and groundwater (Ojiambo et al., 2003). The presence of 87 Sr in rocks is caused mainly by the radioactive decay of the 87 Rb (87-Rubidium) isotope, and groundwater which is in chemical equilibrium with rocks rich in the Rb isotope commonly has a high 87 Sr/ 86 Sr ratio. ...
A geological and hydrogeological survey was performed in the upper alluvial and proluvial fan and the northern mountain area of the Chaobai River in Beijing. Samples of local precipitation, surface water and groundwater (including spring discharges, groundwater from the fractured bedrock, and shallow and deep groundwater of the alluvium) were collected and analysed to assemble hydrochemical and isotopic data. Q-mode hierarchical cluster analysis (HCA) was used to classify the groundwater samples from multiple aquifers into objective groups. Two groups and six subgroups with distinct groundwater recharge sources, flowpath histories and geochemical evolution histories were identified. Inverse geochemical modelling was adopted to study the deep groundwater chemical evolution. Hydrochemical data and isotopic data on H-2, H-3 and O-18 were used to evaluate groundwater recharge, flowpath histories and geochemical evolution, and Sr-87 was used to provide further insight into groundwater recharge sources and flow directions. It was found that particularly in areas of groundwater cones of depression, the deep alluvial groundwater may be partly derived from the groundwater of the underlying fractured bedrock. The phreatic, or unconfined, groundwater within the northern area of the alluvial and proluvial fan is sustained mainly by the lateral flow of groundwater from the piedmont regions and by recharge from surface water bodies such as the Miyun reservoir. The shallow alluvial groundwater within the central and southern areas of the alluvial and proluvial fan is recharged primarily by the local precipitation and agricultural irrigation. The deep alluvial groundwater within the central and southern areas of the fan is sustained chiefly by the flow of groundwater from the northern area of the fan or from the underlying fractured bedrock. Methodologies adopted in this work may be useful to future investigation of groundwater in multiple aquifer systems similar to this area.
... Strontium (Sr) isotopes have been used effectively as a tracer for water-rock interaction in numerous drainage basin and groundwater system studies (e.g., Lyons et al., 1995;Négrel et al., 1997;Armstrong and Sturchio, 1998;Petelet et al., 1998;Böhlke and Horan, 2000;Pennisi et al., 2000;Probst et al., 2000;Aubert et al., 2002;Douglas et al., 2002;Banner, 2004;Gosselin et al., 2004). Because strontium is an alkaline earth element with an atomic radius near that of calcium (Ca) for which it commonly exchanges, it is frequently used as a proxy for Ca in geologic and hydrologic systems. ...
... 지하수내 Na, Ca, Sr 등과 같은 용존성분은 물-암 석 반응의 결과로서, 지하수에서의 87 Sr/ 86 Sr값은 물속 의 용질의 기원에 대한 정보를 제공해주며 (Gosselin et al., 2004), 특히 심성암지역에서의 심부지하수내 87 Sr/ 86 Sr값은 사장석과의 반응에 의한 결과로서 알려져 있다 (Franklyn et al., 1991 (Lee et al., 1994(Lee et al., , 2005(Lee et al., , 2010김용준과 이대성, 1983;김남훈 외, 2002강지훈 외, 2004, 2006정창식 외, 2004;정원석, 나기창, 2008;정원석 외, 2009;이호선 외, 2010). Lee et al. (2005) (Masuda et al., 1973;Masuda, 1975) and (d) -(f) Primitivemantle (Sun and McDonough, 1989) normalized spider diagram for the trace elements in the Deokgu leucogranite. ...
Here we report major element composition, trace and rare earth element abundance, Sm-Nd and Rb-Sr isotopic composition from Deokgu leucogranite. Chondrite-normalized REE pattern and its Eu anomaly are divided into 3 types systematically, and have close relationship with contents. Such geochemical characteristic indicates that the leucogranite was derived by feldspar fractionation from a common source magma. Sm-Nd and Rb-Sr whole rock ages are (initial ; ) and (initial ), respectively. Initial value indicates that the magma should be derived from the crustal material. This initial value also corresponds well with those from the Precambrian granitoids from North-China Craton rather than those of South-China Craton.
... Finally, the very long half-life of 87 Rb compared with typical groundwater residence times of <1 Ma means that there is essentially no change in 87 Sr/ 86 Sr ratios due to the decay of 87 Rb in groundwater (Cartwright et al., 2007). 87 Sr/ 86 Sr is widely used to trace ion sources in natural water (Palmer and Edmond, 1992;Bickle et al., 2005;Xu and Liu, 2007;Chetelat et al., 2008;Rengarajan et al., 2009;Jiang and Ji, 2011), the mixing processes of groundwater (Bullen et al., 1996;Négrel et al., 2003;Frost and Toner, 2004;Rango et al., 2010), the flow paths of groundwater (Frost et al., 2002;Gosselin et al., 2004;Cartwright et al., 2007;Shand et al., 2007), contamination in groundwater (Böhlke and Horan, 2000;Li et al., 2010;Jiang, 2011), and watererock interactions (Bottomley et al., 1994;Négrel et al., 2001Négrel et al., , 2004Frost and Toner, 2004;Shand et al., 2009;Jin et al., 2010a). The study of 87 Sr/ 86 Sr in groundwater may improve understanding of ion sources and provide a basis for understanding watererock interactions. ...
Major ions, isotopic ratios of strontium (Sr-87/Sr-86), hydrogen (delta D) and oxygen (delta O-18) of groundwater samples were analyzed to decipher spatial variation, controlling factors, solute sources, and the recharge source of shallow groundwaters within the Lake Qinghai catchment. Shallow groundwaters in this area are slightly alkaline, with 97% being fresh water of good quality, though there are high concentrations of nitrate and sulfide in Buha and lakeside groundwaters. Most of the shallow groundwaters are of the Ca2+-HCO3- type, whereas part of groundwaters surrounding the lake (LS) belongs to the Na+-Cl- type as lake water (QHL). Groundwater geochemistry is controlled by regional lithological association, ion exchange, and mineral precipitation. The dissolved Sr concentrations and Sr-87/Sr-86 ratios vary from 1.0 to 15.6 mu mol/L, and from 0.709859 to 0.715779, respectively. The first quantitative calculation in groundwater using a forward model shows that 40% of dissolved Sr is from carbonate weathering, 33% from evaporite dissolution, 17% from silicate weathering, and the remainder from atmospheric input for the whole catchment. Carbonate weathering dominates groundwater geochemistry in Shaliu (SL), Hargai (HG) and Buha (BR) samples, while evaporite dissolution dominates LS and Daotang (DT) samples. delta D and delta O-18 data show that rain water is the major recharge source of both river water and shallow groundwater within the Lake Qinghai catchment. Qinghai Lake water is characterized by Buha-type water, but its Sr geochemistry is different from the shallow groundwater due to carbonate precipitation. Although shallow groundwater contributes similar to 5% of the dissolved Sr to the QHL, groundwater must be taken into account when the chemistry and budget of lake water are characterized.
... Since WRI has an important control on strontium enrichment, strontium isotope ratios have been widely used for investigating the WRI occurring in groundwater systems (Oetting et al. 1996;Armstrong et al. 1998;Woods et al. 2000). In addition, strontium isotope ratios frequently serve as tracers for delineating recharge sources and mixing processes in groundwater system; representative studies including Lyons et al. (1995), Katz and Bullen (1995), Gosselin et al (2004), and Wang et al (2006). For Hebei Plain, deep groundwater is the most important source of water supply in the region. ...
In Hebei plain, the most important source of water supply is groundwater, which as system, can be divided into 7 aquifers. In this study, major ion hydrochemistry and 87sr /86sr ratios data were analyzed in order to understand strontium isotope evolution mechanism of groundwater in the Hebei plain. Based on integrated analysis, it is considered that the radiogenic Sr in groundwater from quaternary sediments (Q4- Q1) comes from the weathering of silicate mineral rich in Na and Rb. The 87 Sr/86Sr ratios increase systematically with the increasing age and depth of groundwater, and this reflects "the accumulative effect of time" to water-rock interaction. Although the low 87Sr/86Sr ratio of groundwater is associated with the low content of Rb in the rocks, further research is required to reveal its evolution mechanism. (The Journal Of American Science. 2007;3(4):1-6). (ISSN: 1545-1003).
... granite and gneiss) have 87 Sr/ 86 Sr ratios ranging between 0.7135 and 0.717 and 87 Sr/ 86 Sr ratios of modern seawater are around 0.7092 (Faure, 1986;Négrel and Roy, 1998;Negrel et al., 1988). The contribution of seawater strontium to a given groundwater sample can be estimated from the ratio of chloride to strontium (Cl/Sr) (Gosselin et al., 2004;Négrel et al., 2001). Groundwater samples in Group 1 have 87 Sr/ 86 Sr values ranging from 0.709678 to 0.712153, with Cl/Sr ratios (Fig. 8) higher than when influenced by silicate weathering or seawater intrusion. ...
Surface water and groundwater chemistry of the coastal aquifer systems in south-eastern Tanzania have been studied with a focus on isotopes and major ions, in order to assess the controlling hydrological and geochemical processes. ⁸⁷Sr/⁸⁶Sr isotope ratios have provided information about the hydrology that could not have been obtained by studying the physical and chemical characteristics of water quality alone. The data reveal a rather complex mixing pattern of various water source end-members that are subject to different hydro-geochemical processes, such as evaporation, weathering and other water–rock interactions, and seawater intrusion, which control the water quality. Data on ⁸⁷Sr/⁸⁶Sr ratio distribution and strontium (Sr2 +) concentration delineate three types of groundwater in the coastal aquifer system:
... To complement major elements, isotopic data on elements such as O, H, Sr, and sometimes S, are widely used to identify end-members involved in the groundwater signature (e.g. Armstrong et al., 1998; Gosselin et al., 2004; Brenot et al., 2008; Raiber et al., 0883-2927 2009). In order to identify the origin of salinity, the use of elemental and isotopic compositions of B (e.g. ...
... To complement major elements, isotopic data on elements such as O, H, Sr, and sometimes S, are widely used to identify end-members involved in the groundwater signature (e.g. Armstrong et al., 1998; Gosselin et al., 2004; Brenot et al., 2008; Raiber et al., possible causes of salinization have been identified: (i) saline intrusion , (ii) infiltration of brackish waters from the Kaluvelly swamp, (iii) input linked to agricultural practices, and (iv) upward migration of older more saline groundwaters in response to the hydraulic gradient. A simplified cross section of the sedimentary part is presented in Fig. 1b. ...
... To complement major elements, isotopic data on elements such as O, H, Sr, and sometimes S, are widely used to identify end-members involved in the groundwater signature (e.g. [Armstrong et al., 1998], [Gosselin et al., 2004], [Brenot et al., 2008] and [Raiber et al., 2009]). In order to identify the origin of salinity, the use of elemental and isotopic compositions of B (e.g. ...
In the multilayered aquifer of Kaluvelly (India), comprising various sedimentary layers overlying a charnockitic basement, concentrations of trace elements were measured in aquifer formations and in groundwaters to identify geochemical tracers for water bodies. The two main sandstones (Cuddalore and Vanur) originate from the charnockites and the Cuddalore sandstone has experienced lateritization. In the studied area, two charnockite end-members were identified: a dioritic and a granitic one. Mineralogical composition and whole-rock Ti concentrations confirmed the charnockite which displayed the granitic composition as the parent rock of the two sandstones. Titanium distribution indicates that the Cuddalore sandstone originates from a more intense weathering of the parent material than the Vanur sandstone. Despite extensive differences in trace element contents recorded in aquifer formations, only a few trace elements were suitable to distinguish the water bodies. Among soluble elements, Li (in the Vanur aquifer) and Ba (in the charnockite and carbonaceous aquifers) can be used as tracers. As the input of these elements in solution is mainly regulated by the available stock, for a given mineralogical origin there is a direct link between the aquifer formation composition and water signature. With the exception of As, concentrations of redox-sensitive elements were not preserved during pumping because of oxidation, preventing their use as tracers. Low-mobility elements such as La, Ce, Th, Zr, Nb, Hf, or Ta were too insoluble to be detected in waters and/or to record the aquifer formation signature. Their input in solution was not regulated by the available stock but by the dissolution rate of rock-forming minerals. Only Ti can be used to distinguish between two out of the three aquifers (charnockite and Vanur). The specific behavior of Ti recorded in these waters may be linked to rutile inclusions within plagioclases and to the influence of climate on Ti solubility.
... Now they are increasingly used to identify Ca sources due to the similar chemical behaviour of Sr and Ca (Åberg et al., 1989; Gosz and Moore, 1989; Wickman and Jacks, 1992; Miller et al., 1993; Bailey et al., 1996; Clow et al., 1997 Clow et al., ). Åberg et al. (1989, Wickman and Jacks (1992), Bain and Bacon (1994), Clow et al. (1997), Probst et al. (2000, Harrington and Herczeg (2003) studied weathering processes and Frape et al. (1984), Kay and Darbyshire (1986), Négrel et al. (2003) and Gosselin et al. (2004) water–rock interactions in watersheds using Sr isotope ratios. The impact of atmospheric inputs on water quality in watersheds was investigated by Graustein and Armstrong (1983), Gosz and Moore (1989) and Probst et al. (2000). ...
The role of different minerals in base cation release and thus the increase of buffering capacity of groundwater against acid deposition is controversially discussed in the literature. The ⁸⁷Sr/⁸⁶Sr ratios and base cation concentration were investigated in whole rock leachates, mineral separates, precipitation, soil solution, groundwater and stream water samples in the Lehstenbach catchment (Germany) to identify the weathering sequence of the granite bedrock. Three different approaches were followed in parallel. It was assumed that the contribution of different minerals to base cation supply of the groundwater with increasing weathering intensity would be observed by investigating (1) unweathered rock leachates, deep groundwater and shallow groundwater, (2) groundwater samples from new groundwater wells, reflecting the initial weathering of the drilled bedrock, and groundwater from wells that were drilled in 1988, (3) stream water during baseflow, dominated by deep groundwater, and stream water during high flow, being predominantly shallow groundwater. Whereas the first approach yielded consistent patterns, there was some evidence that groundwater from the new wells initially reflected contamination by the filter gravel rather than cation release in an initial stage of weathering. Time series samples of stream water and groundwater solute concentrations and isotope ratios turned out to reflect varying fractions of soil water and precipitation water at baseflow and high flow conditions rather than varying contributions of different minerals that prevail at different stages of granite weathering.
... Strontium (Sr) is generally used as a tracer due to its geochemical characteristics. While classified as a trace element, Sr occurs in easily detectable amounts in most rock types and behaves geochemically like Ca (Gosselin et al. 2004;Faye et al. 2005). Groundwaters acquire Sr because of their interaction with Sr-bearing minerals such as celestite (SrSO 4 ) associated with gypsum and strontianite (SrCO 3 ), carbonate and clay minerals through adsorption and ion exchange reactions accompanying calcium (Ca) ion (Morgan-Jones and Eggboro 1981). ...
In the Grombalia region, Cap Bon Peninsula, northeastern Tunisia, increasing population and development of agricultural activity
during the last few decades have engendered large expansion of groundwater pumping from the shallow, unconfined aquifer. Recently,
the water table has displayed some signs of overexploitation such as decline in the water level in boreholes and considerable
deterioration of water quality. Hydrochemical and isotopic data were used in conjunction with hydrogeological characteristics
to investigate the groundwater composition in this aquifer. It has been demonstrated that groundwaters, recharged mainly in
the surrounding foothills, acquire their mineralization principally by water–rock interaction, i.e., dissolution of evaporites
and reverse cation exchange, and secondarily by return flow of irrigation waters. The isotopic signature of groundwaters permits
identification of two different types. Water with depleted δ18O and δ2H contents is interpreted as recharge by non-evaporated rainfall, originating from a mixture of Atlantic and Mediterranean
air masses. However, water with relatively enriched δ18O and δ2H contents is thought to reflect contamination by return flow of irrigation waters. Tritium contents, ranging between 1.2
and 4.5TU indicate that groundwaters in an unconfined aquifer derive from post-nuclear recharge or contain a significant
component of post-1950s water. The recent origin of these groundwaters is confirmed by the high carbon-14 activities, exceeding
sometimes 100%, indicating the existence of a significant fraction of organic 14C. This younger source of radiocarbon is, however, highlighted by the depleted δ13C contents, corresponding to a system where CO2 of C4 plants predominates.
KeywordsUnconfined aquifer-Evaporite-Cation exchange-Return flow-Post-nuclear recharge-Organic carbon
... Although classified as a trace element, Sr occurs in easily measurable quantities in most rock types and behaves geochemical like Ca (Gosselin et al. 2004), and the aquifers have probably multiple sources of dissolved strontium. Enrichment of Sr in some waters could be related with the time of residence of water in the aquifer, so that the ion is a good environmental tracer (Brondi et al. 1983). ...
The salinization process was investigated with hydrogeochemical tools to evaluate the origin of salinity in the Selçuk Plain.
Na/Cl and Cl/Br molar ratios of coastal zone that covers an alluvial aquifer, karstic discharges, and a wetland are similar
to the local seawater ratio. According to mixing ratios, seawater addition can reach 9–18% in both seasons at the coastal
zone especially in karstic springs that are a kind of seawater–freshwater mixing points. A thematic map of the Salinization
zone was constructed for the Selçuk Plain using geographical information system tools with different parameters such as major
ion ratios, EC values, mixing ratios, and sodium adsorption ratio values. High correlation between Cl and Br, B, Li and Sr
explains the salinization process that comes from marine intrusion. The δ
18O and δD composition of water samples varies between −6.7‰ and −2.9‰; −37‰ and −20‰, respectively. The coastal zone waters are plotted
on the mixing line due to the effects of the salinization process in the plain.
... In previous studies throughout the world, strontium isotopes have been used to characterize groundwater flowpaths in often complex hydrogeological settings (e.g. Johnson and DePaolo, 1994;Harrington and Herczeg, 2003;Gosselin et al., 2004;Klaus et al., 2007;Shand et al., 2007;Uliana et al., 2007;Cartwright et al., 2007), identify mixing of water of different sources (e.g. Woods et al., 2000;Frost and Toner, 2004;Singleton et al., 2006) or investigate mineral weathering reactions (e.g. ...
To better understand the spatial distribution of groundwater salinisation in western Victoria, southeast Australia, the interactions between a surficial basalt aquifer and an underlying extensive palaeodrainage (‘deep lead’) system were studied using a multi-disciplinary approach, combining strontium isotope analyses with major ion chemistry and the interpretation of geological and hydrogeological data. The strontium isotopes proved particularly useful in delineating flow paths and hydraulic connections between the two aquifers, which have contrasting 87Sr/86Sr ratios. The freshest basalt groundwaters lie beneath volcanoes and have 87Sr/86Sr signatures close to the whole-rock strontium isotope ratios of the basalts (∼0.7045), indicating the strong influence of basalt weathering. With increasing distance from the eruption points, basalt groundwaters become progressively more saline and the strontium isotope ratios evolve towards the more radiogenic signatures of local rainfall (0.710–0.711), due to the slow addition of infiltration concentrated by evapotranspiration during its passage through the thick, clay-rich soils developed on the basalt lavas. Overall, the influence of rainwater on the strontium isotope signatures of the basalt groundwater is much greater than that of basaltic weathering, indicating that rainwater can play a greater role in determining groundwater strontium composition than is often realised. Most parts of the palaeodrainage system beneath the basalt are preferentially recharged through the volcanoes, as shown by strong downwards hydraulic gradients and groundwater 87Sr/86Sr ratios similar to the least radiogenic basalt groundwaters. However, in the northwestern part, groundwater 87Sr/86Sr ratios are closer to those of the source material of the sediments (Palaeozoic bedrock), indicating that here recharge occurs predominantly in the headwaters where the basalts are absent. In the southern and western sections of the palaeodrainage system there is an upward flux into the overlying basalts, as shown by strong upward hydraulic gradients and elevated strontium isotope signatures in basalt groundwaters. This occurs because lateral groundwater flow in the palaeodrainage system is restricted by shallow subsurface basement ridges, and ultimately discharges to the surface as salt lakes.
Strontium isotopes (87Sr/86Sr) are useful to trace processes in the Earth sciences as well as in forensic, archaeological, palaeontological, and ecological sciences. As very few large-scale Sr isoscapes exist in Australia, we have identified an opportunity to determine 87Sr/86Sr ratios on archived fluvial sediment samples from the low-density National Geochemical Survey of Australia. The present study targeted the northern parts of Western Australia, the Northern Territory, and Queensland, north of 21.5∘ S. The samples were taken mostly from a depth of ∼60–80 cm in floodplain deposits at or near the outlet of large catchments (drainage basins). A coarse (<2 mm) grain-size fraction was air-dried, sieved, milled, and digested (hydrofluoric acid + nitric acid followed by aqua regia) to release total Sr. The Sr was then separated by chromatography, and the 87Sr/86Sr ratio was determined by multicollector inductively coupled plasma mass spectrometry. The results demonstrate a wide range of Sr isotopic values (0.7048 to 1.0330) over the survey area, reflecting a large diversity of source rock lithologies, geological processes, and bedrock ages. The spatial distribution of 87Sr/86Sr shows coherent (multi-point anomalies and smooth gradients), large-scale (>100 km) patterns that appear to be broadly consistent with surface geology, regolith/soil type, and/or nearby outcropping bedrock. For instance, the extensive black clay soils of the Barkly Tableland define a >500 km long northwest–southeast-trending unradiogenic anomaly (87Sr/86Sr <0.7182). Where sedimentary carbonate or mafic/ultramafic igneous rocks dominate, low to moderate 87Sr/86Sr values are generally recorded (medians of 0.7387 and 0.7422, respectively). Conversely, In proximity to the outcropping Proterozoic metamorphic basement of the Tennant, McArthur, Murphy, and Mount Isa geological regions, radiogenic 87Sr/86Sr values (>0.7655) are observed. A potential correlation between mineralization and elevated 87Sr/86Sr values in these regions needs to be investigated in greater detail. Our results to date indicate that incorporating soil/regolith Sr isotopes in regional, exploratory geoscience investigations can help identify basement rock types under (shallow) cover, constrain surface processes (e.g. weathering and dispersion), and, potentially, recognize components of mineral systems. Furthermore, the resulting Sr isoscape and future models derived therefrom can also be utilized in forensic, archaeological, palaeontological, and ecological studies that aim to investigate, for example, past and modern animal (including humans) dietary habits and migrations. The new spatial Sr isotope dataset for the northern Australia region is publicly available (de Caritat et al., 2022a; https://doi.org/10.26186/147473).
Shallow groundwater and lake water are the dominant water resources in the Badain Jaran Desert. There are still controversial hypotheses related to the origin of groundwater in this desert. Few studies have been conducted to explore the Sr provenance of these waters and assess the water–rock interactions using a Sr isotope approach until now. In this text, the Sr isotope data of waters in the hinterland of the Badain Jaran Desert and neighbouring areas are reported. The waters in the Badain Jaran Desert have few links to its surrounding rivers, but could be influenced by the precipitation in the Yabulai Mountains. The ⁸⁷Sr/⁸⁶Sr ratio changes constantly, while the Sr²⁺ concentration of shallow groundwater gradually decreases from Yabulai to the desert hinterland to Gurinai-Guaizihu. Combined with hydrochemical data and hydrodynamic conditions, these results show that the dissolved Sr of waters in the desert hinterland is controlled by the Yabulai precipitation and catchment weathering. They further show that the desert shallow groundwater Sr originates mainly from the Yabulai precipitation (> 94 %), while whole-rock weathering contributes little (< 6 %), as calculated using isotope mass balance equations. Relative Sr contributions to lakes from shallow groundwater and catchment weathering are calculated to be 92.5 and 7.5 %, respectively.
Porewater extractions and acid leachates of rock core from a 250 m thick sequence of low-permeability Ordovician-age shales and limestones, on the eastern flank of the Michigan Basin, were analysed for strontium isotope ratios in an attempt to infer porewater ages from observed ⁸⁷ Sr/ ⁸⁶ Sr enrichments. The porewaters originated as Ordovician seawater, which subsequently mixed with evaporated Silurian seawater infiltrating from above, and, to some extent, with a deep brine—with an enriched ⁸⁷ Sr/ ⁸⁶ Sr signature—from the underlying crystalline shield or deep basin. The porewater ⁸⁷ Sr/ ⁸⁶ Sr ratios are more radiogenic than contemporaneous seawater but show no obvious correlation to those leached from the solid rock phases. Accepting that the initial ⁸⁷ Sr/ ⁸⁶ Sr signatures in porewaters were dominated by Late Silurian brine, potentially with an additional deep brine component, the excess of radiogenic ⁸⁷ Sr appears to represent ingrowth from ⁸⁷ Rb decay over a time span of some 420 million years, approaching the depositional age of the rocks. Similarly, Rb/Sr errochron ages of acid leachates of solid phases, and the calculated initial ⁸⁷ Sr/ ⁸⁶ Sr isotopic ratios, are consistent with a proposition that the calcites inherited their Sr from Ordovician seawater and were dolomitized shortly afterwards by infiltrating Mg-enriched evaporative brine, indicating long-term conservative behaviour for the enclosing carbonate rocks. The errochron for leachates from (alumino)silicates yields a high initial ⁸⁷ Sr/ ⁸⁶ Sr, but with an errochron age of about 340 ± 48 Ma, likely owing to variable admixtures of diagenetic illite in the shales. Overall, the data provide evidence for a stable hydrologic regime since Paleozoic time.
To understand the characteristics of Ca isotope composition and fractionation in silicate-dominated Quaternary aquifer system, hydrochemical and isotope studies (⁸⁷Sr/⁸⁶Sr, ¹³CDIC and 44/40Ca) were conducted on groundwater, sediment and rock samples from the Datong basin, China. Along the groundwater flow path from the basin margin to the center, groundwater hydrochemical type evolves from Ca-HCO3 to Na-HCO3/Na-Cl type, which results from aluminosilicate hydrolysis, vertical mixing, cation exchange between CaX2 and NaX, and calcite/dolomite precipitation. These processes cause the decrease in groundwater Ca concentration and the associated modest fractionation of groundwater Ca isotopes along the flowpath. The groundwater δ44/40Ca value varies from -0.11 to 0.49 ‰. The elevated δ44/40Ca ratios in shallow groundwater are attributed to vertical mixing involving addition of irrigation water, which had the average δ44/40Ca ratio of 0.595 ‰. Chemical weathering of silicate minerals and carbonate generates depleted δ44/40Ca signatures in groundwater from Heng Mountain (east area) and Huanghua Uplift (west area), respectively. Along the groundwater flow path from Heng Mountain to central area of east area, cation exchange between CaX2 and NaX on clay mineral results in the enrichment of heavier Ca isotope in groundwater. All groundwater samples are oversaturated with respect to calcite and dolomite. The groundwater environment rich in organic matter promotes the precipitation of carbonate minerals via the biodegradation of organic carbon, thereby further promoting the elevation of groundwater δ44/40Ca ratios.
Global water cycles, ecosystem assemblages and weathering rates were impacted by the ∼4°C of global warming that took place over the course of the last glacial termination. Fossil groundwaters can be useful indicators of late-Pleistocene precipitation isotope compositions, which, in turn, can help to test hypotheses about the drivers and impacts of glacial-interglacial climate changes. Here, a global catalog of 128 fossil groundwater records is used to interpolate late-Pleistocene precipitation δ18O across the global landmass. The interpolated data show that extratropical late-Pleistocene terrestrial precipitation was near uniformly depleted in 18O relative to the late Holocene. By contrast, tropical δ18O responses to deglacial warming diverged; late-Pleistocene δ18O was higher-than-modern across India and South China but lower-than-modern throughout much of northern and southern Africa. Groundwaters that recharged beneath large northern hemisphere ice sheets have different Holocene-Pleistocene δ18O relationships than paleowaters that recharged subaerially, potentially aiding reconstructions of englacial transport in paleo ice sheets. Global terrestrial late-Pleistocene precipitation δ18O maps may help to map 3D groundwater age distributions, constrain Pleistocene mammal movements, and better understand glacial climate dynamics. This article is protected by copyright. All rights reserved.
Due to the differences in the regional geological and the hydrogeological conditions and the impacts of human activities and climate changes, the process of regional groundwater geochemistry evolution is complex, and controlled by lots of factors. On the basis of the summary of the current major research achievements, this paper gives some reviews about: (1) the principles and methods of analyzing geochemistry system of groundwater; (2) the hydrogeological, isotopic, element analysis methods and applied techniques in the study of groundwater evolution; (3) the geochemical models and the well-known software of simulating groundwater evolution. And in the future, the complex action of natural evolution and human activity, the interaction of groundwater and surface water, the interaction of microbe-water-rock are the hotspots and developing tendencies. In which, the coupling of the physical, chemical and biological actions would be the significant filed in the regional groundwater evolution.
In this study, the chemical and Sr isotopic compositions of shallow groundwater and rainwater in the Ordos Desert Plateau, North China, and river water from the nearby Yellow River, are investigated to determine the dissolved Sr source and water-rock interactions, and quantify the relative Sr contribution from each end-member. Three groundwater systems have been identified, namely, GWS-1, GWS-2 and GWS-3 according to the watershed distribution in the Ordos Desert Plateau. Ca2+ and Mg2+ are the most dominant cations in GWS-1, while Na+ is dominant in GWS-3. In addition, there is more SO42- and less Cl- in GWS-1 than in GWS-3. The shallow groundwater in GWS-2 seems to be geochemically between that in GWS-1 and GWS-3. The 87Sr/86Sr ratios of the shallow groundwater are high in GWS-1 and GWS-2 and are low in GWS-3. By geochemically comparing the nearby Yellow River, local precipitation and deep groundwater, the shallow groundwater is recharged only by local precipitation. The ionic and isotopic ratios indicate that carbonate dissolution is an important process controlling the chemistry of the shallow groundwater. The intensity of the water-rock interactions varies among the three groundwater systems and even within each groundwater system. Three end-members controlling the groundwater chemistry are isotopically identified: (1) precipitation infiltration, (2) carbonate dissolution and (3) silicate weathering. The relative Sr contributions of the three end-members show that precipitation infiltration and carbonate dissolution are the primary sources of the shallow groundwater Sr in GWS-3 whereas only carbonate dissolution is responsible for the shallow groundwater Sr in GWS-1 and GWS-2. Silicate weathering seems insignificant towards the shallow groundwater's chemistry in the Ordos Desert Plateau. This study is helpful for understanding groundwater chemistry and managing water resources.
We present new 87Sr/ 86Sr ratios in groundwater from Proterozoic and Cambrian sandstone aquifers of southeastern Minnesota (USA), emphasizing the Mt. Simon aquifer. In Mt. Simon waters, 87Sr/ 86Sr ranges from 0.7141 in the recharge area to 0.7085 at depth. Sampling of the overlying Franconia, Ironton, and Galesville aquifers similarly indicates 87Sr/ 86Sr from 0.7132 in shallow conditions to 0.7086 at depth. Proterozoic sandstone aquifers in shallow bedrock conditions exhibit 87Sr/ 86Sr of 0.7103-0.7119. Sr sources to the Mt. Simon include: (1) more radiogenic Sr derived from overlying Cretaceous rocks and/or Pleistocene glacial deposits that incorporate Precambrian crystalline rocks and Cretaceous sedimentary rocks; and (2) less radiogenic Sr associated with Na-bearing waters, possibly from plagioclase weathering. Overall, the observed 87Sr/ 86Sr and correlation with carbon-14 activity record the Sr system's sensitivity to groundwater evolution from the recharge area to deep, slow-circulating areas and contributions from multiple Sr sources associated with hydrogeologic setting.
The Dongrae thermal water area located at the southeastern marginal part of the Korean Peninsula is one of the oldest hot springs in Korea. The Dongrae thermal water shows Na-Cl type of water chemistry, whereas the shallow cold groundwater is Ca(-Na)- type. In this paper, we discuss the age of the Dongrae hot spring, i.e. groundwater cycle among meteoric water-surface water-shallow groundwater-hot spring water. The ratios of the thermal water in Dongrae area range from 0.705663 to 0.705688 and are lower than those of groundwater, surface water and rain water as well as aquifer bearing granite. These Sr isotopic signatures in the Dongrae thermal water indicate that the circulation rate between thermal water and current meteoric water including groundwater, surface water and rain water in the Dongrae area should be very slow. The age of the Dongrae hot spring water range from BP(before present) to BP whereas that of the shallow groundwater is BP. This suggests that the period of groundwater cycle among meteoric water, surface water, shallow groundwater and hot spring should be more than 1,270 years. Then, it also indicates that the present Dongrae hot spring may be a mixed water between the old thermal water heated for at least 1,270 years and the present shallow cold groundwater.
A batch experiment was carried out to investigate a variation of Sr concentration and ratio in the solution by water-rock interaction. The experiments were conducted at room temperature using two kinds of granites (biotite granite and garnet-bearing granite), de-ionized water. surface water. Water/rock ratio was 1:1. For comparison, we also performed another experiment under water/rock condition of 10:1. Then, the concentration of the cations and anions in the solutions showed severe variation during water/rock interaction. However, after sometime, the ratio of the solution moved to the ratio of the rocks and showed relatively constant value. This suggests that the ratio between water and rock becomes to be stable faster than the elemental equilibration of the element in the solution, and is not affected by interaction condition. Therefore, ratio of the groundwater may be useful in calculating the mixing ratio between different aquifer.
The Seokmodo consists mainly of biotite granite and granodiorite. The biotite granite is divided into the south and the north part by granodiorite. There occurs high temperature hot spring of which temperature is up to . The Rb-Sr isotopic data for the biotite granite define whole-rock isochron ages of Ma with initial Sr isotopic ratio of 0.7132 in north part and Ma with initial Sr isotopic ratio of 0.7125 in south part, suggesting that the magma be derived from the crustal source material. The geochemical characteristics of the biotite granite and hornblende granodiorite indicate that they were crystallized from calc-alkaline under syn-collisional tectonic environment. The samples of hot spring were collected at March 2005 and March 2006. The ratios of hot spring are 0.714507 and 0.714518, respectively and correspond to those oi the granite being occurred at the south part. The similarity of ratios between the granite and hot spring strongly suggests that the hot spring might be derived from the Seokmodo biotite granite.
Gafsa region is one of the most productive artesian basins in Southern Tunisia. It is located in the southwestern part of the country, and its groundwater resources are developed for water supply and irrigation. Proper understanding of the geochemical evolution of groundwater is important for sustainable development of water resources in this region. A hydrogeochemical survey was conducted on the Plio-Quaternary shallow and on the Complex Terminal aquifers system using major (Ca, Mg, Na, SO4, Cl, NO3 and HCO3) and minor (Sr) elements, in order to evaluate the groundwater chemistry patterns and the main mineralization processes occurring in this system. Hydrochemical and isotopic data were used in conjunction with hydrogeological characteristics to investigate the groundwater composition in these aquifers. It has been demonstrated that groundwaters acquire their mineralization principally by water–rock interaction, i.e. dissolution of evaporites (halite/gypsum, pyrite, etc.) and return flow of irrigation waters, and by anthropogenic activities due to the use of nitrogen (N) fertilizers–pesticides in agriculture. The isotopic study of “stable isotopes, radiocarbon and tritium” (Yermani 2002) shows that a paleoclimatic recharge is corroborated by the relatively low carbon-14 activities (5–25.3%) of the referred groundwater group samples, which were interpreted as recharge occurring during the late Pleistocene and the early Holocene periods. The water feedings of these aquifers are mainly provided by infiltration of precipitations, infiltration of irrigation water, lateral feeding from Cretaceous relieves from the South and the North and along recent and fossil drainage networks that constitute major freshwater sources in groundwater tables (Hamed et al., J Environ Protect 1:466–474, 2010a).
Highlights
► We delineate the flow paths in high arsenic groundwater aquifer system. ► We model the evolution of chemical and Sr isotopic composition along the flow paths. ► Groundwater flow regime has effect on arsenic enrichment in groundwater.
Submarine groundwater discharge (SGD) to the ocean supplies Sr with less radiogenic 87Sr/86Sr than seawater, and thus constitutes an important term in the Sr isotope budget of the modern ocean. However, few data exist for Sr in coastal groundwater or in the geochemically dynamic subterranean estuary (STE). We examined Sr concentrations and isotope ratios from nine globally-distributed coastal sites and characterized the behavior of Sr in the STE. Dissolved Sr generally mixed conservatively in the STE, although large differences were observed in the meteoric groundwater end-member Sr concentrations among sites (0.1–24 μM Sr). Strontium isotope exchange was observed in the STE at five of the sites studied, and invariably favored the meteoric groundwater end-member signature. Most of the observed isotope exchange occurred in the salinity range 5–15, and reached up to 40% exchange at salinity 10. Differences in fresh groundwater Sr concentrations and isotope ratios (87Sr/86Sr = 0.707–0.710) reflected aquifer lithology. The SGD end-member 87Sr/86Sr must be lower than modern seawater (i.e., less than 0.70916) in part because groundwater Sr concentrations are orders of magnitude higher in less-radiogenic carbonate and volcanic island aquifers. A simple lithological model and groundwater Sr data compiled from the literature were used to estimate a global average groundwater end-member of 2.9 μM Sr with 87Sr/86Sr = 0.7089. This represents a meteoric-SGD-driven Sr input to the ocean of 0.7–2.8 × 1010 mol Sr y−1. Meteoric SGD therefore accounts for 2–8% of the oceanic Sr isotope budget, comparable to other known source terms, but is insufficient to balance the remainder of the budget. Using reported estimates for brackish SGD, the estimated volume discharge at salinity 10 (7–11 × 1015 L y−1) was used to evaluate the impact of isotope exchange in the STE on the brackish SGD Sr flux. A moderate estimate of 25% isotope exchange in the STE gives an SGD Sr end-member 87Sr/86Sr of 0.7091. The brackish SGD Sr flux thus accounts for 11–23% of the marine Sr isotope budget, but does not appear sufficient to balance the ∼40% remaining after other known sources are included. Substantial uncertainties remain for estimating the SGD source of Sr to the global ocean, especially in the determination of the volume flux of meteoric SGD, and in the paucity of measurements of groundwater Sr isotope composition in major SGD regions such as Papua New Guinea, the South America west coast, and West Africa. Consequently, our global estimate should be viewed with some caution. Nevertheless, we show that the combined sources of meteoric SGD and brackish SGD coupled with isotope exchange in the STE may constitute a substantial component (∼13–30%) of the modern oceanic 87Sr/86Sr budget, likely exceeding less radiogenic Sr inputs by sedimentary diagenesis and hydrothermal circulation through the mid-ocean ridge system. Temporal variation in SGD Sr fluxes and isotope composition may have contributed to fluctuations in the oceanic 87Sr/86Sr ratio over geologic time.
The Nandong Underground River System (NURS) is located in a typical karst area dominated by agriculture in SE Yunnan Province, China. Groundwater plays an important role in the social and economical development in the area. The effects of human activities (agriculture and sewage effluents) on the Sr isotope geochemistry were investigated in the NURS. Seventy-two representative groundwater samples, which were collected from different aquifers (calcite and dolomite), under varying land-use types, both in summer and winter, showed significant spatial differences and slight seasonal variations in Sr concentrations and 87Sr/86Sr ratios. Agricultural fertilizers and sewage effluents significantly modified the natural 87Sr/86Sr ratios signature of groundwater that was otherwise dominated by water–rock interaction. Three major sources of Sr could be distinguished by 87Sr/86Sr ratios and Sr concentrations in karst groundwater. Two sources of Sr are the Triassic calcite and dolomite aquifers, where waters have low Sr concentrations (0.1–0.2mg/L) and low 87Sr/86Sr ratios (0.7075–0.7080 and 0.7080–0.7100, respectively); the third source is anthropogenic Sr from agricultural fertilizers and sewage effluents with waters affected having radiogenic 87Sr/86Sr ratios (0.7080–0.8352 for agricultural fertilizers and 0.7080–0.7200 for sewage effluents, respectively), with higher Sr concentrations (0.24–0.51mg/L). Due to the overlapping 87Sr/86Sr ratios, it is difficult to distinguish the sources of Sr in groundwater samples contaminated by agricultural fertilizers or sewage effluents based only on their 87Sr/86Sr ratios. However, 87Sr/86Sr ratios do provide key information for natural and anthropogenic sources in karst groundwater.
We examined the origin of the U-enriched groundwater in Daejeon, near the Ogcheon U zone in Korea. For this study, groundwater ionic species and C, S, and Sr isotopic compositions were analyzed. The U-enriched groundwater occurred only in the Daejeon granite region, while all the groundwater in the Ogcheon Supergroup showed very low U concentrations. In the granite region, the pedospheric or atmospheric origin of dissolved C and S means that the aquifer has been well connected to the oxidized surface environment. The Sr/Sr ratios indicated a lithospheric origin of Sr. Groundwater isotopic compositions in the Ogcheon belt varied greatly, indicating their complex sources. In this region, dissolved C originated from graphite-rich slate and limestone. The broad range of δS suggested that the composite sources included atmospheric SO for most groundwater, lithogenic SO for mine drainage and quarry water, and anthropogenic SO for polluted groundwater. This study indicates that the U-enriched groundwater is not related to the present U ores in the Ogcheon belt but is genetically associated with the granite body itself. The varying but considerable U contents within the granite body can be present as isolated groups. We infer that locally high U contents in the Daejeon granite might inherently be due to assimilation of the Ogcheon U-mineralized zone into granitic melt during the Mesozoic; however, the pH and Eh conditions except aquifer geology were very important factors in developing highly enriched U groundwater in the Daejeon granite region. Thermodynamic modeling highlights the importance of dissolved Ca and (bi-)carbonate in U geochemistry.
An extensive suite of isotopic and geochemical tracers in groundwater has been used to provide hydrologic assessments of the hierarchy of flow systems in aquifers underlying the central Great Plains (southeastern Colorado and western Kansas) of the United States and to determine the late Pleistocene and Holocene paleotemperature and paleorecharge record. Hydrogeologic and geochemical tracer data permit classification of the samples into late Holocene, late Pleistocene–early Holocene, and much older Pleistocene groups. Paleorecharge rates calculated from the Cl concentration in the samples show that recharge rates were at least twice the late Holocene rate during late Pleistocene–early Holocene time, which is consistent with their relative depletion in 16O and D. Noble gas (Ne, Ar, Kr, Xe) temperature calculations confirm that these older samples represent a recharge environment approximately 5°C cooler than late Holocene values. These results are consistent with the global climate models that show a trend toward a warmer, more arid climate during the Holocene.
An integrated geochemical-sedimentological project is studying the paleoclimatic and paleogeographic characteristics of the mid Cretaceous greenhouse world of western North America, A critical part of this project, required to establish a temporal framework, is a stratigraphic study of depositional relationships between the Albian-Cenomanian Dakota and the Upper Albian Kiowa formations of the eastern margin of the Western Interior Seaway (WIS), Palynostratigraphic and sedimentologic analyses pro,ide criteria for the Dakota Formation to be divided into three sedimentary sequences bounded by unconformities (D-0, D-1, and D-2) that are recognized from western Iowa to westernmost Kansas. The lowest of these sequences, defined by unconformities D-0 and D-1, is entirely Upper Albian, and includes the largely nonmarine basal Dakota (lower part of the Nishnabotna Member) strata in western Iowa and eastern Nebraska and the marine Kiowa Formation to the southwest in Kansas. The gravel-rich fluvial deposits of the basal part of the Nishnabotna Member of the Dakota Formation correlate with transgressive marine shales of the Kiowa Formation. This is a critical relationship to establish because of the need to correlate between marine and nonmarine strata that contain both geochronologic and paleoclimatic proxy data. The basal gravel facies (up to 40 m thick in western Iowa) aggraded in incised valleys during the Late Albian Kiowa-Skull Creek marine transgression. In southeastern Nebraska, basal gravels intertongue with carbonaceous mudrocks that contain diverse assemblages of Late Albian palynomorphs, including marine dinoflagellates and acritarchs, This palynomorph assemblage is characterized by occurrences of palynomorph taxa not known to range above the Albian Kiowa-Skull Creek depositional cycle elsewhere in the Western Interior, and correlates to the lowest of four generalized palynostratographic units that are comparable to other palynological sequences elsewhere in North America. Tidal rhythmites in mudrocks at the Ash Grove Cement Quarry in Louisville (Cass County), Nebraska record well-developed diurnal and semimonthly tidal cycles, and moderately well developed semiannual cycles. These tidal rhythmites are interpreted to have accumulated during rising sea level at the head of a paleoestuary that experienced at least occasional mesotidal conditions. This scenario places the gravel-bearing lower part of the Nishnabotna Member of the Dakota Formation in the mouth of an incised valley of an Upper Albian transgressive systems tract deposited along a tidally influenced coast. Furthermore, it provides a depositional setting consistent with the biostratigraphic correlation of the lower part of the Nishnabotna Member of the Dakota Formation to the marine Kiowa Formation of Kansas.
Sensitivity analysis of a steady-state vertical profile flow model demonstrates that the flow system in the upper Dakota in western Kansas is heavily influenced by the Upper Cretaceous aquitard, the Arkansas River in southeastern Colorado, and rivers in central Kansas, such as the Saline, that have eroded through the aquitard and into the Dakota to the west of the main outcrop area of the aquifer. The model shows that local flow systems and the vertical hydraulic conductivity of the Upper Cretaceous aquitard heavily influence the water budget and the flow patterns. The aquitard restricts recharge from the overlying water table to underlying aquifers in western Kansas because of its considerable thickness and low vertical hydraulic conductivity. The Arkansas River intercepts ground-water flow moving toward western Kansas from recharge areas south of the river and further isolates the upper Dakota from sources of freshwater recharge. In central Kansas, the Saline River has reduced the distance between confined portions of the aquifer and its discharge area. In essence, this has improved the hydraulic connection between the confined aquifer and its discharge area, thus helping to generate subhydrostatic conditions in the upper Dakota upgradient of the river. -Author
The 87Sr/86Sr ratio has been extensively used in groundwater studies for several reasons. While classified geochemically as a trace element, Sr is found in easily measurable quantities in a wide variety of rocks. It is soluble in aqueous solution as the +2 ion and is geochemically very similar to Ca, the latter a major alkaline-earth constituent of rocks. The half-life of 87Rb, which decays to 87Sr, is such that considerable variations exist in the present-day 87Sr/86Sr ratio in minerals. Finally, Sr isotopes are not measurably fractionated by geological processes, unlike the isotopes of the light elements. All these characteristics potentially make Sr a good tracer of the source rock(s) of the chemical constituents in water. The isotopic value provides an added insight to that achieved by analysing elemental abundances, and this is especially the case when there is precipitation of new mineral phases because this process changes the chemistry of the water, but not the isotopic composition.
The historic type area of the Dakota Formation lies along the Missouri and Big Sioux River Valleys in northeast Nebraska and northwest Iowa, in the eastern margin area of the Western Interior Province. The type Dakota sequence is characterized to provide a basis of comparison with supposed "Dakota' sections elsewhere in the Western Interior. The general sequence includes: 1) a lower sandstone-dominated Nishnabotna Member with coarse-grained and conglomeratic facies, and 2) an upper mudstone-dominated Woodbury Member with sandstone channel bodies and lignites. The depositional sequence is described. The Woodbury Member is of Cenomanian age, and is interpreted to have aggraded in response to sea-level rise in the adjacent seaway during transgressive phases of the Greenhorn Cyclothem, with progressive eastward displacement of nonmarine by marine facies. The age of the lower Dakota sequence is known with less certainty, but is probably upper Albian in part. -from Authors
Substantial flowpath-related variability of 87Sr/86Sr is observed in groundwaters collected from the Trout Lake watershed of northern Wisconsin. In the extensive shallow aquifer composed of sandy glacial outwash, groundwater is recharged either by seepage from lakes or by precipitation that infiltrates the inter-lake uplands. 87Sr/86Sr of groundwater derived mainly as seepage from a precipitation-dominated lake near the head of the watershed decreases with progressive water chemical evolution along its flowpath due primarily to enhanced dissolution of relatively unradiogenic plagioclase. In contrast, 87Sr/86Sr of groundwater derived mainly from precipitation that infiltrates upland areas is substantially greater than that of precipitation collected from the watershed, due to suppression of plagioclase dissolution together with preferential leaching of Sr from radiogenic phases such as K-feldspar and biotite.
Anomalously low fluid potential (and hence subnormal fluid pressure) is found in Mesozoic and Paleozoic rocks of the Denver basin. The potentiometric surface for the Dakota and basal Cretaceous sandstones is 2000-3000 ft (600-900 m) beneath the land surface in parts of the Denver basin in Colorado and Nebraska. The potentiometric surface for pre-Pennsylvanian carbonate rocks is 1500 ft (450 m) lower than the potentiometric surface for the Dakota Sandstone in southeastern Colorado and western Kansas. The low fluid potential seems especially anomalous considering the high elevation of the outcrops along the Laramie and Front Ranges and the Black Hills. A quasi-three-dimensional numerical flow model is used to investigate the regional flow system in the Denver basin and adjacent Mid-Continent. The model simulates flow through the entire Phanerozoic sedimentary column and indicates that subnormal pressures are a consequence of hydraulic insulation of the strata within the basin from their recharge zones as compared to their discharge zones. 22 figures, 3 tables.
Sr isotope data on groundwater samples from coal and overlying sandstone aquifers in the eastern Powder River Basin, Wyoming, demonstrate that the Sr isotope ratio effectively identifies groundwater from different aquifers where major ion geochemistry and O and H stable isotope data fail. Groundwaters from sandstone aquifers have a uniform 87Sr/86Sr ratio of 0.7126 0.7127. Waters from coal seams vary from 87Sr/86Sr ratio = 0.7127 near the recharge area to 0.7151 farther into the basin. The distinct Sr isotope signatures of sandstone and coal aquifers may reflect different sources of Sr in these two rock types: Sr in sandstones is held primarily in carbonate cement, whereas coals contain more radiogenic Sr in organic matter. The Sr isotope ratio is useful in identifying wells that contain mixed waters, whether due to well construction or to incomplete aquifer isolation. Measurement and continued monitoring of the Sr isotope ratio in groundwaters should provide a powerful tool for characterizing the impact of the burgeoning coal-bed methane industry on the hydrology of the Powder River Basin.
A model enabling extraction of hydrologic information from spatial and temporal patterns in measurements of isotope ratios in water-rock systems is presented. The model describes the evolution of isotope ratios in response to solute transport and water-rock interaction. In advective systems, a single dimensionless parameter (a Damköhler number, ND) dominates in determining the distance over which isotopic equilibrium between the water and rock is approached. Some isotope ratios act as conservative tracers (ND1). If ND is close to one (i.e., the distance for equilibrium is close to the length scale of observation), isotope ratio measurements can be used to determine ND, which in turn may yield information concerning reaction rates, or spatial variations in water velocity. Zones of high velocity (e.g., as a result of greater fracture density), or less reactive zones, may be identified through observation of their lower ND values. The model is applied to paleohydrologic interpretations of Sr isotope data from calcite fracture fillings in drill cores from Yucca Mountain, Nevada (Marshall et al., 1992). The results agree with other studies suggesting ``fast path'' transport in the unsaturated zone. Also, we find that the data do not give a conclusive indication of paleowater table elevation because of the effects of water-rock interaction.
Precise measurements of 786 marine carbonate, evaporite, and phosphate
samples of known age provide a curve of seawater
87Sr/86Sr versus geologic time through the
Phanerozoic. Many episodes of increasing and decreasing values of
87Sr/86Sr of seawater have occurred through the
Phanerozoic. The Late Cambrian Early Ordovician seawater ratios are
approximately equal to the modern ratio of 0.70907. The lowest ratios,
˜0.7068, occurred during the Jurassic and Late Permian. The
configuration of the curve appears to be strongly influenced by the
history of both plate interactions and seafloor spreading throughout the
Phanerozoic. The curve provides a basis for dating many marine
carbonate, evaporite, and phosphate samples. Furthermore, diagenetic
modifications of original marine 87Sr/86Sr values
are often interpretable. Analysis of 87Sr/86Sr
data, therefore, may provide useful information on regional diagenetic
patterns and processes. All of the Cenozoic samples and some of the
Cretaceous samples are from Deep Sea Drilling Project (DSDP) cores. With
the exception of the DSDP samples, the curve was constructed only from
samples containing at least 200 ppm Sr and not more than 10% dilute acid
insoluble material. All measurements are made by comparison with
standard SrCO3 (NBS SRM 987) for which a
87Sr/86Sr of 0.71014 is assumed. Precision is
estimated to be ± 0.00005 at the 95% confidence level. Measured
ratios of 42 modern marine samples average 0.70907, with a standard
deviation of 0.00004. *Present addresses: (Denison) Suite 616, One
Energy Square. 4925 Greenville Avenue, Dallas, Texas 75206; (Nelson)
2516 West Five Mile Parkway, Dallas, Texas 75233
The 87Sr/86Sr ratios of formation waters from the chalk of the Ekofisk oilfield were measured using a new technique: extracting salt residues from the interstices of core samples. In the Danian Ekofisk Formation, the chalk matrix itself has 87Sr/86Sr and δ 13C values characteristic of Danian seawater, even though δ18O data indicate the presence of varying quantities of diagenetic carbonate cement. In the Ekofisk Formation, porewater 87Sr/86Sr values are very constant (range: 0.70786-0.70810). The formation water probably contains locally derived Sr from carbonate, plus a small contribution from noncarbonate minerals with higher 87Sr/86Sr. In the underlying Tor Formation, chalk samples containing a mixture of primary chalk and later cement, have 87Sr/86Sr values that rise with depth to a maximum of 0.70865, much higher than contemporaneous seawater. Porewater 87Sr/86Sr values increase even more dramatically with depth to a maximum of 0.70988. Both cement and waters have been influenced by Sr with a high 87Sr/86Sr probably derived from underlying sedimentary rocks. Comparison with waters brought to the surface together with produced oil indicates that the depthwise increase in 87Sr/86Sr reflects an increase in salinity from ∼50,000to∼140,000 mg/l total solute content. This suggests that Zechstein evaporites may be the source of the radiogenic Sr in the Tor Formation. The difference in isotope composition between carbonates and waters in the Ekofisk and Tor Formations indicates that their hydrochemical systems have evolved differently during diagenesis. This is due to the barrier effect of the Ekofisk Tight Zone, a hardground at the base of the Ekofisk Formation which effectively splits the reservoir vertically into two.
An analytical procedure involving sequential chemical extractions has been developed for the partitioning of particulate trace metals (Cd, Co, Cu, Nl, Pb, Zn, Fe, and Mn) into five fractions: exchangeable, bound to carbonates, bound to Fe-Mn oxides, bound to organic matter, and residual. Experimental results obtained on replicate samples of fluvial bottom sediments demonstrate that the relative standard deviation of the sequential extraction procedure is generally better than ± 10%. The accuracy, evaluated by comparing total trace metal concentrations with the sum of the five individual fractions, proved to be satisfactory. Complementary measurements were performed on the individual leachates, and on the residual sediments following each extraction, to evaluate the selectivity of the various reagents toward specific geochemical phases. An application of the proposed method to river sediments is described, and the resulting trace metal speciation is discussed.
The Dakota aquifer, composed of the Dakota Sandstone and stratigraphically equivalent sandstone units of Cretaceous age, is the upper-most regional aquifer underlying the extensively developed High Plains aquifer of the midwestern United States. The concentration of dissolved solids in ground water of the Dakota aquifer ranges from less than 500 milligrams per liter in calcium bicarbonate type water in the eastern outcrop area to more than 100,000 milligrams per liter in sodium chloride type oilfield brine in the Denver Basin to the west. Preliminary maps showing the distribution of dissolved solids confirm the complex nature of the Dakota aquifer as inferred from stratigraphic and hydraulic evidence. Extensive vertical leakage through confining layers, local recharge at the truncated eastern boundary, and a barrier to recharge along the western edge of the Denver Basin are consistent with the distribution of hydraulic head and dissolved solids.
In 1905, N. H. Darton described the geology and underground-water resources of the central Great Plains in his classic report that emphasized the importance of the Dakota aquifer to this region of the United States. Since Darton's work, many investigators have studied Dakota-aquifer hydrology with regard to development of local or statewide resources. Preliminary mapping of relatively recent fluid-level data by the U.S. Geological Survey indicates regional potentiometric trends similar to those interpreted by Darton, but altitudes substantially lower in part of the area. The classic artesian-system concept of the Dakota aquifer is not consistent with some of the data and observations of the past several decades. The simple aquifer geometry and effective lateral hydraulic continuity normally associated with that concept do not appear to characterize the Dakota aquifer regionally.
The Great Plains (Dakota) aquifer system is one of the most extensive in North America extending from the Arctic Circle to New Mexico, and underlies approximately 94% of Nebraska. In Nebraska, we do not have the physical ground water monitoring data at the scale that is necessary to manage ground water flow systems. However, first-order management strategies for this regional aquifer can be developed by understanding the geochemical evolution of the ground water. Using major-ion water chemistry data from 203 wells in 19 counties in eastern Nebraska, reconnaissance δ180, δD, and δ87Sr data, and two geochemical models, PHREEQC and SNORM, we determine that modern meteoric water, NaCl brines from underlying formations, and cold glacial melt water are the primary sources for the water in the Dakota Aquifer. Based on these three water sources and the geochemical evolution of the various water types, the following first-order management strategies are suggested. In areas where CaSO4 and Ca-Na SO4 type water occur, Pleistocene-age glacial meltwater is the source. This water supply is not easily renewable. It is recommended that detailed water resource evaluation be conducted before extensive development occurs. The source of Ca (± Mg) HCO3 type water is from recharge by local precipitation and should be managed to maintain them as a renewable resource. In mixed ground water type areas, the ground water chemistry reflects the interaction of two distinct water types, one of which is meteoric water and the other is either CaSO4 and Ca-Na SO4-type water or NaCl-type water. If the relatively fresh ground water is extracted at a rate that changes the location of the interface between the endmembers, then monitoring changes in water chemistry in a well over time could be used as an early warning system for the onset of potential problems related to overpumping.
A suite of chemical and isotope tracers (dissolved noble gases, stable isotopes of water, radiocarbon, and Cl) have been analyzed along a flow path in the Dakota aquifer system to determine likely recharge sources, ground water residence times, and the extent of mixing between local and intermediate flow systems, presumably caused by large well screens. Three water types were distinguished with the tracers, each having a very different history. Two of the water types were found in south-eastern Colorado where the Dakota is poorly confined. The tracer data suggest that the first group recharged locally during the last few thousand years and the second group was composed of ground water that recharged earlier during a cooler climate, presumably during the last glacial period (LGP) and mixed aged water. The paleotemperature record archived in this groundwater system indicates that south-eastern Colorado was about 5°C cooler during the LGP than during the late Holocene. Similar temperature changes derived from dissolved noble gases in other aquifer systems have been reported earlier for the south-western United States. The third water type was located down gradient of the first two in the confined Dakota in western and central Kansas. Groundwater residence time of this water mass is on the order of 104–105 yrs and its recharge location is near the Colorado and Kansas border down gradient of the other water types. The study shows the importance of using multiple tracers when investigating ground water systems.
The paper presents the isotopic (B, Sr, O, H) and chemical composition of solid salts, brines, groundwater, and surface water in the vicinity of a Permian salt dome in Northern Germany (diapir of Gorleben-Rambow) being considered for disposal of high level radioactive waste. The site is situated in the NW European Basin that is dominated by intensive diapirism of Permian salt and overprinted by glacial erosion/sedimentation. The local hydrogeology comprises an upper aquifer system of heterogeneous Pleistocene sediments and a lower aquifer system of Tertiary clastics tectonically disturbed by diapirism. There is a clear chemical and isotopic evolution with TDS, that generally increases with depth up to 328 g · l−1. The chemistry and isotope ratios of the saline groundwater can be explained by a two end-member mixing system. The Na-Cl brine end-member is derived from evaporite dissolution as indicated by major ion chemistry, Cl/Br ratios, Sr and B isotopes. It is mixed with fresh-brackish groundwater dominated by water-silicate interaction. This low salinity end-member (TDS from 0.3–10 g · l−1) shows radiogenic 87Sr/86Sr ratios ranging from 0.70910 to 0.71030 and low δ11B values between 7.4 and 16.5‰ vs. NBS951. Two halite samples and a borate sample from the unaltered parts of the diapir show 87Sr/86Sr ratios from 0.70696 to 0.70868 and δ11B values of 20.8 and 27.7‰. Brine (TDS from 100–328 g/l) Sr isotope ratios, ranging from 0.70758 to 0.70788, lie in the uppermost range of late Permian ocean waters and are within the range of halite. The δ11B values of the brines vary between 25.1‰ to 33.5‰, which is close to the range of solid salt but well below those of evaporating present-day sea water. B isotope composition is thus compatible with salt dissolution rather than with residual evaporite brines. The chemistry and isotope characteristics of the brine end-member derived from halite dissolution are not significantly modified by subsequent interaction with the siliciclastic aquifer material. Most highly saline groundwaters show cold climate O and H isotopic signatures with δ18O values ranging from −10.5 to −9‰. A limited group of four rather deep-seated brines (>200 m) plots in the range of Holocene signatures with δ18O > −9‰ close to those of the shallow groundwater which is interpreted as an indication of rapid groundwater circulation from the surface and ongoing salt dissolution.
Thesis (Ph. D.)--University of Kansas, Civil Engineering, 1993. Includes bibliographical references (leaves 143-153).
To assess the response of forests to a changing chemical environment, a
means is needed for separating the total cation export from the
watershed into a component derived from mineral weathering reactions and
a component due to the removal of exchangeable (plant-available) cations
in the soil1-3. We show that this separation may be possible
by using 87Sr/86Sr ratios as a tracer of cation
sources in stream water. Our measurements from a high-elevation forest
ecosystem in the Adirondack mountains, New York, indicate that mineral
weathering reactions contribute about 70% and soil cation-exchange
reactions about 30% of annual strontium exports. Based on these results
and the ratios of major cations to strontium in the local glacial till,
we estimate the release of Ca2+, Mg2+,
K+ and Na+ owing to weathering. The present
weathering rate seems adequate to replace annual losses of cations from
the total soil exchangeable pool, suggesting that the watershed is not
in immediate danger of acidification from atmospheric deposition. But as
our strontium isotope data indicate that 50-60% of the strontium in the
organic-soil-horizon exchangeable and vegetation cation pools has an
atmospheric origin, reduction of atmospheric cation inputs4
coupled with continued strong-acid anion inputs5 may result
in significant depletion of this cation reservoir.
Region 13, Western Glaciated Plains
- D H Lennox
- H Maathuis
- D Pederson
Lennox, D.H., Maathuis, H., Pederson, D., 1988. Region 13,
Western Glaciated Plains. In: Back, W., Rosenshein, J.S.,
Seaber, P.R. (Eds.), Hydrogeology. Geol. Soc. Am., The
Geology of North America, V. O-2, Boulder CO, pp. 115-128.
Regional aquifers in Kansas
- D G Jorgenson
- J O Helgeson
- J L Imes
Jorgenson, D.G., Helgeson, J.O., Imes, J.L., 1993. Regional
aquifers in Kansas, Nebraska, and Parts of Arkansas,
Colorado, Missouri, New Mexico, Oklahoma, South
Dakota, Texas, Wyoming-Geohydrologic Framework.
USGS Prof. Pap. 1414-B.
Hydrogeology of Saline Wetlands in Eastern Nebraska
- F E Harvey
- J F Ayers
- Gosselin
Harvey, F.E., Ayers, J.F., Gosselin, D.C., LaGrange, T.,
Stutheit, R., 1997. Hydrogeology of Saline Wetlands in
Eastern Nebraska. US Environmental Protection Agency,
Assistance ID No. Â997452-01-0.
Sr isotopic identification of water-rock interaction and groundwater mixing in carbonate and carbonate-cemented aquifers: examples from the Laramie and Bighorn Basins
- C D Frost
- R N Toner
Frost, C.D., Toner, R.N. Sr isotopic identification of waterrock interaction and groundwater mixing in carbonate and
carbonate-cemented aquifers: examples from the Laramie
and Bighorn Basins, Wyoming. Ground Water (in press).
Geology of the Northern Denver Basin and Adjacent Uplifts. Rocky Mountain Association of Geologists Guidebook
- J D Haun
Haun, J.D., 1963. Stratigraphy of Dakota Group and relationship to petroleum occurrence, northern Denver basin. In:
Katich, P.J., Bolyard, D.W., (Eds.) Geology of the Northern
Denver Basin and Adjacent Uplifts. Rocky Mountain Association of Geologists Guidebook, pp. 113-134.
Application of strontium and other radiogenic tracer isotopes to paleohydrologic Upham, W. 1895. The Glacial Lake Agassiz: USGS Mono-graph 25
- Z E Peterman
- J S Stuckless
Peterman, Z.E., Stuckless, J.S., 1992. Application of strontium and other radiogenic tracer isotopes to paleohydrologic Upham, W. 1895. The Glacial Lake Agassiz: USGS Mono-graph 25.
Aquifer Systems Underlying Kansas, Nebraska, and Parts of Arkansas
- J O Helgeson
- R B Leonard
- R J Wolf
Helgeson, J.O., Leonard, R.B., and Wolf, R.J., 1993. Aquifer
Systems Underlying Kansas, Nebraska, and Parts of
Arkansas, Colorado, Missouri, New Mexico, Oklahoma,
South Dakota, Texas, and Wyoming-Hydrology of the
Great Plains Aquifer System in Nebraska, Colorado, Kansas,
and Adjacent Areas. US Geol. Surv. Prof. Pap. 1414-E.
Deep Wells at Lincoln, Nebraska. Nebraska Geological Survey Paper 15. Conservation and Survey Division
- G E Condra
- E C Reed
Condra, G.E., Reed, E.C., 1939. Deep Wells at Lincoln,
Nebraska. Nebraska Geological Survey Paper 15. Conservation and Survey Division, University of Nebraska.
Halogen geochemistry of Cretaceous sandstone aquifers of North America
- Whittemore
Whittemore, D.O., Fabryka-Martin, J., 1992. Halogen
geochemistry of Cretaceous sandstone aquifers of North
America. In: Kharaka, Y.K., Maest, A.S. (Eds.), Proceedings of the 7th International Symposium on Water-Rock Interaction. A.A Balkema, Rotterdam, Netherlands,
pp. 855-858.
Geohydrology of the Dakota aquifer
- D G Jorgenson
- D C Signor
Jorgenson, D.G., Signor, D.C., 1984. Geohydrology of the
Dakota aquifer, Proceedings, First C.V. Theis Conference on
Geohydrology. National Water Well Association, Dublin OH.
Isotopic Evidence for Pleistocene Recharge in the Dakota Aquifer
- R L Stotler
Stotler, R.L. 2000. Isotopic Evidence for Pleistocene Recharge
in the Dakota Aquifer, Northeast Nebraska. BS Thesis,
College of Agricultural Sciences and Natural Resources,
Univ. Nebraska-Lincoln.
Geohydrology and Hydrochemistry of the Dakota Aquifer, Central United States
- R B Leonard
- D C Signor
- D G Jorgensen
- J O Helgesen
Leonard, R.B., Signor, D.C., Jorgensen, D.G., Helgesen, J.O.,
1984. Geohydrology and Hydrochemistry of the Dakota
Aquifer, Central United States. In: Jorgensen, D.G. (Ed.),
Geohydrology of the Dakota Aquifer, Proc. C.V., 1984.
(Ed.), Theis Conference on Geohydrology. National Water
Well Association, Worthington, OH, pp. 229-237.
Late Quaternary recharge determined from chloride in groundwater in the central Great Plains
- P A Macfarlane
- J F Clark
- M L Davisson
- G B Hudson
- D O Whittrmore
Macfarlane, P.A., Clark, J.F., Davisson, M.L., Hudson, G.B.,
Whittrmore, D.O., 2000. Late Quaternary recharge determined from chloride in groundwater in the central Great
Plains. Quat. Res. 53, 167-174.
Application of strontium and other radiogenic tracer isotopes to paleohydrologic studies
- Z E Peterman
- J S Stuckless
Peterman, Z.E., Stuckless, J.S., 1992. Application of strontium
and other radiogenic tracer isotopes to paleohydrologic
studies. In: Paleohydrogeological Methods and Their Applications. Proc. NEA Workshop, pp. 59-84.
Regional study of the Dakota Aquifer (Darton's Dakota revisited)
- Helgeson
Region 13, Western Glaciated Plains
- Lennox
The Glacial Lake Agassiz: USGS Monograph 25
- W Upham