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Fig. 10. Plot of Ca vs. NO3 concentrations of La Clape groundwaters. Highlighted in grey, dots of waters showing NO3 excess (See Fig. 3c, 3e, 9a and 9b) fall on a line corresponding to a NO3/Ca molar ratio of 1:2. This suggests an anthropogenic input related to the overuse of Ca(NO)-HO fertiliser by vineyards.

Figure 10 Plot of Ca vs. NO3 concentrations of La Clape groundwaters. Highlighted in grey, dots of waters showing NO3 excess (See Fig. 3c, 3e, 9a and 9b) fall on a line corresponding to a NO3/Ca molar ratio of 1:2. This suggests an anthropogenic input related to the overuse of Ca(NO)-HO fertiliser by vineyards.

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Fig. 1. (a) Geological sketch map of the study area, showing regional geology, sample and rain gauge locations and A-B cross section. Faults and overthrusts are not shown. (L Location of the Lézignan 1 deep drilling, (LC) Location of the La Clape 1 deep drilling. (b) A-B simplified cross-section from the Garrigues zone (part of the Corbiére: overthrust) to the La Clape horst and the Mediterranean Sea. rived from fossil seawater which has evolved through water-rock interaction (Schmerge, 2001; Aquilina et al., 2002; Hébrard et al., 2006; Duriez et al., 2007), and (3) water-rock interaction with Tri- assic evaporites (Mongelli et al., 2013). Pollution may overlap with concomitant salinisation processes (Gimenez Forcada and Morell Evangelista, 2008; Cary et al., in press). In future, decreasing mete- oric water inputs, increasing temperatures and rising sea level, be- cause of global warming and climate change, will enhance the salinisation processes in Mediterranean coastal aquifers (W6ppel- mann and Marcos, 2012; Feng et al., 2013). After 2025, Mediterra- nean countries will likely be impacted by climatic change, which will increase fresh groundwater resource losses (DETR, 1997; Arnell, 1999; Ranjan et al., 2006; Kundzewicz and D6ll, 2009). At a regional scale, several groundwaters with high salinities can be found. At Balaruc, Aquilina et al. (2002) identified mixing of karst waters with deep fossil thermal waters. An additional two karst springs with Cl concentrations of 39 mmol/L and 34 mmol/L, respectively, are located in the eastern Corbiéres massif in the SW of the study area (Doerfliger et al., 2004; Hébrard et al., 2006). Finally, 8 km NE of Balaruc, in the La Gardiole massif, a karst spring water has average Cl concentrations of 54 mmol/L (Hébrard et al., 2006). Based on temperature, Pco, and Li/SO, ratios greater than that of current seawater, Hébrard et al. (2006) concluded that butions of deep saline waters, which are usually warmer and de-
Fig. 1. (a) Geological sketch map of the study area, showing regional geology, sample and rain gauge locations and A-B cross section. Faults and overthrusts are not shown. (L Location of the Lézignan 1 deep drilling, (LC) Location of the La Clape 1 deep drilling. (b) A-B simplified cross-section from the Garrigues zone (part of the Corbiére: overthrust) to the La Clape horst and the Mediterranean Sea. rived from fossil seawater which has evolved through water-rock interaction (Schmerge, 2001; Aquilina et al., 2002; Hébrard et al., 2006; Duriez et al., 2007), and (3) water-rock interaction with Tri- assic evaporites (Mongelli et al., 2013). Pollution may overlap with concomitant salinisation processes (Gimenez Forcada and Morell Evangelista, 2008; Cary et al., in press). In future, decreasing mete- oric water inputs, increasing temperatures and rising sea level, be- cause of global warming and climate change, will enhance the salinisation processes in Mediterranean coastal aquifers (W6ppel- mann and Marcos, 2012; Feng et al., 2013). After 2025, Mediterra- nean countries will likely be impacted by climatic change, which will increase fresh groundwater resource losses (DETR, 1997; Arnell, 1999; Ranjan et al., 2006; Kundzewicz and D6ll, 2009). At a regional scale, several groundwaters with high salinities can be found. At Balaruc, Aquilina et al. (2002) identified mixing of karst waters with deep fossil thermal waters. An additional two karst springs with Cl concentrations of 39 mmol/L and 34 mmol/L, respectively, are located in the eastern Corbiéres massif in the SW of the study area (Doerfliger et al., 2004; Hébrard et al., 2006). Finally, 8 km NE of Balaruc, in the La Gardiole massif, a karst spring water has average Cl concentrations of 54 mmol/L (Hébrard et al., 2006). Based on temperature, Pco, and Li/SO, ratios greater than that of current seawater, Hébrard et al. (2006) concluded that butions of deep saline waters, which are usually warmer and de-
Table 1
Table 1
Fig. 2. On a Piper diagram, chemical composition of the La Clape groundwater evolves from Ca-HCO3 type waters to that of Na-Cl. Compositions of current seawater and of the average of Balaruc deep saline waters (Aquilina et al., 2002) are reported for comparison.
Fig. 2. On a Piper diagram, chemical composition of the La Clape groundwater evolves from Ca-HCO3 type waters to that of Na-Cl. Compositions of current seawater and of the average of Balaruc deep saline waters (Aquilina et al., 2002) are reported for comparison.
Fig. 3. (a-g) Binary plots between Cl and selected ions (expressed in mmol/L). The lines indicate the following dissolution or mixing processes: HDL for halite dissolution, DWML for mixing of Balaruc type deep saline water with shallow karst water (group A), SWML mixing of current seawater and shallow karst water (group A). Black arrows: trends related to potential water-rock interaction (WRI). White arrows: trends related to potential contamination (AC). (3 h) Evolution of Cl and Na concentrations of the groundwater at sites 8 and 11 from the rainy season (RS) to the dry one (DS).
Fig. 3. (a-g) Binary plots between Cl and selected ions (expressed in mmol/L). The lines indicate the following dissolution or mixing processes: HDL for halite dissolution, DWML for mixing of Balaruc type deep saline water with shallow karst water (group A), SWML mixing of current seawater and shallow karst water (group A). Black arrows: trends related to potential water-rock interaction (WRI). White arrows: trends related to potential contamination (AC). (3 h) Evolution of Cl and Na concentrations of the groundwater at sites 8 and 11 from the rainy season (RS) to the dry one (DS).
Fig. 5. On a Sr mixing diagram, most of the La Clape waters fall on a regression line (dashed line DWML) with the spring waters (group A) as the low mineralised end- member. Balaruc deep saline waters plot on the DWML. Two water samples (site 6) plot below the DWML and correspond to a rapid recharge toward a karst conduit connected to a sinkhole. They fall on another regression line WRIL, as well as the spring waters (group A) and with the local recharge waters as the low mineralised end-member (see text for further details).
Fig. 5. On a Sr mixing diagram, most of the La Clape waters fall on a regression line (dashed line DWML) with the spring waters (group A) as the low mineralised end- member. Balaruc deep saline waters plot on the DWML. Two water samples (site 6) plot below the DWML and correspond to a rapid recharge toward a karst conduit connected to a sinkhole. They fall on another regression line WRIL, as well as the spring waters (group A) and with the local recharge waters as the low mineralised end-member (see text for further details).
Fig. 4. (a) HCO3 as a function of Ca content. The lines indicate the following processes. CDCL line: congruent dissolution of calcite. DWML lines: mixing of shallow karst water with Balaruc type deep saline water. SWML line: mixing ot shallow karst water with current seawater. For the groundwater of sites 3 and © (highlighted in grey) anthropogenic input may also be the source of excess Ca. (b’ open-system (solid line) and closed-system (broken line) carbonate evolution paths. For the La Clape groundwater, calcite dissolution mainly occurs in an open- system with a HCO3/TDIC ratio close to 1.
Fig. 4. (a) HCO3 as a function of Ca content. The lines indicate the following processes. CDCL line: congruent dissolution of calcite. DWML lines: mixing of shallow karst water with Balaruc type deep saline water. SWML line: mixing ot shallow karst water with current seawater. For the groundwater of sites 3 and © (highlighted in grey) anthropogenic input may also be the source of excess Ca. (b’ open-system (solid line) and closed-system (broken line) carbonate evolution paths. For the La Clape groundwater, calcite dissolution mainly occurs in an open- system with a HCO3/TDIC ratio close to 1.
Mg?*, Ca?*, Sr?* concentrations and ®’Sr/®°Sr ratios of calcite and clayey phases from rocks of the La Clape massif. ®’Sr/®°Sr ratios of the western Mediterranean seawater measured by acid leaching of oyster shells. 87Sr/®°Sr ratios of 3 soils leached with local rainwaters and of an anti-mildew fungicide currently used in some vineyards of the La Clape massif.
Mg?*, Ca?*, Sr?* concentrations and ®’Sr/®°Sr ratios of calcite and clayey phases from rocks of the La Clape massif. ®’Sr/®°Sr ratios of the western Mediterranean seawater measured by acid leaching of oyster shells. 87Sr/®°Sr ratios of 3 soils leached with local rainwaters and of an anti-mildew fungicide currently used in some vineyards of the La Clape massif.
Table 4 Fig. 6. (a and b) Batch experiment of a powdered LKU limestone sample in the local rainwater (RW). Variations in Sr isotopic ratio of the water with time (a) and with the inverse of Sr contents (b) are consistent with a simple two-component mixing between rainwate! and an easily leachable Sr removed from the LKU limestone which is more radiogenic than that of the calcite. (c) Plots in the Sr mixing diagram of the WRIL line of Fig. 5 with the evaporated rainwater (EWR) as an end-member and of Sr data from the batch experiment with the rainwater (RW) as an end-member. Water-rock interaction of recharge water with the host limestones in the upper part of the karst aquifer provides a somewhat similar S1 isotopic signature of 0.707840 (y-intercept of WRIL) and 0.707813 (batch experiment).
Table 4 Fig. 6. (a and b) Batch experiment of a powdered LKU limestone sample in the local rainwater (RW). Variations in Sr isotopic ratio of the water with time (a) and with the inverse of Sr contents (b) are consistent with a simple two-component mixing between rainwate! and an easily leachable Sr removed from the LKU limestone which is more radiogenic than that of the calcite. (c) Plots in the Sr mixing diagram of the WRIL line of Fig. 5 with the evaporated rainwater (EWR) as an end-member and of Sr data from the batch experiment with the rainwater (RW) as an end-member. Water-rock interaction of recharge water with the host limestones in the upper part of the karst aquifer provides a somewhat similar S1 isotopic signature of 0.707840 (y-intercept of WRIL) and 0.707813 (batch experiment).
Fig. 7. Stable isotope compositions (87H vs. 5'80) of the La Clape groundwater. Broken line LMWL is the local meteoric water line (Ladouche et al., 2009). Solid line SWML and dashed line DWML correspond to mixing of the shallow karst water (group A) with the current seawater or the Balaruc type deep saline water, respectively.
Fig. 7. Stable isotope compositions (87H vs. 5'80) of the La Clape groundwater. Broken line LMWL is the local meteoric water line (Ladouche et al., 2009). Solid line SWML and dashed line DWML correspond to mixing of the shallow karst water (group A) with the current seawater or the Balaruc type deep saline water, respectively.
Fig. 8. Relationship between *°CI/Cl and 1/Cl for selected waters of group C. Deep water mixing domain DWMD is defined by the mixing of Balaruc type deep saline waters and local rainwater or thermonuclear pulse rainwater after evaporation. Seawater mixing domain, SWMD, is defined by the mixing of current seawater and local rainwater.
Fig. 8. Relationship between *°CI/Cl and 1/Cl for selected waters of group C. Deep water mixing domain DWMD is defined by the mixing of Balaruc type deep saline waters and local rainwater or thermonuclear pulse rainwater after evaporation. Seawater mixing domain, SWMD, is defined by the mixing of current seawater and local rainwater.
Fig. 9. (a) Ca content as a function of Pco2. (5a), Dotted lines: curves for Ca content at equilibrium with calcite at 10 and 15 °C. Ca contents measured and theoretically modelled with PHREEQC are shown for each water sample of groups A and B. (b) Dashed lines: curves for an initial equilibrium with calcite followed by mixing with deep saline water for mixing ratios varying between 3% and 15%. Solid line: curve for an initial equilibrium with calcite followed by a mixing with current seawater for a mixing ratio of 4%. The degassing paths are outlined by arrows, joining the measured and the modelled values. Sites 3 and 9 showing Ca excess due to anthropogenic input are highlighted in grey.
Fig. 9. (a) Ca content as a function of Pco2. (5a), Dotted lines: curves for Ca content at equilibrium with calcite at 10 and 15 °C. Ca contents measured and theoretically modelled with PHREEQC are shown for each water sample of groups A and B. (b) Dashed lines: curves for an initial equilibrium with calcite followed by mixing with deep saline water for mixing ratios varying between 3% and 15%. Solid line: curve for an initial equilibrium with calcite followed by a mixing with current seawater for a mixing ratio of 4%. The degassing paths are outlined by arrows, joining the measured and the modelled values. Sites 3 and 9 showing Ca excess due to anthropogenic input are highlighted in grey.
Mixing ratios of saline deep water for the La Clape groundwater (B and C groups). Calculations are based on 4 tracers (Cl and Sr ionic and isotopic abundances). Table 5 equations (Faure, 1986). These calculations were performed for waters of groups B and C that fall on the DWML line (Fig. 5). The mixing ratios computed with different geochemical tracers are coherent (Table 5). These ratios range from 0% to 3% of the Balaruc type evolved saline deep water in group B waters and from 3% to 16% in group C waters (Table 5). 55.79 mg/L, only one water sample exceeds the French guideline (50 mg/L of NO3) for drinking waters. The S compounds that are widely used in vine growing as fungicides (S and SO,) could ex- plain some excess SO, observed in three water samples from site 9 (Table 1, Fig. 3f). The greatest SO, concentration (221 mg/L) found in the La Clape groundwater does not exceed the French drinking water guideline (250 mg/L of SO.). The highest NO3 and SO, concentrations in the la Clape groundwaters are observed at sites 3 and 9. These groundwater samples also show the highest Br/Clmoiar Fatios, in agreement with an anthropogenic origin of the positive Br/Clmola anomaly as previously assumed in Section 5.1.
Mixing ratios of saline deep water for the La Clape groundwater (B and C groups). Calculations are based on 4 tracers (Cl and Sr ionic and isotopic abundances). Table 5 equations (Faure, 1986). These calculations were performed for waters of groups B and C that fall on the DWML line (Fig. 5). The mixing ratios computed with different geochemical tracers are coherent (Table 5). These ratios range from 0% to 3% of the Balaruc type evolved saline deep water in group B waters and from 3% to 16% in group C waters (Table 5). 55.79 mg/L, only one water sample exceeds the French guideline (50 mg/L of NO3) for drinking waters. The S compounds that are widely used in vine growing as fungicides (S and SO,) could ex- plain some excess SO, observed in three water samples from site 9 (Table 1, Fig. 3f). The greatest SO, concentration (221 mg/L) found in the La Clape groundwater does not exceed the French drinking water guideline (250 mg/L of SO.). The highest NO3 and SO, concentrations in the la Clape groundwaters are observed at sites 3 and 9. These groundwater samples also show the highest Br/Clmoiar Fatios, in agreement with an anthropogenic origin of the positive Br/Clmola anomaly as previously assumed in Section 5.1.
Fig. 11. (a) Plotted on the Sr mixing diagram, saline groundwater and spring waters of 3 karst aquifers located along the Gulf of Lion seashore, fall on a trend RMT (y- intercept of 0.708472): (CG) Balaruc, («) Font Estramar, (+) Fontdame, (4) La Gardiole karst springs, (©) La Clape group C, (e) La Clape group B. Current seawater (SW) and calcites of upper Jurassic and lower Cretaceous limestones (CL) are reported for comparison. (b) On a Sr mixing diagram, the averages of Sr data for Balaruc, La Clape (group B and C), and Font Estramar groundwater plot on a regression line RML (y-intercept = 0.708557; R? = 0.99) (see text for further details).
Fig. 11. (a) Plotted on the Sr mixing diagram, saline groundwater and spring waters of 3 karst aquifers located along the Gulf of Lion seashore, fall on a trend RMT (y- intercept of 0.708472): (CG) Balaruc, («) Font Estramar, (+) Fontdame, (4) La Gardiole karst springs, (©) La Clape group C, (e) La Clape group B. Current seawater (SW) and calcites of upper Jurassic and lower Cretaceous limestones (CL) are reported for comparison. (b) On a Sr mixing diagram, the averages of Sr data for Balaruc, La Clape (group B and C), and Font Estramar groundwater plot on a regression line RML (y-intercept = 0.708557; R? = 0.99) (see text for further details).
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