Sie befinden Sich nicht im Netzwerk der Universität Paderborn. Der Zugriff auf elektronische Ressourcen ist gegebenenfalls nur via VPN oder Shibboleth (DFN-AAI) möglich. mehr Informationen...
Influence of the paleogeographic evolution on the groundwater salinity in a coastal aquifer. Cabo de Gata aquifer, SE Spain
Ist Teil von
Journal of hydrology (Amsterdam), 2018-02, Vol.557, p.55-66
Ort / Verlag
Elsevier B.V
Erscheinungsjahr
2018
Link zum Volltext
Quelle
Alma/SFX Local Collection
Beschreibungen/Notizen
•Groundwater salinity in Cabo de Gata coastal aquifer is higher than seawater.•The groundwater age was estimated between 7000 and 10,000 years BP.•This age was determined with isotopic data coupled to water masses mixing modeling.•The paleogeographic reconstruction suggests the existence of a Holocene coastal lagoon.•The evaporation process determines the high groundwater salinity.
The groundwater of the Cabo de Gata detritic aquifer, in southeastern Spain, exhibit salinities of between 70–726 mmol/L of Cl− (brackish-salt to hypersaline waters). We have investigated the causes of the high salinity anomaly, which at certain points exceeds that of present-day seawater (600 mmol/L). Two hypotheses are considered as possible sources for the saline water: (1) The deeper, more saline groundwater date back to an old marine intrusion that occurred at the end of the last Ice Age (14–17 ka), when seawater salinity was higher than in the present day. This hypothesis is supported by the values of 14C measured in this water (∼6–10 pmc), which indicate old water of up to 17 ka. However, the values of 18O and 2H are lower than would be expected. (2) The water is the result of mixing between fresh groundwater and seawater. The latter explanation agrees well with the low values of 18O and 2H. This mixture is later subject to evaporation, explaining its high salinity. Hydrogeochemical modelling was carried out for the most saline samples, assuming such mixing between freshwater and seawater followed by evaporation, and the results show a very good agreement between the measured and simulated values. According to the model calculation, the original mixture contained approximately 60% seawater and its volume subsequently was reduced through evaporation by around 30%. This mixing and evaporation could occur during the Flandrian Transgression (6000–8000 y), when this area accommodated a coastal lagoon.