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Hipótesis sobre el origen de la salinidad de las aguas subterráneas en la isla de Fuerteventura, Archipiélago de Canarias
| Content Provider | Semantic Scholar |
|---|---|
| Author | Herrera, C. |
| Copyright Year | 2003 |
| Abstract | The hydrogeochemical and isotopic study from the central area of Fuerteventura Island shows that groundwater presents high salinity, which increases downwards. In the Basal Complex of the Betancuria massif it is possible to differenciate an Upper Unit, with groundwater of relatively moderate electrical conductivity (2.5-5.5 μS/cm) and temperature between 18 and 25oC that broadly corresponds to submarine vulcanites, and a Lower Unit, with groundwater of a higher salinity (5.5 to 24 μS/cm) and temperature between 25 and 30oC, that mostly coincides with intrusive rocks. Groundwater from the Upper Unit are brackish and of the sodium chloride type, generally with moderate alkalinity, low sulphate and silica contents, and nitrate contents variable from one place to another. The more saline waters from the Lower Unit are of the sodium chloride-sulphate type, with high silica contents and without nitrates, but for occasional mixing with Upper Unit waters flowing down the boreholes. The high salinity of the Upper Unit groundwater is mostly the consequence of the island climatic aridity; it is mostly explainable by evapoconcentration of rainwater, with a minor effect of water-rock interaction, that manifests mostly as a sodium excess over chloride due to silicate mineral weathering. However, to explain the more saline groundwater from the Lower Unit other salinity sources have to be considered. After the values of the Cl/ Br ratio, of the most relevant ionic ratios, and of the study of water and sulphur isotopes, with the help of hydrochemical modelling, the salinity can probably be explained as a mixing with relict marine water existing in the intrusive rocks of the Basal Complex. The very low and heterogeneous macroscopic permeability of the |
| Starting Page | 433 |
| Ending Page | 452 |
| Page Count | 20 |
| File Format | PDF HTM / HTML |
| Volume Number | 114 |
| Alternate Webpage(s) | http://www.igme.es/boletin/2003/114_4_2003/ARTICULO%206.pdf |
| Language | English |
| Access Restriction | Open |
| Content Type | Text |
| Resource Type | Article |
