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| Titel |
Preliminary hydrochemical study of Ronda ultramafic massif (South Spain) |
| VerfasserIn |
Iñaki Vadillo, Begoña Urresti, Pablo Jiménez, Sergio Martos, Juan Jose Duran, José Benavente, Francisco Carrasco, Antonio Pedrera |
| Konferenz |
EGU General Assembly 2016
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 18 (2016) |
| Datensatznummer |
250132740
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| Publikation (Nr.) |
 EGU/EGU2016-13275.pdf |
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| Zusammenfassung |
| During 2015 more than 70 springs related to the peridotite outcrops of the Ronda
mountainous massif, South Spain, have been identified. The field work included “in situ”
measurements of physical-chemical parameters (T, EC, pH), and water sampling for major
components and stable isotopes of water and DIC.
The hydrogeochemical study allowed us to characterize different flow systems: (1)
springs with very low to medium electrical conductivities (200-700 μS/cm) and pH below
9.0, and (2) springs with EC above 700 μS/cm and pH above 9.0.
The first group of springs are supposed to be linked with surface and subsurface flows.
The hydrogeochemical reactions that determine their composition are characterized by the
low solubility of minerals, atmospheric CO2 (open system) and active serpentinization
reactions that supplies hundreds of ppm of Mg2+. All of them are waters of HCO3-Mg or
HCO3-Mg-Na type.
The second group of springs drains water with EC above 700 μS/cm and pH over 9. In
general, these springs are associated to deep flows connected to regional faults or major
tectonic features. Deeper flow enhances water-rock interaction and time of contact, so this
system evolves towards a closed system to O2 and CO2. All these waters are old or older
than the first group and show reducing features and are of Na-Cl or OH-Ca type. |
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