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| Titel |
Geochemical and geophysical monitoring activities in Campo de Calatrava Volcanic Field (Spain) |
| VerfasserIn |
Natividad Luengo-Oroz, Víctor Villasante-Marcos, Rubén López-Díaz, Marta Calvo, Helena Albert, Itahiza Domínguez Cerdeña |
| Konferenz |
EGU General Assembly 2017
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| Medientyp |
Artikel
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| Sprache |
en
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 19 (2017) |
| Datensatznummer |
250149783
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| Publikation (Nr.) |
 EGU/EGU2017-14171.pdf |
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| Zusammenfassung |
| The Campo de Calatrava Volcanic Field (CCVF) or Spanish Central Volcanic Zone is located
in central continental Spain (Ciudad Real province) and covers about 5000 km2. It includes
around 240 eruptive centers, mainly monogenetic basaltic cones but also explosive maar
structures. According to K-Ar geochronology, its main activity phase occurred during
Pliocene and Pleistocene epochs (between 5 and 1.7 Ma) and involved alkaline to
ultraalkaline magmas, although an older ultrapotassic phase is dated around 8.7-6.4 Ma.
However, some recent works have proposed Holocene ages for some of the volcanic products,
opening the possibility of considering the CCVF “active” according to international
standards.
Responding to this situation, the Instituto Geográfico Nacional (IGN) has initiated
geochemical and geophysical monitoring activities in the CCVF. Here, we describe these
ongoing efforts and we report results about groundwater geochemistry at several
natural highly-gaseous springs in the area (hervideros), as well as soil temperature,
CO2 diffuse flux from the soil and electrical self-potential data mapped on a small
degassing structure called La Sima. In order to analyze microseismicity or any seismic
anomaly in the CCVF, a seismic station has also been installed close to this degassing
structure.
Physicochemical parameters (temperature, pH, Eh and electric conductivity) were
measured in situ in four springs and samples were taken in order to analyze major ions and
trace elements. Total composition of dissolved gases and helium isotopic ratios were also
determined.
To complete soil temperature, self-potential and gas prospections performed in La Sima,
soil gases were sampled at the bottom of the structure at a depth of 20 cm. Analysis of the
total gas composition found 957400 ppm of CO2. Low values of O2 and N2 were also
detected (5600 and 24800 ppm respectively). |
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