Options
Preliminary Geochemical and Isotopic Results in Thermal and Cold Waters of Graciosa Volcanic Island (Azores)
Author(s)
Language
English
Obiettivo Specifico
2V. Struttura e sistema di alimentazione dei vulcani
Status
Published
JCR Journal
N/A or not JCR
Peer review journal
Yes
Title of the book
Issue/vol(year)
/17 (2017)
Publisher
Elsevier
Pages (printed)
630-633
Issued date
2017
Subjects
Abstract
Graciosa Island is located in the Azores Archipelago, along the so-called Terceira Rift, NE boundary of the Azores Plateau. From
the hydrochemical point of view, two types of Na-Cl groundwater systems were identified: a cold aquifer system emerging at
springs and exploited through boreholes for public water supply with different degrees of mineralization, and a hydrothermal
system with issuing temperatures around 45 ºC. Geothermometers applied to the thermal waters point to deep temperature around
167 ºC and to immature waters, not reaching complete equilibrium with the reservoir rock. The isotopic composition and
geochemistry of the thermal waters indicate mixture groundwater - seawater in different percentages and ion-exchange
mechanisms that will be able to: i) increase groundwater salinity, ii) strongly change the isotopic composition to more enriched
values, with different degrees of mixing.
the hydrochemical point of view, two types of Na-Cl groundwater systems were identified: a cold aquifer system emerging at
springs and exploited through boreholes for public water supply with different degrees of mineralization, and a hydrothermal
system with issuing temperatures around 45 ºC. Geothermometers applied to the thermal waters point to deep temperature around
167 ºC and to immature waters, not reaching complete equilibrium with the reservoir rock. The isotopic composition and
geochemistry of the thermal waters indicate mixture groundwater - seawater in different percentages and ion-exchange
mechanisms that will be able to: i) increase groundwater salinity, ii) strongly change the isotopic composition to more enriched
values, with different degrees of mixing.
References
1. Cruz VJ, França Z. Hydrogeochemistry of thermal and mineral water springs of the Azores archipelago (Portugal). Journal of Volcanology and
Geothermal Research 2006; 151: 382-298.
2. Nunes JC, Lima EA. Geodiversidade da Ilha Graciosa, Açores. Açoreana - Revista de Estudos Açoreanos 2005; 10 (2): 319-343 (in
Portuguese).
3. Carvalho MR, Carreira PM, Marques JM, Capasso G, Grassa F, Nunes JC. Geochemistry of groundwater from Graciosa Island (Azores): a
contribution to the hydrothermal system conceptual model. Mineralogical Magazine 2011; 75 (3): 630
Geothermal Research 2006; 151: 382-298.
2. Nunes JC, Lima EA. Geodiversidade da Ilha Graciosa, Açores. Açoreana - Revista de Estudos Açoreanos 2005; 10 (2): 319-343 (in
Portuguese).
3. Carvalho MR, Carreira PM, Marques JM, Capasso G, Grassa F, Nunes JC. Geochemistry of groundwater from Graciosa Island (Azores): a
contribution to the hydrothermal system conceptual model. Mineralogical Magazine 2011; 75 (3): 630
Type
article
File(s)
No Thumbnail Available
Name
Carreira et al 2017 WRI15.pdf
Size
248.99 KB
Format
Adobe PDF
Checksum (MD5)
0ffaea69b84f62853ac9c899235a64b5