Medical Hydrology and Balneology: Environmental Aspects

Mineral waters in Azores islands: hydrogeo
logical approach and therapeutical applications
Carreiro-Nunes JC (1-2) , Carvalho JM (2) , Oliveira LC (2) , Carvalho MR (3)
(1) INOVA Institute. Ponta Delgada, Azores, Portugal
(2) Geosciences Department, Azores University, Portugal
(3) Lisbon University, Sciences Faculty, Geology Department, Lisbon, Portugal
jcnunes@uac.pt
Introduction and Objectives
In Azores Islands, located 1,815 km W of Portugal Mainland, in the North Atlantic
Ocean and at the Azores triple tectonic junction, occur several mineral and
thermal waters related to volcanism and circulation in volcanic formations (e.g.,
Carvalho et al., 2005; Carvalho et al., 2006; Cruz, 2004; Cruz & França, 2006;
Cabeças et al., 2010). Some of them are or were classified as natural mineral water
(Nunes et al., 2007) as, i) the Lombadas and Serra do Trigo CO2-rich waters, and ii)
waters used for balneotherapy and balneology as Furnas, Ferraria and Caldeiras da
Ribeira Grande (São Miguel Island), Varadouro ( Faial Island) and Carapacho
(Graciosa Island). In the commercial market it is also present the spring water
Gloria Patri (low mineralization) at São Miguel Island.
Materials and Methods
Typology of chemical composition is quite broad, resulting hydrogeological
conceptual models of several nature (Cruz, 2007), namely (Figure 1): (i) NaCl
thermal springs from the basal aquifer; (ii) thermal springs, boiling pools, fumaroles
and cold CO2-rich springs associated to hydrothermal systems. To those types must
be associated other springs resulting from suspended aquifers, spurring from paleosoils,
dykes, lithological contacts or other structures.
Current development projects (Nunes et al., 2007) are being carried out mainly
over thermal springs at sea level (e.g. Varadouro, Carapacho, and Ferraria) associated
with the basal aquifer and sea water heating.
At those sites several studied and works are in due course and include hydrogeological
surveys, isotopic and classical geochemistry, geophysical surveys and
evaluation and production drilled wells. The scope is to get resources able to be
recognized as natural mineral natural according to European and national law and
with the modern hygienical and sanitary standards.
Results
Those mineral waters have electrical conductivities from 6 to 47 mS/cm and
temperatures from 35ºC (Varadouro old spring), to 41ºC (Carapacho) and 62ºC
Balnea
2012, núm. 6, 231-232
231
ISBN: 978-84-669-1887-0
978-84-669-3482-4