Stratigraphy and structure of the Canas Dulces caldera (Costa Rica)
Por:
Molina F., Martí J., Aguirre G., Vega E., Chavarría L.
Publicada:
1 nov 2014
Categoría:
Geology
Resumen:
The Ca (n) over tilde as Dulces caldera is home to the Rincon de la
Vieja-Santa Maria active volcanic complex and forms part of the
northwestern sector of the inner magmatic arc of Costa Rica, together
with other calderas and the active volcanoes of Miravalles, Tenorio, and
Orosi-Cacao. This caldera is the site of one of the main geothermal
reservoirs in Costa Rica, on which it is planned to build two geothermal
plants, each with a capacity of 55 MW. Nevertheless, the characteristics
of the Ca (n) over tilde as Dulces caldera are not well known due to the
fact that most of its morphological and structural traits are masked by
the products emitted recently by the Rincon de la Vieja-Santa Maria
volcanoes. Based on a revision of extensive deep boreholes and
geophysical data obtained by the Instituto Costarricense de Electricidad
(ICE) since 1970, combined with new geological work and radiometric
dating, we describe in the present study the stratigraphy, structure,
and volcanic evolution of this collapse caldera and define a
comprehensive model to describe its evolution. The Ca (n) over tilde as
Dulces caldera resulted from the massive eruption at 1.43 +/- 0.09 Ma of
similar to 200 km(3) of rhyolitic magma that was largely responsible for
the formation of the Liberia ignimbrite. The caldera was formed under
strong structural control dominated by two parallel NESW regional faults
and was followed by the construction of the Rincon de la Vieja-Santa
Maria volcanic complex on one of the caldera's structural borders. The
formation of this caldera and of a new shallow magmatic system
facilitated the installation of the highly productive geothermal system
inside the caldera.
Filiaciones:
Molina F.:
Área de Geociencias, Centro de Servicios Recursos Geotérmicos, Instituto Costarricense de Electricidad, Guanacaste, 50601, Costa Rica
Martí J.:
Institute of Earth Sciences Jaume Almera, Spanish National Research Council (CSIC), Barcelona, 08028, Spain
Aguirre G.:
Univ Nacl Autonoma Mexico, Ctr Geociencias, Queretaro 76230, Mexico
Centro de Geociencias, Universidad Nacional Autónoma de México, Querétaro, 76230, Mexico
Vega E.:
Área de Geociencias, Centro de Servicios Recursos Geotérmicos, Instituto Costarricense de Electricidad, Guanacaste, 50601, Costa Rica
Chavarría L.:
Área de Geociencias, Centro de Servicios Recursos Geotérmicos, Instituto Costarricense de Electricidad, Guanacaste, 50601, Costa Rica
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