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| Titel |
The Cerro Aguas Calientes caldera, NW Argentina: an example of a tectonically controlled, polygenetic, collapse caldera, and its regional significance |
| VerfasserIn |
Ivan A. Petrinovic, Joan Martí, Gerardo J. Aguirre-Diaz, Silvina R. Guzmán, Adelina Geyer, Pablo Grosse, Natalia Salado Paz |
| Konferenz |
EGU General Assembly 2010
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| Medientyp |
Artikel
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| Sprache |
Englisch
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| Digitales Dokument |
PDF |
| Erschienen |
In: GRA - Volume 12 (2010) |
| Datensatznummer |
250034178
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| Zusammenfassung |
| Polygenetic, silicic collapse calderas such as Cerro Galán, Pastos Grandes, La Pacana,
Vilama, Negra Muerta, Farallón Negro, Cerro Guacha, among others are common in the
central Andes. Here we describe in detail the Cerro Aguas Calientes caldera in NW
Argentina, which comprises two caldera-forming episodes occurred at 17.15 Ma
and 10.3 Ma, respectively. We analyse the significance of its structural setting,
composition, size and the subsidence style of both caldera episodes. Our results reveal
that the caldera eruptions had a tectonic trigger. In both cases, an homogeneous
dacitic crystal-rich (>60 vol. % of crystals) reservoir of batholitic size became
unstable due to the effect of increasing regional transpression, favouring local dilation
throughout minor strike slip faults from which ring faults nucleated and permitted caldera
collapse.
Both episodes are similar in shape, location and products of the resulting calderas.
The 17.15 Ma caldera has an elliptical shape (17 Ã 14 km) and is elongated in
a N30º trend; both intracaldera and extracaldera ignimbrites covered an area of
around 620 km2 with a minimum volume estimate of 138 km3 (DRE). The 10.3 Ma
episode generated another elliptical caldera (19 Ã14 km), with the same orientation as
the previous one, from which intracaldera and outflow ignimbrites covered a total
area of about 1,700 km2, representing a minimum eruption volume of 341 km3
(DRE).
In this work we discuss the significance of the Cerro Aguas Calientes caldera in
comparison with other well known examples from the central Andes in terms of tectonic
setting, eruption mechanisms, and volumes of related ignimbrites. We suggest that our
kinematic model is a common volcano-tectonic scenario during the Cenozoic in the Puna and
Altiplano, which may be applied to explain the origin of other large calderas in the same
region. |
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