There are remains of a caldera rim 1 km southeast of the main crater. Mogote hills and mountains in the west and the Holy Spirit and Drop of Water in the Southeast are remnants of a paleo-caldera of 200km2. It features an extended flat region consists of fluvial-volcanic landfill located between the edges of the caldera and cone Miravalles.
Associated with emission of lava flows and pyroclastic deposits as products ignimbrite ash, pumice and compacted blocks.
Furthermore, filler deposit fluvial-lake.
The history of the volcano Miravalles-Guayabo can be summarized as:
Quaternary basaltic volcanoes Building “Guayabo volcano.”
Between 1.6 and 0.6 million years: fiery clouds (ignimbrites) and subsidence of the volcano Guayabo (Gillot et al., 1994).
Fill caldérica depression.
400 000 years ago: Rejuvenation of volcanic activity and volcanic origin Massif Cabro Muco-La Giganta.
About 10 000 years ago: Paleo-Miravalles growth, migration of volcanic activity to the southwest and lower caldérica structure development.
8200 years ago: Current Development Miravalles cone. Lava flows and lahars generated hot avalanches.
8000 years ago: lava flows and pyroclastic deposits.
1946 (September 14): geothermal fluids in the subsurface water table causing a small explosion in the southwestern flank of Miravalles.
Current status of activity
Secondary type volcanic activity (solfataras, batideros mud and hot springs) in the area called “The Burners”.
Volcano monitoring systems
The ICE is in the volcano Miravalles 6 seismic stations and accelerograph located in the Miravalles Geothermal Field, plus a network of 10 stations inclinometry dry, precise leveling studies and microgravity.
The OSIVAM monitors around this volcano seismicity (seismic and strong motion equipment).