Application and reliability of calcic amphibole thermobarometry as inferred from calc-alkaline products of active geothermal areas in the Andes

The Holocene products of the Ecuadorian Chachimbiro geothermal area indicate amphibole crystallization from 7 to 17 km depth at temperature conditions in the range of 800-910 °C. The occurrence of two separated regions of magma storage at approximately 230 ± 30 MPa and 380 ± 60 MPa is discussed. They should be taken into account as heat sources for this Ecuadorian geothermal area.