HYDROTHERMAL ERUPTIONS AT THE DOMUYO GEOTHERMAL FIELD, ARGENTINA: ERUPTIVE DYNAMICS AND CONTROLS
Leandro D'Elia1, Gerardo Páez2, Irene R. Hernando1, Iván A. Petrinovic3
Affiliations: ^ 1^ Centro de Investigaciones Geológicas (CIG), CONICET - UNLP. ldelia@cig.museo.unlp.edu.ar 2 Instituto de Recursos Minerales (INREMI), CIC-UNLP 3 Centro de Investigaciones en Ciencias de la Tierra (CICTERRA), CONICET -- UNC.
Presentation type: Poster
Presentation time: Thursday 16:30 - 18:30, Room Poster Hall
Poster Board Number: 74
Programme No: 3.14.8
Abstract
Hydrothermal eruptions are explosive events driven by the sudden and violent vaporization of the water present in many geothermal fields worldwide. Over recent years, different thermodynamical conditions of fluids and petrophysical-geomechanical features of the host-rocks were mentioned as responsible for the wide range of eruptive styles and deposits generated by hydrothermal eruptions. Nevertheless, geological and historical records show that PDC and fallout processes are underestimated as common processes linked to hydrothermal eruptions. The pristine Holocene--historic hydrothermal eruptive record of the Domuyo Geothermal Field (Patagonia, Argentina) shows a series of contrasting eruptive scenarios. They are characterized by ballistic ejection, PDC and/or fallout deposits, each with a distinctive tefra-composition and granulometry, associated with both excavational and/or aggradational landforms. In this contribution we analyze and discuss how diverse eruptive dynamics are controlled by reservoir energy, depth of the explosion/fragmentation levels, physical properties and structural anisotropy of the host-rocks and eruptive center migrations. This case study is useful not only for the assessment of volcanic hazards associated with geothermal fields, but also contributes to the overall knowledge of the eruptive dynamics and controls influencing this kind of eruption.