SUPERHOT FLUIDS: THE ORIGIN AND FLUX OF NATURAL GREENHOUSE GASES IN VOLCANIC AREAS

Abstract

What are the sources and pathways to the surface of naturally emitted gases from volcanic-hosted geothermal systems? Subduction zones are a major conduit for the loss of volatiles, and New Zealand is one of the most active arc systems on Earth. Yet, the amount of gas emitted across the central North Island’s volcanic region is poorly constrained. Recent research in New Zealand’s Taup? Volcanic Zone has overturned a twenty-year paradigm by showing that shallow (~5 km) magmatic intrusions may not be the basis for surface expressions of gas and heat in New Zealand’s gas-rich geothermal systems. We thus hypothesise that geothermal gases have deep roots located where zones of partial melt (>8 km) meet crustal discontinuities. These discontinuities (e.g. faults or accommodation zones) act as highways to bring subduction and magmatic gases to the surface.
We will use a combination of melt and fluid inclusion and mineral noble gas isotope analyses, with surface gas and flux measurements, to trace the origin, transport, and interaction of gases within the Taup? Volcanic Zone crust. Such as a doctor with a stethoscope we want to investigate the breathing of the volcanic area in the great Taupo-Rotorua area.
Here we are presenting this new and exciting project funded by the Royal Society Te Aparangi Marsden Fund from June 2019 to June 2022, highlighting the key research objectives and the relevance and linkages of this project.
We believe this project presents a great opportunity to better understand geothermal natural emission, offering a potential t2019 (time reference for future surveys) baseline for future utilisation and exploration as well as emission control.