PhD opportunity: source, content, and loss of the deep magmatic volatiles (CO2, He)

GNS Science and the University of Auckland, School of Environment, New Zealand, are seeking a highly motivated person for a funded 3-year PhD position. This is one of two open PhD positions funded by the Royal Society Te Aparangi - Marsden Fund.

This igneous petrology PhD project seeks to provide insight into the source, content, and loss of the deep magmatic volatiles (CO2, He) of the Taupo Volcanic Zone.

The student will acquire new data from phenocryst noble gas and isotopic analyses. This study will delineate different reservoirs of under-plated to mid-crustal magmas and reveal the potential role of not only primary magmas and subduction fluids, but also lower to mid crust melting during gas evolution.

This is part of a larger programme entitled "Superhot fluids: The origin and flux of natural greenhouse gases in volcanic areas" described below:

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 Taupo Volcanic Zone has overturned a twenty-year paradigm by showing that shallow (~5 km) magmatic intrusions are not 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 inclusion and mineral noble gas isotope analyses, with surface gas and flux measurements, to trace the origin, transport, and interaction of gases within the Taupo Volcanic Zone crust. The new definitive model of magmatic degassing and natural greenhouse gas emissions will offer greater understanding from source to surface of volatiles transfer in the New Zealand volcanic arc.

The student will be based in Auckland with a field base at GNS Science Wairakei Research Centre, Taupo area. International travel for analytical work is expected.

Candidates must have a top-quality MSc in geology (igneous geochemistry), or equivalent 4-5-year degree in geological sciences and a good university background in quantitative science (maths, physics, chemistry). A keen interest in analytical and laboratory work is essential, and experience with mass spectrometry is preferred.

For further information about the project, please contact Dr. Isabelle Chambefort.

Applications with a full CV including transcripts, and a personal motivation letter describing your expectations should be sent directly to Isabelle Chambefort (i.chambefort@gns.cri.nz) and Michael Rowe (michael.rowe@auckland.ac.nz). Application closes 6th February, 2019 for a starting date as soon as March 2019.

posted: 07 January 2019     Please mention EARTHWORKS when responding to this advertisement.