Role of Water in island arc and continental flood basalt magma genesis
15 May 2019 12am AEST
30 Jun 2019 11pm AEST
Scholarship available to
This PhD project has two main parts and will involve training in advanced analytical techniques, including running the SHRIMP SI at ANU.
Changes in the water inventory of the deep mantle through time. The water contents of clinopyroxenes will be analysed that will provide minimum magmatic water contents) from the major continental flood basalt sequences (including selected ocean islands) through the Phanerozoic. We have samples from Karoo, Siberia, Parana, Deccan, Emishan and Ethiopia as well as Iceland and the Canaries. In preparation for this study we have undertaken preliminary water analysis on clinopyroxenes from the Parana basalts in Brazil that suggest magmatic water contents near 4 wt. % that are similar to island arc lavas. A similar result has emerged from the Tarim in NW China and we are excited to see if this is true throughout the Phanerozoic or if the water content of the source of these basaltic outpourings has changed through time. If sufficiently unaltered material can be obtained from Precambrian basalts and komatiites we will endeavour to extent the record as far back in Earth history as possible. We have previously worked on komatiite glass inclusions for trace element abundances and alkali metals and a natural extension of this work is to look for water concentrations. The results will inform models for the role of water in plate tectonics over Earth history and inform efforts to address the atmospheric impact of these immense eruptions.
Volatile evolution of arc magmas during ascent. The project will also investigate samples from both before and after the major caldera-forming basaltic-andesite eruptions on Tofua volcano, Tonga, to determine whether there was a change in the degassing and crystallisation styles between caldera-forming and effusive eruptions. In addition, clinopyroxenes from both andesite and dacite lavas on adjacent Fonualie will be analysed to ascertain whether degassing and crystallisation histories differ for more silicic magmas. By analysing clinopyroxenes with a range of Mg#’s the project will distinguish between polybaric degassing and isobaric crystallization in the magmas. It will undertake a comparison with volcanic products from system built on thick crust (e.g. Parinacota in the Andes) to assess whether changes in crustal thickness influence magma differentiation and degassing.
This PhD project forms part of DP190102760 and will be co-supervised by Professor Trevor Ireland at ANU who will oversee the SHRIMP-SI analytical work.
This scholarships are available to eligible candidates to undertake a direct entry 3-year PhD program.
To be eligible for a scholarship, applicants are expected to have a record of excellent academic performance and preferably, additional relevant research experience and/or peer-reviewed research activity in line with the University’s scholarship rating guidelines. Refer to the Rating Scholarship Applicants section for more information about these guidelines.
The scholarship is comprised of a Tuition Fee Offset and a Living Allowance Stipend. The value and tenure of the scholarship is a “MQRES” full-time stipend rate of $27,596 per annum (in 2019 tax exempt for up to 3 years - indexed annually).
Indigenous candidates will also be eligible for a top-up stipend/living allowance.
Name: Professor Simon Turner
Phone: 0400 101 367
How to Apply
For information on how to apply, select the "How to Apply" button below.
Please note, at the start of your application you should select the scholarship type of "HDR Project/Supervisor Specific Scholarship".