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Melting conditions beneath the Newer Volcanics Province from probabilistic inversions

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posted on 09.09.2022, 03:20 authored by Kelly Vaughan-Taylor

The Newer Volcanics Province (NVP) represents mainland Australia’s youngest intraplate volcanism. Despite past studies, the exact mechanism of magma generation is heavily debated, with the exact source composition and melting environments remaining unclear. Previous models of NVP magma genesis have tended to focus on either geochemical or geophysical arguments. In this work, we use an integrated approach using both geochemical and geophysical observations to explain mantle processes. Geochemical data from the NVP is screened to obtain a dataset containing <2 Ma samples that represent primitive melts from peridotitic sources. A newprobabilistic inversion method is applied to the samples in conjunction with a recently developed mantle melting model to evaluate the melting conditions in the mantle. A separate geophysical model of the present-day thermochemical structure of the lithosphere and sublithospheric upper mantle is created by jointly inverting available seismic datasets. The results from the geochemical and the geophysical models suggest the presence of a thin, hot lithosphere. Furthermore, findings indicate the source is relatively depleted in all major elements except FeO but enriched in rare earth elements. The source is also suggested to have developed this signature due to a substantial input from the sub-continental lithosphere mantle.

History

Table of Contents

1 Introduction -- 2 Data -- 3 Methodology -- 4 Results -- 5 Discussion - References -- Appendices

Notes

A thesis submitted to Macquarie University for the degree of Master of Research

Awarding Institution

Macquarie University

Degree Type

Thesis MRes

Degree

Thesis (MRes), Macquarie University, Faculty of Science and Engineering, 2020

Department, Centre or School

Department of Earth and Environmental Sciences

Year of Award

2020

Principal Supervisor

Juan Carlos Afonso

Additional Supervisor 1

Heather Handley

Rights

Copyright: The Author Copyright disclaimer: https://www.mq.edu.au/copyright-disclaimer

Language

English

Jurisdiction

Australia

Extent

84 pages