Plate tectonic processes acting over billions of years govern Earth's deep geochemical cycles and control the composition of the mantle, the crust and atmosphere. Basaltic lavas have been used for decades to determine the mantle's composition. However, they homogenise during magma mixing, meaning that the full extent of mantle heterogeneity and thus models of Earth dynamics and evolution are still poorly constrained.

This PhD project aims to more accurately determine Earth's mantle composition by examining volcanoes that sample the deep mantle at hotspot localities. Instead of analysing bulk rock lavas we will analyse the combined trace element and Sr-Nd-Pb isotope compositions of deeply formed olivine-hosted melt inclusions (MIs) from Reunion and Iceland. Isotopic analysis of MIs is now possible owing to our success in developing and applying new detector technology in thermal ionisation mass spectrometry (TIMS) that led to an order of magnitude improvement of the precision for analyses of small samples. Acquired data will be used in combination with melt mixing models to re-evaluate and adjust current global models of mantle convection, plate recycling and melt transport from mantle to crust. The modelling work will be in collaboration with Dr. Sarah Lambart, University of Utah, USA.

This project follows up on the ERC starting grant project ReVolusions that studied melt inclusion compositions to quantify geochemical cycling at subduction zones.

Your duties

• Separate olivine from lava samples
• Melt inclusion characterisation and homogenisation
• Geochemical analyses by SEM, EMPA, LA-ICPMS
• Clean laboratory sample purification by column chromatography
• Sr-Nd-Pb isotope analyses by TIMS
• Develop- and apply polybaric melt models
• Present results at conferences and in 4 peer-reviewed publications
• Contribute to our teaching programme
• Play a role in supervising MSc and BSc students
• Finalize your work into a PhD thesis

• MSc degree in Earth sciences with a focus on petrology or geochemistry
• Proven hands-on laboratory and analytical experience
• Creative attitude
• Strong scientific motivation
• Good social skills and excellent ability to communicate in spoken and written English

Fixed-term contract: 1 year.

A challenging position at the VU Earth Science Department. We study our dynamic planet from nano- to planetary scale. We quantify the key cycles and interactions in system Earth over timescales from seconds to millions of years by combining fieldwork, lab work and computer simulations. By bringing to bear our fundamental understanding of system Earth and our fresh curiosity we conduct research that is relevant for today's societal challenges including sustainability, climate change and natural hazards. The department's research facilities are regarded as outstanding, while the department's international focus fosters national and international collaboration, both contributing to high-quality and high-impact research outcomes.

The Geology and Geochemistry cluster has just kick-started the NWO-funded large infrastructure "The Netherlands state-of-the-art Isotope Geochemistry Laboratory" (NIGEL), which includes a brand-new clean-laboratory and multiple new mass spectrometry instruments (TIMS, MS/MS-MC-ICPMS coupled to Fs-LA, ICPMS, and ICP-OES).

The salary will be in accordance with university regulations for academic personnel and amounts €2,541 (PhD) per month during the first year and increases to €3,247 (PhD) per month during the fourth year, based on a full-time employment. The job profile: is based on the university job ranking system and is vacant for at least 0.8 FTE.
The appointment will initially be for 1 year. After a satisfactory evaluation of the initial appointment, the contract will be extended for a duration of 3 years.

Vrije Universiteit Amsterdam

The ambition of Vrije Universiteit Amsterdam is clear: to contribute to a better world through outstanding education and ground-breaking research. We strive to be a university where personal development and commitment to society play a leading role. A university where people from different disciplines and backgrounds collaborate to achieve innovations and to generate new knowledge. Our teaching and research encompass the entire spectrum of academic endeavor - from the humanities, the social sciences and the natural sciences through to the life sciences and the medical sciences.

Vrije Universiteit Amsterdam is home to more than 30,000 students. We employ over 5,500 individuals. The VU campus is easily accessible and located in the heart of Amsterdam's Zuidas district, a truly inspiring environment for teaching and research.

Diversity
We are an inclusive university community. Diversity is one of our most important values. We believe that engaging in international activities and welcoming students and staff from a wide variety of backgrounds enhances the quality of our education and research. We are always looking for people who can enrich our world with their own unique perspectives and experiences.

The Faculty of Science
The Faculty of Science inspires researchers and students to find sustainable solutions for complex societal issues. From forest fires to big data, from obesity to medicines and from molecules to the moon: our teaching and research programmes cover the full spectrum of the natural sciences. We share knowledge and experience with leading research institutes and industries, both here in the Netherlands and abroad.

Working at the Faculty of Science means working with students, PhD candidates and researchers, all with a clear focus on their field and a broad view of the world. We employ more than 1,250 staff members, and we are home to around 6,000 students.

About the department
The Department of Earth Sciences has approximately 35 permanent staff members organized in twelve research groups. Research in the department is focused on two general areas: Geology & Geochemistry and Earth & Climate. The Department teaches in the Earth Sciences as well as in the Earth Sciences, Economics & Sustainability BSc programs, and in the MSc programs Earth Sciences and Hydrology. The Department's excellence in teaching is underlined by its high scores in annual national student evaluations.
See https://vuweb.vu.nl/en/about-vu/faculties/faculty-of-science/departments/earth-sciences for further information.