Utrecht University, Department of Earth Sciences

Utrecht University's Faculty of Geosciences studies the Earth: from the Earth's core to its surface, including man's spatial and material utilisation of the Earth - always with a focus on sustainability and innovation. With 3,400 students (BSc and MSc) and 720 staff, the faculty is a strong and challenging organisation. The Faculty of Geosciences is organised in four Departments: Earth Sciences, Human Geography & Spatial Planning, Physical Geography, and Sustainable Development.

The Department of Earth Sciences conducts teaching and research across the full range of the solid Earth and environmental Earth sciences, with activities in almost all areas of geology, geochemistry, geophysics, biogeology and hydrogeology. The department hosts a highly international tenured staff of over 50 scientists and more than 110 PhD students and postdoctoral researchers. We house or have access to a wide variety of world-class laboratories, among which are UU’s Electron Microscopy Centre, the Geolab, and the Earth Simulation Lab. We also have excellent High- Performance Computing facilities.

About Utrecht

The department and its facilities are located at Utrecht Science Park. Utrecht is the fourth largest city in the Netherlands with a population of nearly 360,000 and forms a hub in the middle of the country. Its historical city centre and its modern central station can easily be reached from the Science Park by public transport or by a 15-minute bicycle ride. Utrecht boasts beautiful canals with extraordinary wharf cellars housing cafés and terraces by the water, as well as a broad variety of shops and boutiques.

Homepage: https://www.uu.nl/geo/aw/

The Department of Earth Sciences is looking for a highly motivated PhD candidate with a MSc background in Earth Sciences, Geochemistry or other appropriate fields. You will work on the project “Impact of terrigenous mineral input on marine silicate alteration and element cycles”.

On geological time scales rock weathering controls Earth’s climate by providing a natural CO₂ sink. In addition to dissolved components, minerals are transported by rivers to the ocean, where they continue to dissolve and act as an additional CO₂ sink. In marine sediments, silicate alteration can be dominated by either mineral dissolution (forward weathering) or by secondary mineral precipitation (reverse weathering). The net marine CO₂ drawdown and element turnover related to marine silicate alteration is not well quantified.

In this 4-year study, you will investigate mineral dissolution and precipitation rates using various experimental set-ups, that represent the diversity of coastal systems (i.e. beach, shelf) in which silicate alteration occurs. In these experiments, you will test the dissolution behavior of the globally most common reactive rock types, that are volcanics, siliciclastic rocks and highly weathered minerals, such as metal-(hydr)oxides and clays. Identification of reaction pathways will be done via fluid and solid element as well as non-traditional stable isotope (Si, K) analyses. This PhD project is part of the ‘SILICYCLE’ grant, awarded to Dr Sonja Geilert under the Vidi scheme of the Dutch Research Council (NWO).

A personalised training programme will be set up, reflecting your training needs and career objectives. About 20% of your time will be dedicated to this training component, which includes following courses/workshops as well as training on the job in assisting in the Bachelor’s and Master’s programmes of the department at Utrecht University.

Qualifications

We welcome a motivated team-player who recognizes themselves in the following description:

You must have completed your MSc degree in Earth Sciences, Geochemistry or a related discipline by the time the position starts. Non-Dutch MSc diploma’s may be subjected to specific approval by the Board for Conferral of Doctoral Degrees before the candidate can be accepted in the PhD programme.

Preferably, you will also have:

• Experience and strong interest in geochemical laboratory experimental work and non-traditional stable isotope systematics;
• A geochemical background (e.g. MSc thesis topic) and general laboratory work experience is of advantage;
• Motivation to cooperate in a diverse and multidisciplinary research team;
• Adequate social/verbal/communication skills.

Due to the international character of our research, good command of spoken and written English is essential. We highly encourage applicants from all members of our community and of diverse backgrounds to join us.

Terms of employment

We offer:

• a position (1.0 FTE) for 1 year, with an extension to a total of four years upon a successful assessment in the first year, and with the specific intent that it results in a doctorate within this period
• a working week of 36 - 40 hours and a gross monthly salary between € 3.059 and €3.881 in the case of full-time employment (salary scale P under the Collective Labour Agreement for Dutch Universities (CAO NU));
• 8% holiday pay and 8.3% year-end bonus;
• a pension scheme, partially paid parental leave and flexible terms of employment based on the CAO NU.

In addition to the terms of employment laid down in the CAO NU, Utrecht University also offers a range of its own schemes for employees. This includes arrangements for professional development, various types of leave, and options for sports and cultural activities. You can also tailor your employment conditions through our Terms of Employment Options Model. In this way, we encourage you to keep investing in your personal and professional development. For more information, please visit Working at Utrecht University.

For informal information (not for application) about this position, please contact Sonja Geilert at s.geilert@uu.nl

To apply, please go to the advertisement on UU's own website and follow the steps there. Include the following information in your application:

• a letter of motivation, in which you describe why you wish to pursue this PhD position and what makes you the best candidate for it; also include why you wish to pursue your PhD in our department in general;
• your curriculum vitae, including any courses taken that are relevant for the position;
• academic credentials (mark sheets and degree statements) as far as already available and relevant.
• (e-mail) contact addresses of at least two referees

No reference letters need to be submitted in your initial application. If you are short-listed, we will contact your referees. We aim for a quick selection procedure after the application deadline of 01.02.2026. The interviews will likely be in calendar week 12 and preferable starting date is late spring/summer 2026.

Note that international candidates that need a visa/work permit for the Netherlands require at least four months processing time after selection and acceptance. This will be arranged with help of the International Service Desk (ISD) of our university. Finding appropriate housing in or near Utrecht is your own responsibility, but the ISD may be able to advise you therewith. In case of general questions about working and living in The Netherlands, please consult the Dutch Mobility Portal.

Online screening may be part of the selection. Commercial response to this ad is not appreciated.