PhD Position in Earth Sciences

Utrecht University

Faculty: Faculty of Geosciences
Department: Department of Earth Sciences
Hours per week: 36–40
Application deadline: 1 February 2026
Location: Utrecht University, Utrecht Science Park, Netherlands

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Your Job

The Department of Earth Sciences is seeking a highly motivated PhD candidate with an MSc background in Earth Sciences, Geochemistry, or related fields. The candidate 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. Minerals transported by rivers to the ocean continue to dissolve, acting as an additional CO₂ sink. In marine sediments, silicate alteration can be dominated by mineral dissolution (forward weathering) or 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 setups representing diverse coastal systems (e.g., beach, shelf). Experiments will test the dissolution behavior of the most common reactive rock types globally: volcanics, siliciclastic rocks, and highly weathered minerals such as metal-(hydr)oxides and clays. Reaction pathways will be identified via fluid and solid element analyses as well as non-traditional stable isotopes (Si, K).

This project is part of the ‘SILICYCLE’ grant, awarded to Dr. Sonja Geilert under the Vidi scheme of the Dutch Research Council (NWO). A personalized training program (~20% of your time) will support your career objectives and include coursework, workshops, and teaching assistance in the Bachelor’s and Master’s programs.

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Your Qualities

The ideal candidate will:

• Hold an MSc degree in Earth Sciences, Geochemistry, or a related discipline by the start date (non-Dutch MSc degrees may require approval from the Board for Conferral of Doctoral Degrees)
• Preferably have experience and strong interest in geochemical laboratory experimental work and non-traditional stable isotope systematics
• Possess a geochemical background (e.g., MSc thesis topic) and laboratory experience
• Be motivated to collaborate in a diverse, multidisciplinary research team
• Have strong social, verbal, and communication skills
• Have excellent command of English

Utrecht University welcomes applicants from all backgrounds and encourages diversity in its research community.

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Our Offer

• Position: 1.0 FTE, initial 1-year contract with extension to 4 years upon successful assessment
• Gross monthly salary: €3,059–€3,881 (full-time, salary scale P, CAO NU)
• 8% holiday pay and 8.3% year-end bonus
• Pension scheme, partially paid parental leave, and flexible employment terms per CAO NU
• Access to professional development, cultural activities, sports, and customizable employment conditions

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About Utrecht University

• Mission: Contribute to a better future through leading research and inspiring teaching
• Faculty of Geosciences: 3,400 students, 720 staff; departments include Earth Sciences, Human Geography & Spatial Planning, Physical Geography, and Sustainable Development
• Department of Earth Sciences: over 50 tenured scientists, 110+ PhD students/postdocs, world-class labs (Electron Microscopy Centre, Geolab, Earth Simulation Lab), and High-Performance Computing facilities

Location: Utrecht Science Park, Utrecht – accessible by public transport or bicycle; city features canals, cafes, shops, and cultural activities

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Application Process

Required Documents:

1. Letter of motivation (describe why you wish to pursue this PhD and why in this department)
2. Curriculum vitae, including relevant courses
3. Academic credentials (marksheets and degree statements)
4. Contact information for at least two referees

Reference letters are not required at initial application. Shortlisted candidates will be contacted for referees.

Selection & Timeline:

• Quick selection process after the application deadline: 1 February 2026
• Interviews likely in calendar week 12
• Preferable start: late spring/summer 2026

Additional Notes:

• International candidates requiring a visa/work permit should allow at least four months processing time; assistance provided via the International Service Desk (ISD)
• Housing in/near Utrecht is the applicant’s responsibility; ISD can provide guidance
• Dutch Mobility Portal offers general information on working and living in the Netherlands

Contact for informal inquiries:
Dr. Sonja Geilert – s.geilert@uu.nl

Application: Online only via Utrecht University portal. E-mail applications will not be accepted.

Apply