Utrecht University is inviting applications for a fully funded PhD position in the Department of Earth Sciences, focusing on the impact of terrigenous mineral input on marine silicate alteration and element cycles. This research is part of the Vidi grant project 'SILICYCLE,' led by Dr. Sonja Geilert and funded by the Dutch Research Council (NWO-I). The project aims to experimentally assess mineral reaction rates in various coastal environments, simulating the diversity of beach and shelf systems where silicate alteration occurs. The successful candidate will investigate mineral dissolution and precipitation rates using a range of experimental setups, focusing on globally common reactive rock types such as volcanics, siliciclastic rocks, and highly weathered minerals (e.g., metal-(hydr)oxides and clays). The research will employ fluid and solid element analyses as well as non-traditional stable isotope (Si, K) analyses to identify reaction pathways. The project addresses key questions in geochemistry, Earth sciences, and environmental science, particularly regarding the role of rock weathering and mineral transport in Earth's climate and marine element cycles. The PhD position is for four years, with an initial one-year contract and extension upon successful assessment. The gross monthly salary ranges from €3,059 to €3,881 (full-time), plus 8% holiday pay and 8.3% year-end bonus. Utrecht University offers a comprehensive benefits package, including a pension scheme, partially paid parental leave, professional development opportunities, and flexible employment terms under the Dutch Collective Labour Agreement for Universities (CAO NU). The university also provides access to world-class laboratories and high-performance computing facilities. Applicants must have completed an MSc degree in Earth Sciences, Geochemistry, or a related discipline by the start of the position. Preferred qualifications include experience in geochemical laboratory experimental work, non-traditional stable isotope systematics, and general laboratory work. Candidates should be motivated, team-oriented, and possess strong communication skills. Proficiency in spoken and written English is required. The department values diversity and encourages applicants from all backgrounds. To apply, candidates must submit an online application via the Utrecht University portal, including a motivation letter, CV, academic credentials, and contact details for at least two referees. The application deadline is 1 February 2026. For informal inquiries, contact Dr. Sonja Geilert at [email protected]. The preferred starting date is late spring or summer 2026. International candidates requiring a visa or work permit will receive support from the university's International Service Desk. This opportunity is ideal for candidates interested in geochemistry, marine element cycles, silicate alteration, and experimental geoscience, and offers a supportive, multidisciplinary research environment at one of Europe's leading universities.