We seek a highly motivated postdoctoral candidate to conduct flow-through experiments and chemical analyses at Utrecht University, as well as isotopic analyses in collaboration with Dr. Philip Pogge von Strandmann at Johannes Gutenberg Universität Mainz, Germany. 
Clays are abundant in many of the environments that people interact with and the reactivity of clays plays a crucial role in the chemistry and hydrology of those systems. Clay formation in geothermal systems, for example, can clog pores, and therefore decrease the power-harvesting potential of geothermal power plants. In addition, the slow growth of clays is thought to limit the extent of mineral weathering, which is considered one of the key feedbacks in the global carbon cycle. Despite the importance of clay reactivity, it proves challenging to measure. However, in recent years several studies have demonstrated the possibility of using lithium isotopes as a tracer of clay formation and dissolution, as lighter lithium is preferentially incorporated into clays. Although this tracer is promising, there are several unknowns that have limited its application in the field, so far. The aim of this project, funded through the Nederlandse Organisatie voor Wetenschappelijk Onderzoek (Dutch Research Council), is to resolve these unknowns by probing the interaction of Li with clays, using experiments.

As our postdoctoral Researcher you will use a combination of tools including mass spectrometry for the analysis of Li and its isotopes, as well as 4D (3D space + time) X-ray tomography. Experiments will be carried out at pressure and temperature conditions up to those expected in the Dutch subsurface, particularly for sites that are used and are of interest for geothermal energy. These experiments will yield novel information into the interaction of Li with clays. Thus, the experiments will enable us to test the feasibility of using Li isotopes as tracers of clay reactivity in areas which are difficult to sample directly. In addition, it will allow us to provide critical input, required for models on climate change. The project will focus on research. This may include BSc and MSc student research projects, in which you will be expected to take a leading role.

Applicants should have a PhD degree in Earth Sciences, ideally with a strong background in experimental, low-temperature mineral science and preferentially including the use of stable isotope geochemistry. Established skills in mass spectrometry analysis of isotopes and/or X-ray tomography is preferred. In addition, you should be willing to work on an interdisciplinary project, travel abroad (e.g. to Germany), and to expand your knowledge of analytical techniques. You should be proficient in English and have excellent scientific writing and presenting skills. You are an enthusiastic team player and have good communicational skills.

We offer a temporary position (1.0 FTE) for three years in an international working environment. The gross salary - depending on previous qualifications and experience  - ranges between €3,270 and €3,807 (scale 10.3-10.7 according to the Collective Labour Agreement Dutch Universities) per month for a full-time employment. Salaries are supplemented with a holiday bonus of 8% and a year-end bonus of 8.3% per year. In addition, Utrecht University offers excellent secondary conditions, including an attractive retirement scheme, (partly paid) parental leave and flexible employment conditions (multiple choice model). More information about working at Utrecht University can be found here.

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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.

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