PhD student position in bivalve shell geochemistry and microstructures

The Institute of Geosciences (Paleontology group) at the University of Mainz invites applications for a PhD student position (temporary appointment) to study the link between the microstructure and element geochemistry of bivalve shells with the goal to develop new and constrain existing environmental proxies.

Shells of bivalve mollusks offer exceptional potential for high-resolution paleoclimate research. However, extracting specific environmental data such as water temperature from the shells remains a very challenging task owing to the limited number of reliable and well-accepted proxies. In many other organisms, trace and minor elements (TME) provide serviceable environmental proxy data. However, in bivalves their interpretation is notoriously difficult, because the uptake, transport and incorporation of TME into the shells is under strong biological control. These vital effects superimpose themselves on environmental signals. Fortunately, these vital effects seem to be reflected in the shell microstructure. Some microstructure types contain higher levels of certain TME than others. In addition, the architecture of the shell varies strongly at the µm-scale which results in a small-scale chemical heterogeneity. Thus, contemporaneously formed shell portions deviate chemically from each other if their microstructure differs. The successful candidate will test the hypothesis that environmental signals can still be isolated from TME variations through a combined and systematic analysis of shell TME and microstructures. He/she will parameterize the typical TME levels in different microstructures in order to eliminate non-environmental variations from TME. This includes the need to quantify the shape of individual µm-sized microstructural units in SEM images. Together with our Japanese project partners, we will ultimately develop a multidimensional numerical model that combines the TME distribution, microstructure and environmental parameters.

Candidate profile:

  • Master or diploma degree (above average grade) in geosciences, biology or marine sciences (or closely related field)
  • Outstanding motivation and enthusiasm
  • Hands-on experience with LA-ICP-MS and scanning electron microscopy (SEM)
  • Experience with data analysis and statistical methods, and, ideally, pattern recognition and image processing
  • Basic knowledge of paleoclimatology, paleoecology and mollusk biology
  • Previous experience with the analysis/interpretation of growth patterns, chemistry, and/or microstructure of biological hard tissues is advantageous (sclerochronology)
  • Computer literacy, in particular, skillful use of MS office package, graphics software, and programming languages (e.g., Python, C++ etc.)
  • Ability and willingness to conduct laboratory work and image processing (pattern recognition, automated quantification of shape, size, habit etc.)
  • Excellent written and oral communication skills in English
  • Ability to work independently and self-guided, but likewise within an interdisciplinary research team

The appointment will be for a maximum of three years and starts on 1 Sep. 2020 or shortly thereafter. Salary according to TV-L E13 (50% position) includes fringe benefits (health insurance etc.). The University of Mainz is an equal opportunity employer. Disabled persons with comparable qualification receive preferential status.

Interested individuals are invited to submit an application package including a motivation letter explaining why they apply and how they meet the hiring criteria outlined above, CV, copies of certificates (high school, BSc and MSc/diploma), degree transcripts (plus English or German translation) including an explanation of the scoring system, and addresses of at least two referees as a single pdf to Prof. Dr. Bernd R. Schöne,, Institute of Geosciences, University of Mainz, Joh.-J.-Becher-Weg 21, 55128 Mainz, Germany. Application Deadline: 19 August 2020. Note, application review will begin immediately. The position will remain open and applications will be reviewed until the position is filled. Further information about the research foci of the Applied and Analytical Paleontology research team can be obtained at

posted: 30 July 2020     Please mention EARTHWORKS when responding to this advertisement.