• Now post-doctoral researcher at Observatoire de Paris, working with Jacques Laskar; Institut de Mecanique Céleste et de Calcul des Ephemerides CNRS UMR 8028 - Observatoire de Paris/PSL - Sorbonne Université - Université de Lille 77, avenue Denfert Rochereau, 75014 PARIS
  • 2020-2021, post-doctoral researcher at Durham University, UK, dept. of Earth Sciences
  • Joint PhD VUB-UGhent, 2020

PhD Project title:

Astronomical Cycle Identification - New methodological approaches and application to high-resolution Ordovician stratigraphy

Project summary:

The Late Ordovician offers the potential to study extreme climatic conditions, rapid transitions from warm to cold climate (and back), and the functioning of a climate system without the CO2 sink effect provided by continental vegetation. When different techniques for time-series analysis are applied to available geochemical and geophysical data-series, we should be able to identify these climate cycles in the rock record. This project also involves the application of an advanced climate GCM model (HadCM3) to the boundary conditions of this specific period in the Earth's history. This methodology envisages a better insight into the timing and duration of the Ordovician-Silurian climatic events. A data-model comparison will shed light on the role of astronomically driven variations in the climatology of this period.

In order to be able to carry out conclusive astronomical analyses, we ideally need long, continuous and undisturbed sections, which can be challenging, especially for the Hirnantian (e.g. Ghienne et al., 2014). For these sections we need high resolution data in the stratigraphic domain, such as magnetic susceptibility, stable isotopes, lithological variations, CaCO3-content, color reflectance… (ideally, more than one proxy for the same section). The resolution of the data determines the possible periodicities we can identify.

Field sites:

Sedimentary samples from Italy, France, USA, Canada, Morocco, South-Africa,…


IRMS, EA, pXRF, micro-XRF, ICP-MS, Magnetic susceptibility


Philippe Claeys



Cyclostratigraphy Intercomparison Project

Cyclostratigraphy Intercomparison Project, Workshop 2018