Romain Tilhac

PhD candidate

Contact Details

Australian Research Council Centre of Excellence for Core to Crust Fluid Systems (CCFS) and GEMOC
Department of Earth and Planetary Sciences
Macquarie University NSW 2109

Phone : 61-(0)2-9850 9676
Fax : 61-(0)2-9850 6904
Mob: 61-(0)4-2088 0804




Geodynamic context of abundant pyroxenites in Cabo Ortegal, Spain

Understanding the evolution of the mantle in subduction-related environments is an issue of a great geodynamic interest. Ultramafic rocks exposed in the Cabo Ortegal Complex, Spain are intruded by abundant pyroxenites, which may have originated in a subduction zone. This project aims to provide a geodynamic scenario for the formation of these pyroxenites, through their geochemical study. Preliminary results have permitted to re-define the structural framework of the locality, and spatially and temporally constrain the different events of fluids and melts percolation in the subduction zone, with promising application for exploration targeting of mineral resources (e.g. platinum and palladium). Future work will be extended to the study of chromitites and will include cosmogenic (Sr, Nd, Hf, Os) and stable (O, Mg) isotope geochemistry.

Mantle harzburgite in Cabo Ortegal, Spain


Suzanne Y. O’Reilly, William L. Griffin, Norman J. Pearson (CCFS/GEMOC); Michel Grégoire, Damien Guillaume, Georges Ceuleneer (GET) As part of a co-tutelle between Macquarie University and Paul Sabatier University, Toulouse, France




Sampling the pyroxenite-dunite association


Research Interests

- Petrology and geochemistry of ultramafic rocks
- Subduction-related mantle
- Fluid/melt/rock interactions
- Structural geology
- Basin fluids and carbonate diagenesis


Tilhac, R., Ceuleneer, G., González-Jiménez, J.M, O’Reilly, S.Y., Griffin, W.L., Girardeau, J., Henry, H., Grégoire, M., 2014. A new recipe for platinum-group element behaviour in supra-subduction zones: constraints from the Cabo Ortegal Complex, Spain. Geology, submitted.

Tilhac, R., O’Reilly, S., Griffin, W.L., Pearson, N.J., Ceuleneer, G., González-Jiménez, J.M., Grégoire, M., 2014. How mantle heterogeneities control supra-subduction metasomatism: constraints from the Cabo Ortegal Complex, Spain. AESC, Geological Society of Australia, Abstracts, 110, AESC, 22nd Australian Geological Convention, 301.

Recumbent fold in the Cretaceous flysch of the Saint-Jean-de-Luz basin, France


Perrin, C., Prestimonaco, L., Servelle, G., Tilhac, R., Maury, M., Cabrol, P. 2014. Aragonite-calcite speleothems: identifying original and diagenetic features. Journal of Sedimentary Research, 84, 245-269.

Tilhac, R., Guillaume, D., Odonne, F., 2013. Fluid circulation and deformational gradient in north-Pyrenean flyschs: example from the Saint-Jean-de-Luz basin (France). Tectonophysics, 608, 832-846.

Perrin, C., Prestimonaco, L., Servelle, G., Tilhac, R., Maury, M., Cabrol, P. 2013, Growth and diagenetic history of aragonite-calcite speleothems, implications for environmental studies. 16th ICS Proceedings, 2, 447-449.

Perrin, C., Prestimonaco, L., Servelle, G., Tilhac, R., Maury, M. and Cabrol, P., 2012. Aragonite-calcite speleothems (Hérault, France): Identifying original and diagenetic features. 29th IAS Meeting of Sedimentology, 40.



I graduated my Master of Earth and Planetary Sciences in 2011 in Paul Sabatier University, Toulouse, France. I got the opportunity to come to CCFS / GEMOC in Macquarie University in early 2013 to start my PhD. From my previous projects, I had experience in structural geology and fluid-rock relationships in sedimentary rocks and wanted to move on a slightly different topic, where I could benefit from my experience on the field and acquire new laboratory techniques. As for my personal background, I grew up in the Pyrenees and I have been caving, hiking and rock climbing for a long time, which certainly explains my choice for Earth sciences.

Some pictures of the Pyrenean mountains and caves, Africa and more…