Plumes and Mantle Dynamics

GéoSciences Réunion aims at understanding the mantle dynamics associated with mantle plumes and subduction zones through geophysical and geochemical investigations.

Our current targets are the southern Pacific ocean (the Society and Marquesas hot spots), the south-western Indian ocean (La Réunion hot spot) and the Euro-Mediterranean domain.

Mantle cross sections combining regional and global tomography in the southern Pacific ocean. The regional tomography including data from the PLUME (2001-2005) and BBOBS projects  highlights the slow mantle anomaly 400 km below the Society hot spot. The global tomography (Fukao et al., 2003) reveals a deep, slow mantle anomaly that culminates at -1000 km, i.e. far below the the 660 km interface previously considered as the upper limit of the "super-plume" in the lower mantle.

Tanaka et al. (2009)


Our recent isotopic compositions reveal that the hot spot of La Réunion is not chemically homogeneous as previously considered but is characterized by two distinct chemical reservoirs.

Smietana et al. (2010)


a- Map of the Bouguer gravity anomaly with the mean splitting parameters plotted at each station. The mean values (listed Table 1) are calculated from the good quality measurements shown in Fig. 3 (listed in supplementary Table S2).

b- Map of mean SKS wave splitting at the stations determined in this study, together with the P-wave tomographic model. Integrating slices between 100 and 200 km depth (Piromallo and Morelli, 2003), the model shows the fast velocity body beneath the Po plain.

Barruol et al. (2011)


 Staff involved: Patrick Bachèlery, Guilhem Barruol, Fabrice Fontaine, Laurent Michon, Magali Smietana.