Onion morphology and microstructure of polyhedral serpentine

Alain Baronnet (1) , Muriel Andréani (2) , O. Grauby (1) , Bertrand Devouard (3) , Serge Nitsche (1) , Damien Chaudanson (1)

1 Université Paul Cézanne - Aix-Marseille 3
2 IPGP - Institut de Physique du Globe de Paris
3 LMV - Laboratoire Magmas et Volcans

We describe the shape and internal structure of polyhedral spheroids found in serpentinized peridotites which correspond to a new serpentine microstructure. Serpentine spheroids resemble geodesic domes made of c. 160 to 180 triangular facets. At facet edges, the nested layers bend by c. 14° along their three <010> crystallographic directions, resulting in an onion-like structure with lateral continuity of the layers. The stacking of the serpentine layers within sectors is controlled by interlayer bonding. These polyhedral onions are made of a novel type of spherical nanostructure for layered materials.

Mots clés: TEM; serpentine minerals; microstructure; onion; spheroid; SEM; TEM.

Domaines: Océan, Atmosphère; Tectonique

Alain Baronnet, Muriel Andréani, O. Grauby, Bertrand Devouard, Serge Nitsche, et al.. Onion morphology and microstructure of polyhedral serpentine. 2007. ⟨hal-00135139⟩