Southern new Caledonia seismicity: structural implications

The seismicity of the southern part of New Caledonia stretches in a stripe pattern across the island, trending parallel to its western margin. The sei smic activity is mainly concentrated in the peridotite domain and terminate s, to the south, with a permanent swarm where the two largest earthquakes ( mag 5.6 and 5.1) recorded in New Caledonia are Located. This stripe of seis mic activity is located at the boundary between two different domains chara cterized by different average elevations and gravity anomalies. The present -day seismicity is interpreted as the reactivation of a suture zone lying b etween the old Caledonian substratum and a domain of oceanic origin linked to the Loyalty Basin, accreted during the Eocene obduction. ( (C) Academie des sciences/Eisevier, Paris.).