The BOCCA2000 cruise performed from October 6^th to 18^th October 2000 onboard survey vessel TETHYS II of CNRS-INSU was devoted to a seismic survey of the shelf areas between Corsica and Sardinia. Despite almost continous windy and rough sea conditions, about 850km kilometres of reflection profiles of quite good quality have been obtained by using a 1 cu-in GI-Gun and a 6 channel streamer. These new lines complete those obtained during BOCCA99 cruise and allow a rather exhaustive investigation of sedimentary units and structures of the whole shelf down to a few hundreds of metres.

First significant results concern the important tectonism of the Miocene sedimentary units in the Bonifacio basin on the outer part of the western shelf and the presence of  Miocene volcanic reliefs and intrusions at the edge of the shelf that were previously recognised on the slope. These deformations and volcanism more probably represent Northward prolongation of the Miocene events known in the Sardinian rift, although relative and absolute dating still need to be established for the shelf areas.

On the Eastern Corsica-Sardinia shelf, the large Pliocene progradation sequence observed off Southern Corsica during BOCCA99 cruise has been also investigated offshore NE Sardinia. The new data confirms the large seaward growth of the shelf during Pliocene times and the high sedimentation rates during this period. This contrasts with the western shelf where no Pliocene to Quaternary sediments are observed except in the shelf edge - upper slope area.

Moreover, thanks to good seismic penetration, the buried Messinian shelf edge has been located on the Eastern shelf and the connection has been established between the Messinian erosional surface, subcropping or outcropping on the inner shelf , the deeply buried surface below the slope and the thin evaporite  deposits in the Corsican Basin.

The next investigation will mainly concern geological sampling on selected sites in order to ground truth the seismic stratigraphy and the age of the tectonic events.