This is a study of the extensional mechanisms in the Woodlark basin where westward propagation of seafloor spreading is accompanied by active continental extension in the D'Entrecasteaux islands and flanking basins immediately landward of the propagator. A suite of deep seismic images will be constructed. The aid of the project is to determine: (1) whether intra-continental extension is occurring along low-angle detachment faults or normal faults, (2) whether seismogenic faults can be correlated with faults observed in the seismic sections, (3) the whole crustal geometry of structures that bound the core complexed of Goodenough and Fergusson islands, and (4) whether the transition from intra-continental extension through to continental breadup reflect an evolution of extensional mechanisms.