Correlation between multichannel seismic data collected over the South Orkney Microcontinent and the ODP Leg 113 well stratigraphy provides the identification and distribution of three main sequences: (1) a syn-rift sequence of ?Eocene/Oligocene terrigenous deposits in the main depocentres up to 2000 m thick. The basin formation and their filling could be related to the rift activity that produced the separation of the South Orkney Microcontinent from Antarctic Peninsula and consequently the development of the Powell Basin; (2) a mainly biosiliceous sequence of middle Miocene to early Pliocene age, present in the basins and on some of the structural highs, deposited after the drifting from Antarctic Peninsula; (3) a diatom-bearing silty and clayey mud of late Pliocene-Quaternary age, draping over the microcontinent. A 3D reconstruction of the acoustic basement and tectonic frame, from compilation of seismic data, highlights the presence of two main structural trends: an east-west trend of the Newton Basin and the east-west elongated structural high in the northern part, and the north-south trend of the main basins along the southern passive margin (Airy, Bouguer, and Eotvos Basins). Furthermore, a new depocentre on the western part has been recognised.