We begun the survey from the E intersection of South America-Antarctic Ridge (SAAR) with Conrad F.Z. to 3W. Other than the planned E-W lines, additional survey time was necessary in order to obtain the full coverage of the high inside corner (minimum depth 600 m). Morphobathymetry and geophysics (magnetometry) revealed the presence of a ridge segment of SAAR changing its direction from N-S to SW-NE (Fig. 3), in good agreement with recent Sandwell's free-air gravity maps. The S portion of ridge axis has a deep axial valley (mean depth 4000 m, 1.5 km width) that becomes wider and deeper at transform fault - ridge axis intersection. The central magnetic anomaly of ridge axis (Chron 1n, 0.78 m.y, [Cande and Kent (1992)] time scale) is 15 km wide, and the resulting half spreading rate is 0.95 cm/yr. The SW-NE segment is 4000 m deep and 5 km wide; its morphotectonic features suggests the presence of shear stresses. Dredging was performed on high inside corner. We occupied 3 stations (2, 5, 4) recovering peridotites, gabbros, gabbro-dolerites, Cpx-Ol-Pl phyric and aphyric basalts covered by Fe-Mn crust, and glacial erratics.