A broad depression area is located S of the western tip of Bouvet F.Z., whose northern slope is formed by an EW topographic high, with a negative magnetic anomaly centered on the top. The western slope of the depression is characterized by an arcuated relief. Sampling of the two structures (22, 23) recovered slightly altered Cpx-Ol-Pl phyric and aphyric basalts covered by Fe-Mn crust. We also did an Heat Flow station (HF05) at a depth of 3270 m and the associated core recovered sandy clay intercaled with diatomitic sediments.