The Shona seamount region, located roughly at 54:32'S, 5:50'W SMALL1995, DOUGLASS1995 was mapped and sampled during our 1996 cruise (Fig. 6). The investigated area shows two distinct volcanic seamounts. The main seamount is a circular, flat-topped volcano, 9 km in diameter at the base, that reaches 925 m b.s.l. It is flanked to the east by two small adventive cones (less than 1 km in diameter) that reach about 1500 m b.s.l. Altered aphyric and fresh vesicular phyric basalts, dolerites and basaltic breccias have been dredged on the southeastern flank. The second seamount, 1650 m deep, is located SE of the main one. Its summit has two craters, less than 1 km in diameter and 100 m deep. This southern volcanic structure is bordered by a NW-SE trending steep scarp where rocks similar to those sampled on the main seamount have been dredged.
We performed two heat flow measurements near the Shona seamount. The first (HF01) is located south-west of the main cone (Fig. 5). The second one (HF-02) is located north east of the seamount, and the gravity core recovered diatomitic layers interbedded with volcanoclastic levels and is showed in Fig. 6.