Volcanism on Mercury

An interpretation of theMariner 10 pictures shows that volcanic plains are largely developed on Mercury, and old and young lava covers can be distinguished occupying no less than 15% of the photographed surface of this planet. Ten and a half volcanic features attributable tovolcanic domes are visible on the pictures, the largest of which being situated at the centre ofOdin Planitia and having a diameter of 7 km and a height of about 1.4 km. The domes have been mapped on a geologic-morphologic map of Mercury (Katterfeld, 1975).The study of newly processed photographs of Mercury and of stereopair pictures of its volcanic «maria» has led to the discovery of a huge volcano at the centre of «Martis Mare» with 110 km long diameter and a double top caldera, the diameters of the external and internal crater being 60 and 40 km respectively. The coordinates of this volcano are 21°S and 124°W.