Mapping a "Volcano"

MESSENGER Science Team members are busy studying in detail the newly discovered volcanoes on Mercury (see also PIA10942). This figure, recently published in Science magazine, shows a NAC mosaic of the largest volcano currently identified on Mercury and a geologic sketch map of the major features in the surrounding area.
The “irregularly-shaped depressions” are believed to correspond to volcanic vents, and the “margin of the dome-like feature” marks the outer limits of lava flows from the vents that are thought to have covered up the underlying surface of “hummocky plains”.
The unlabeled double line outlines bright material associated with the volcano, believed to be pyroclastic deposits ejected during volcanic eruptions at the vents. A “highly-embayed impact crater” also appears to have had lava flow up to its rim, while a slightly more distant impact crater is “relatively fresh” and unchanged by any lava.
The volcano is located just inside the rim of the Caloris Impact Basin (see also PIA10383), labeled as “Caloris Basin Rim Units” on this map. Maps such as this are aiding scientists as they work to understand the history of volcanism on Mercury.

Date Acquired: January, 14th, 2008
Image Mission Elapsed Time (MET): Mosaic of 108826812 and 108826877
Instrument: Narrow Angle Camera (NAC) of the Mercury Dual Imaging System (MDIS)
Spacecraft Altitude: about 10.500 Km (approx. 6500 miles)