Topographic evidence for geologically recent near-polar volcanism on Mars

The Mars Orbiter Laser Altimeter (MOLA) was used to measure the topography of several putative near-polar martian volcanic craterforms. We believe the y were formed by effusive lava shield building eruptions and were not hydro magmatic events, as previously suggested. Furthermore, these craterforms ap pear to be geologically recent, with ages between 1 and 20 million years, a nd may provide new evidence of localized thermal anomalies in the upper mar tian crustal column. (C) 2000 Academic Press.