Eruption history of the Elysium Volcanic Province, Mars

Volcanism has played a significant role in shaping the surface of Mars. Volatiles released during eruptions profoundly altered the composition and density of the Martian atmosphere in the past. Quantifying the amounts of volcanic outgassing has been attempted regionally and globally, however, volume estimates of erupted volcanic material in time are still poorly constrained. Here we show the first eruption frequency record of a volcanic region, the Elysium Volcanic Province, which is the second largest volcanic province on Mars. Studied lava flows show model ages ranging from 3.4 Ga to 60 Ma. Together with observed resurfacing ages, the 'visible' record of volcanic activity extends back to 3.9 Ga. Based on our 190 model ages, continuous volcanic activity is apparent with a major peak at 2.2 Ga. In the last 1 Gyr, the activity rapidly waned. Although the majority of volcanic material (including volatiles released to the atmosphere) erupted within a short time span of less than 200 Ma, activity continued until the very recent past. Extrapolating the eruption record, it appears likely that this region of Mars is still volcanically active today. Our derivation of the eruption record has profound implications for global thermal and atmospheric modeling, indicating sustained heat production, melt generation, and magma ascent at a single location over most of the planet's geological history. (C) 2011 Elsevier B.V. All rights reserved.