The volcanology of Idunn Mons, Venus: The complex evolution of a possible active volcano

Abstract

Idunn Mons is a shield volcano located in the Imdr Regio large igneous rise, a Venusian equivalent to a hotspot geologic province on Earth. Recent studies using emissivity data from ESA's Venus Express Mission, together with experimental laboratory studies on the alteration of volcanic materials on Venus conditions, suggest that Idunn Mons is a possible site for very recent or even ongoing volcanic activity. In this work we carried out geologic mapping of Idunn Mons to characterize its materials and structures and to establish its geologic evolution. This study suggests that Idunn Mons is analogous to oceanic island volcanoes on Earth, with volcanic constructive phases that alternate with flank collapse episodes, resulting in its flat-topped summit morphology. These flank collapse events can be related to the intimate temporal and spatial relationship existing between Idunn Mons and Olapa Chasma, a rift that dominates the large igneous rise and relates to the volcano evolution, suggesting that this is not simply a candidate site for active volcanism but also for active tectonism.