Coronal Resurfacing on Venus

One of the major research questions on Venus is the manner in which it resurfaces itself, with a random distribution of a relatively few, large craters providing the only age constraints for the planet's surface. Alongside rift zones, some coronae (large, ovoid tectonic features unique to Venus) are potentially geologically young. Analysis of the population density of small volcanoes associated with coronae demonstrates that coronae and small volcanoes are separated at a regional scale. In addition, stratigraphic analysis of the relative age of volcanoes near coronae suggests that pre-coronal volcanic cones are being destroyed without being replaced by later volcanic cones. When taken into consideration with observations of coronal lava flows preserved in the process of destroying clusters of volcanoes near coronae, this suggests that coronae are potentially an important resurfacing mechanism on Venus even beyond their own annuli. This model of coronal resurfacing is consistent with patchwork resurfacing that may produce the random distribution of large craters on Venus.