Venus resurfacing by coronae: Implications from impact craters

Abstract

Coronae, common volcano-tectonic features on Venus, may be actively modifying the planet's surface. To evaluate the extent of their effects, we compare impact crater densities and proportions of modified craters out to four radii for Monte Carlo simulations of corona location with those for two corona classes. We study the Radial Concentric and Concentric Caldera coronae, the two classes believed to represent the youthful and senescent stages of formation, respectively. A high proportion of tectonized craters and low crater density near Radial Concentric coronae indicate recent activity. Based on the average crater density and proportion of tectonized craters, we interpret Concentric Caldera coronae as old. These results show that tectonism and volcanism is not limited to the corona interior and can extend up to four radii from the center. Copyright 1997 by the American Geophysical Union.