Research Interests Plate tectonics, past plate motions and polar wander, driving forces and stress. Active tectonics on Venus and Mars. Our research on Venus utilizes the topographic and radar data returned by the Magellan project. Michael Stefanick and I have focused our investigation on the distribution of coronae and craters. We find that the distribution of Venus coronae and craters are related to chasmata which are thought to be extensional zones.
Coronae are almost twice as dense near chasms as a random set of the same size.
The distribution of craters can indicate locations of tectonic activing on Venus' surface. Craters, to the first order, are randomly the distributed, although when we compare distribution with random sets we note a deficit of about 40-50 craters close to the chasms. Also, the tectonized and embayed craters tend to be near the rift zones and their distribution closely resembles that of the coronae. This suggests that the volcano-tectonic process creating coronae may be the same one destroying craters. Graduate student John DeLaughter and I are using concentric caldera coronae and radial concentric coronae as age end-members in the model of corona formation and evolution.