Magmatic-volcanic clusters and subclusters in Venus: Tectonic implications

The Surface of Venus is covered with thousands of small (< 20 km in diameter) and large volcanoes (> 100 km in diameter) as well as other structures of magmatic or tectonic origin. Based on a recent catalogue of volcanic centers of Venus, the spatial distribution of volcanic edifices is examined, as well as their relationship with magmatic and tectonic structures. The results indicate that the areas of volcano concentration tend to be formed away from the zones of rifting. In addition, it is found that the zones of rifting are more closely related with places of relatively thicker crust. Based on the observed spatial relationships, a geodynamic model is proposed in which a hierarchy of mantle diapirs is responsible for the deformation of the upper layer of the planet, as well as for the occurrence of volcanism and other structures. Differences in the timing of arrival of those diapirs to the near-surface environment, as well as on the size of individual diapirs, create the various conditions required to produce the wide diversity of all the structures observed at the surface. Thus, instead of adopting a unique evolutionary path that is observed at different stages to explain the diversity of some features, as it has been done until now, a more integral time-dependent model is proposed here having the ability to explain the diversity of expressions of independent features, as well as the relationship between different types of volcano-magmatictectonic features in an integral form.