Surface Evolution of Venus

This chapter contains short descriptions of material units and structures observed on the surface of Venus as well as an abbreviated history of discoveries, that led to the current knowledge of this planet’s geology. It is shown that observed units and structures are broadly similar and commonly exhibit similar age sequences in different regions of the planet, although there is debate as to what degree these sequences can be integrated into any single global stratigraphic model. There is a broad consensus concerning the recent general geodynamic style of Venus (no plate tectonics), on the dominating role of basaltic volcanism in the observed crust-forming processes, and on the significant roles of both compressional and extensional tectonic deformation. Also not under debate is that we see the morphologic record of only the last ~1 b.y. (or less) of the history of this planet and that during this time period the role of exogenic resurfacing was very minor. Several important unresolved questions of Venus geology are formulated and suggestions for future missions, that could lead to resolving them are given.