The Dynamic History of the Tharsis Region, Mars: Understanding the Magmato-Tectonic Deformation through Structural Analysis and Numerical Modelling

The iconic red planet of Mars boasts an ancient surface which shows evidence of billions of years of volcanism, tectonism, and erosion. However, despite the last few decades’ exponential increase in satellite and rover data from Mars, the sources and timing of the complex surface structures are poorly constrained. One such structurally complex area is the Tharsis Volcanic Province, which is host to the largest volcanoes in the Solar System, and their associated structures. Understanding the structural history of Tharsis holds the key to defining the evolution of the volcanic, and thus planetary and climate, processes on Mars.
To improve this understanding, I investigate two representative study areas in Tharsis: Ulysses Fossae and Ceraunius Fossae. I examine this topic using two different approaches: a comprehensive structural mapping approach, and a numerical modelling approach. Using detailed structural mapping I characterized the extensional features of the study areas, as well as their timing and origins. I found that the structures mapped in Tharsis are younger than previously estimated, and that the deformation is largely driven by diking related to local volcanic and magmatic centres. I further investigate the diking-driven surface deformation process by constructing a Discrete Element 2D numerical model of a dike intruding the Martian lithosphere and find that for material with a sufficiently high Young’s modulus, diking remains a conceivable origin for the extensive graben systems found on Mars’ surface. Together these results paint the picture of a magmatically and structurally active Tharsis during the Amazonian, suggesting that our neighbouring red planet has not been as dormant during the later stages of its geological life, as previously assumed.