Deep and shallow crustal structure control on the late-stage volcanism in Syria Planum (Mars)

Long-lasting widespread volcanism in Mars is testified by the Tharsis volcanic province, one of the largest volcanic provinces with the largest shield volcanoes of the Solar System. However, volcanism on Mars is characterized also by the occurrence of broad volcanic fields, either in the form of small lava shields or monogenic volcanic cones. The region of Syria Planum (SP) is located east of the Tharsis province and between Noctis Labyrinthus to the North and Claritas Fossae to the southwest. It is an example of diffuse volcanism, presenting hundreds of small edifices (namely Syria Colles) which occur on top of a large bulge roughly 300 km x 200 km in size. SP exhibits a complex magmatic and volcano-tectonic evolution spanning from the early-Noachian to the more recent Amazonian. In this work, we investigate the geometry of the plumbing system of the SP volcanic field as well as the geometries of the volcanic constructs (i.e., vent elongation and vent alignment) that may be linked to the structures that fed the magma presenting a possible tectonic and volcanic evolution of the distributed volcanism phase in this area. The spatial distribution of vents and the overall map view shape of the volcanic field were studied in terms of vent clustering and spatial distribution. We show that the widespread and diffuse volcanism in SP presents clear vent clusters that are related to a deep source magma reservoir located at -100 km depth. We also show that Syria Colles vent elongations and azimuth distributions suggest that the magma exploited the inherited regional structural framework, coherent with the Syria Colles late-stage Amazonian magmatic event, and highlighting the role of a shallow crustal tectonic framework in shaping the Martian volcanism.