FIRST-ORDER IMPACT CRATER GEOPHYSICS AND WATER-ROCK INTERACTION ANALYSIS AT TWO LOCATIONS ON MARS

Impact events are geologically pervasive in the Solar System and can generate significant heat; even small-impact cratering events that produce 5- to 10-km-diameter craters could possibly drive hydrothermal systems on Mars. Plausible hydrothermal systems induced by impacts have been mapped across various terrains on Mars. Prior work has shown that a 30 km-diameter crater on Mars can possibly fuel a hydrothermal system in the subsurface for ~67,000 years. Additionally, analysis of analog impact-induced hydrothermal systems on Earth, such as the relatively small ~4 km-diameter crater at Kärdla, Estonia, indicates that it took between ~1500 and 4000 years to cool to below a temperature of 373.15 K. In the geologically recent Amazonian, two craters have been identified as likely hosting hydrothermal systems, supported by spectral detections of phyllosilicates. Here, to a first order, we model the geophysical parameters and then input select parameters into Geochemist Workbench to model at 373.15 K to 573.15 K to simulate hydrothermal activity. The two craters we investigate are the unnamed ~20 km-diameter crater in the Ismenius Lacus quadrangle (Crater ID 05-000375), and the other is the ~62 km-diameter Stokes impact crater in the Cerbrenia quadrangle (Crater ID 07-0000008). We model these craters and compare observations with model parameters and look for key mineralogies: chlorite, Fe-serpentine, (both observed in Ismenius Lacus crater) and Fe/Mg/Al phyllosilicates (observed in Stokes impact crater). We then evaluate these results in context of Martian near-subsurface habitability.