A Minimally Cemented Shallow Crust Beneath InSight

Ice and other mineral cements in Mars' shallow subsurface affect the mechanical properties of crust, geologic processes that shape planet's surface, search for past or extant Martian life. Cements increase seismic velocities. We use rock physics models to infer cement from Model results confirm upper 300 m Mars beneath InSight is most likely composed sediments fractured basalts. Grains within sediment layers are unlikely be cemented by ice cements. Hence, any existing nodular formed away grain contacts. Fractures basalt could filled with gas, 2% 98% no more than 20% ice. Thus, ice- liquid water-saturated exist InSight. Any at contacts has been broken impacts marsquakes.