Second Order: Thaumasia block

• Megalandslide?

• Brines  salt and ice
• Uplift of Tharsis  volcanic ash and lava flows
• Uplift  radial extension faulting close in
• Uplift  circumferential compression
• Result: gravitational spreading
• Translational movement along Valles Marineris
• Folding at leading edges  Thaumasia Highlands and Coprates Rise
• Montgomery et al. 2009