The long runout of the Heart Mountain landslide: heating, pressurization, and carbonate decomposition Academic Article uri icon

abstract

  • The Heart Mountain landslide of northwestern Wyoming is the largest subaerial landslide known. This Eocene age slide slidāˆ¼ 50 km along a shallow 2 slope, posing a long-standing enigma regarding its emplacement mechanism. We suggest here a mechanism for the catastrophic emplacement of the Heart Mountain landslide that is independent of slide triggering. The mechanism is a feedback between shear heating, thermal pressurization, and thermal decomposition of carbonates at the slide shear zone. Such a feedback arises when a porous, fluid-filled shear zone heats up because of frictional sliding. If the shear zone is confined, the generated heat leads to pore pressure rise, which in turn reduces frictional resistance to sliding, leading to acceleration. Temperatures at the shear zone quickly reach the decomposition temperature of carbonates. Since the shear zone of the Heart Mountain slide is loc...

publication date

  • October 1, 2010