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New Insights Into The Outlet Conditions Of Late Pleistocene Lake Bonneville, Southeastern Idaho, Usa, Susanne U. Janecke, Robert Q. Oaks Jr.

Susanne U. Janecke

Geologic, geomorphic, and geophysical analyses of landforms, sediments, and structures in northern Cache Valley, USA, document a revised history of flooding and recession of Lake Bonneville, the world's premier pluvial lake. Crosscutting relationships suggest that the Riverdale fault produced a surface-rupturing earthquake ∼25 km southeast of Zenda shortly before, during, or after the Bonneville flood, as well as possible younger surface ruptures. Thus fluctuating stresses and pore pressure induced by changing lake levels may have triggered a large earthquake that, in turn, triggered the Bonneville flood. The flood scoured ∼25 km of Cache and Marsh Valleys and activated landslides during …