Fig. 2

Generalized stratigraphy found within buried preglacial valleys in the Peace River lowlands (right; modified after Morgan et al. 2012), and (left) average valley slopes of the lower Clear River (to the Eureka River) and the Eureka River (blue), and the lower Saddle River (to the Spirit River) and the Spirit River (red). Five of the landslides described appear be associated with ice-advance -phase glaciolacustrine sediment (LTA3), and two with the lower portion of the glacial sediments (LTA4). The valley slopes appear to reflect the stratigraphy. The slopes are lowest where the rivers are incising through LTA3 or LTA5, and steepen where the river incises into LTA4. Note that thickness of LTA4 has been exaggerated in this diagram, as the diamict is not topography constrained and will impact the valley slope response to incision over a longer distance than the unit thickness would otherwise suggest