YUKON EXPLORATION AND GEOLOGY 2009 1 Preliminary description and slope stability analyses of the 2008 Little Salmon Lake and 2007 Mt. Steele landslides, Yukon M.-A. Brideau and D. Stead Preliminary description and slope stability analyses of the 2008 Little Salmon Lake and 2007 Mt. Steele landslides, Yukon Marc-André Brideau 1 and Doug Stead Earth Science Department, Simon Fraser University, Burnaby, BC Panya Lipovsky Yukon Geological Survey, Whitehorse, YT Michel Jaboyedoff Université de Lausanne, Lausanne, Switzerland Christopher Hopkinson Nova Scotia Community College, Annapolis Valley Campus, NS Michael Demuth Geological Survey of Canada, Ottawa, ON John Barlow Durham University, Durham, Great Britain Steve Evans and Keith Delaney Department of Earth and Environmental Sciences, University of Waterloo, Waterloo, ON Brideau, M.-A., Stead, D., Lipovsky, P., Jaboyedoff, M., Hopkinson, C., Demuth, M., Barlow, J., Evans, S. and Delaney, K., 2010. Preliminary description and slope stability analyses of the 2008 Little Salmon Lake and 2007 Mt. Steele landslides, Yukon. In: Yukon Exploration and Geology 2009, K.E. MacFarlane, L.H. Weston and L.R. Blackburn (eds.), Yukon Geological Survey, p. ?????. ABSTRACT In August 2008, reactivation of the Little Salmon Lake landslide occurred. During this event, hundreds of conical mounds of variable size and composition formed in the deposition zone. The characteristics of these landforms are described and a potential mechanism for their formation is proposed. A preliminary slope stability analysis of the 2007 Mount Steele rock and ice avalanche was also undertaken. The orientation of very high persistence (>20 m long) structural planes (e.g. faults, joints and bedding) within bedrock in the source zone was obtained using an airborne-LiDAR digital elevation model and the software COLTOP-3D. Using these discontinuity orientation measurements, kinematic, surface wedge and simple three-dimensional distinct element slope stability analyses were performed. 1 mbrideau@sfu.ca