CANADIAN GEOSCIENCE MAP: RIPLEY LANDSLIDE, THOMPSON RIVER VALLEY, BRITISH COLUMBIA, CANADA

The Geological Survey of Canada (GSC) Canadian Geoscience Map (CGM) Series provides fundamental baseline information on bedrock and surficial (solid and drift) geology, geohazards and natural resources. Here, we present a new CGM from south-central British Columbia, along a 10-km reach of Thompson River south of Ashcroft. This section of the valley is historically prone to landslide activity that has repeatedly damaged vital national railway infrastructure, threatened salmon runs, potable water supplies, cultural heritage features and public safety. To better manage geohazard risk in this critical transportation corridor, government agencies, universities, and the railway industry partners are currently directing research efforts, including terrain mapping, on the very slow-moving Ripley Landslide. Mapping activities are focusing on desktop compilation of geographic and temporal datasets (e.g., ground control points, digital surface models, global navigation satellite system stations, interferometric analyses of synthetic radar imagery). Benchmark field observations include lithofacies and landform associations, unit thicknesses, earth material textures, degree of sorting, weathered and un-weathered colours, sedimentary structures and penetrative planar structures, degrees of consolidation, stratigraphic contact relationships, estimated geological age, and other distinguishing characteristics. A digital CGM and database (available free for download through the Natural Resources Canada GEOSCAN website https://geoscan.nrcan.gc.ca/) has applications for a range of end-users, including geotechnical engineers, resource explorationists, ecologists, archeologists, academic geoscientists, land-use planners, risk managers, and the general public.