Abstract: Remote predictive community-scale surficial geology mapping was completed for the greater Whitehorse area, through desktop interpretation of recent high-resolution imagery (primarily 2013–2019 lidar (Light Detection and Ranging) and 2007 air photos), and supported by field investigations carried out during the 2017–2021 field seasons. The nominal scale of mapping is 1:15 000, although some features were mapped at scales as large as 1:5000. This report provides background on the mapping methodology and classification system used, as well as some discussion of geohazards. The surficial geology is provided as a series of ten 1:15 000 scale map sheets in PDF format (Sheets 1 to 10; Fig. 1), and digitally in Esri geodatabase format (with standardized symbology files), as an accompaniment to this open file report. The map was also used to develop an aggregate potential model (Sheet 11), which can be used to help guide future exploration for gravel resources in the study area.

Geohazards that exist within the study area include landslides, radon gas, seismicity, permafrost and flooding. This report focusses on landslides as the primary geohazard, and includes a robust summary of the unprecedented landslide activity along the Whitehorse escarpment that occurred in early 2022. Recent and historical landslide features are also identified in the accompanying surficial geology map.

Landforms that indicate the presence of permafrost are likewise identified in the surficial geology map. Additionally, Yukon Geological Survey (YGS) collaborated with Yukon University Research Centre (YRC) from 2017 to 2021 to characterize permafrost in the region in detail. The results of this work were recently published by Roy et al. (2021). Their report also provides a summary of historical climate trends and future climate change projections for the Whitehorse area.

Authors: Lipovsky, P.S.

Keywords: aggregate potential, community hazards, flooding, landslides, permafrost, radon, seismicity, community geohazards, Community Hazards

Map Scale: 1 : 15000

NTS Mapsheet(s): 105D09, 105D10, 105D11, 105D13, 105D14, 105E03

Citation: Lipovsky, P.S., 2023. Surficial geology and geohazards of the greater Whitehorse area. Yukon Geological Survey, Open File 2023-1, 67 p. plus appendices

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Report	This PDF is 94 MB.	Download PDF
Report and appendices	This zip file contains the report and appendices, and is 410 MB.	Download ZIP
Appendix 1 - Mapsheets	This zip file is 300 MB.	Download ZIP
Appendix 2 - Spatial data	This zip file is 18 MB.	Download ZIP