This guidebook describes the rocks and landforms along the Dempster Highway. The southern terminus of the highway is located near Dawson City in west-central Yukon. A drive along the Dempster Highway takes you from its junction with the South Klondike Highway (Hwy 2), 717 km northeastward to Inuvik, Northwest Territories. On road maps this is Highway 8 in Northwest Territories, and Highway 5 in Yukon. The Dempster Highway traverses diverse geological features and many contrasting landscapes. It passes rocks created hundreds of millions of years ago, mountain ranges with a complex history of continental collision, hints of the energy resources at depth, and evidence of recent glaciations. The guide is an update and expansion of a guide produced for a fieldtrip sponsored by the Canadian Society of Petroleum Geologists. It also incorporates information from a guide by Tarnocai et al. (1993) and observations of the contributors in 2005 and 2006. In this guidebook you will find an introduction to the general bedrock geology, glacial history and mineral resources of the area, followed by a road log, and a glossary explaining geological terms.

This report provides comprehensive documentation of landslide, permafrost subsidence and fluvial erosion-related geohazards for the Yukon portion of the Dempster Highway. It provides Yukon Department of Highways and Public Works – Transportation Engineering Branch a practical geohazard inventory that will help guide planning and mitigate future risk to the highway. It also becomes a valuable reference pertaining to slope stability, permafrost and fluvial processes in northern Yukon. Results from this study identified 54 mass movement geohazards and 102 meander-highway encroachment sites with the potential for future highway impact. Of particular significance, 75% of the mapped mass movement geohazards are influenced by permafrost or degrading permafrost, an important geological attribute considering future temperatures are expected to increase.

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A 250 km long east-west geological and geophysical transect has been constructed at about 66 degrees 40'N latitude, from near the Yukon-Alaska border, across the Eagle Plains and Richardson Mountains Anticlinorium (RMA), to the Interior Platform in northwestern Canada. It includes reprocessed industry seismic reflection profiles, regional gravity data and drill hole information. The north trending RMA is interpreted as a contractional (pop-up) structure, bounded on the east and west by post-Carboniferous, pre- or syn-Cretaceous thrust faults, that is cored by lower Paleozoic and Proterozoic rocks. The location of the pop-up may have been controlled by a pre-existing west-facing crustal scale ramp at the top of the crystalline basement, because horizontal displacement required to accommodate the pop-up, about 33 km, probably occurred above regional detachment(s) which project westward beneath the Eagle Plains. Contractional deformation in the Eagle Plain fold belt is probably the same age.

This five-day geological excursion across the northern Canadian Cordillera of southern Yukon and northern B.C. will lead the participants from the parautochtonous edge of ancestral North America (Laurentia), near Cassiar, BC, through the Intermontane (peri-Laurentian) terranes and the oceanic Cache Creek Terrane (of Tethyan affinity), and end in the exotic Insular terranes (of Arctic affinity) by Kluane Lake, in southwestern Yukon. The trip will examine the internal and external relationships of terranes that were accreted to ancestral North America in Mesozoic time and discuss models of Cordilleran evolution. Although the field trip route offers limited opportunity to examine the mineral wealth of these terranes, metallogenetic highlights will be presented within their regional tectonic context along the way.

for a copy of this paper please contact the Yukon Geological Survey; geology@gov.yk.ca.