This study presents the first shale gas appraisal of Devonian-Mississippian shale strata in Yukon’s Liard basin. Assessed volumes of 68 Tcf gas-in-place and 7.6 Tcf marketable gas are contained within two shale plays identified from an integrated wireline log and geochemical evaluation: the Devonian (Givetian-Frasnian) Horn River shale and the Devonian-Mississippian (Famennian-Tournaisian) Exshaw-Patry shale. Average burial depths of 3018 mTVD and net pay thicknesses of 73 m for the Horn River, and 2688 mTVD and 89 m for the Exshaw-Patry plays are interpreted. Both plays are dominated by black, organic-rich, siliceous mudstones, and exhibit: elevated TOC contents (0.6-6.9 wt %); maturities within or past the dry gas window (2.1-4.6 %Ro); very high biogenic silica proportions (averaging 80.2-90.3%); high mineralogical stiffness (0.80-0.87); and average porosities of 1.2% for the Horn River and 4.2% for the Exshaw-Patry play. Resource distribution models indicate 50% of Yukon’s marketable gas will be found in 30% of its assessed area, with the best potential for significant volumes located in the very southeast of the territory where play depth and thickness increases.

Ikon Science Canada conducted a preliminary scoping study of shale gas play data from Yukon’s portion of Liard Basin to determine any potential for future assessment of pore pressure variability in the basin to be undertaken or contracted out by YGS at a later date. The study was a desk-top synthesis of existing, publicly-available geological and petrophysical data; no new data were collected as part of this project.

Summer 2017 fieldwork in Yukon’s lower Paleozoic shale basins (Selwyn basin and Richardson trough) involved participants from government geological surveys (Yukon Geological Survey, Geological Survey of Canada) and several universities (Queen’s, McGill, St. Francis Xavier, Stanford and Dartmouth College). Research interests include: 1) shale chemostratigraphy and biostratigraphy, and pyrite trace element geochemistry to characterize shale units and assess lower Paleozoic paleoenvironmental conditions and depositional controls; and 2) an assessment of hyper-enriched black shales, specifically the colloquial ‘Nick’ or ‘Ni-Mo’ mineralized Ni-Zn-Mo-PGE deposit, in order to develop internally consistent genetic and exploration models for these types of deposits. This paper describes individual research projects underway and summarizes fieldwork in summer 2017.

Previous studies based on regional geology, sediment type and stratigraphic thickness, concluded that the Bonnet Plume Basin in northeastern Yukon has gas potential, but insignificant oil potential. However, these studies were not based on samples collected from within the basin. For this study, in total, 226 rock samples collected from outcrop and drill core throughout the Bonnet Plume Basin were analyzed by Rock-Eval 6 programmed pyrolysis and combustion to assess the petroleum source-rock potential of the strata. The results indicate that the Road River Formation (Cambrian to Devonian) has no source rock potential, but the Bonnet Plume Formation (Cretaceous to Tertiary) has gas and perhaps oil potential. Potential oil generation in the Bonnet Plume Formation is attributed to the occurrence of liptinite-bearing coal and previously unrecognized, siliceous, oil shale. A hydrocarbon-rich tar associated with a naturally burning coal seam was also discovered in the Bonnet Plume Formation.

YEG 2010 contains up-to-date information on mining and mineral exploration activity, studies by industry, and results of recent geological field studies. Information in this volume comes from prospectors, exploration and government geologists, mining companies and students who are willing to contribute to public geoscience for the benefit of the scientific community, general public, and mineral and petroleum industries of Yukon.

YEG 2009 contains up-to-date information on mining and mineral exploration activity, studies by industry, and results of recent geological field studies. Information in this volume comes from prospectors, exploration and government geologists, mining companies and students who are willing to contribute to public geoscience for the benefit of the scientific community, general public, and mineral and petroleum industries of Yukon.

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This report is a synthesis of the Yukon Geological Survey’s placer fieldwork and captures information collected from approximately 120 site visits conducted each season. Information is supplemented by details from staff at Compliance Monitoring and Inspections and, from conversations throughout the off-season with miners. This edition of the placer industry report is larger than ever, which speaks to the level of activity in the various districts and our commitment to providing an accurate record. In order to provide practical information, we have continued to increase the amount of geological detail in the report. The scope of the report also aims to capture mining activity and equipment utilized at each site. This helps frame the style of mining and gives a general idea about mine layout and processing techniques. The overall aim of the property descriptions is to provide a reference that is both insightful in the short term and informative decades into the future.