Territory-wide mineral potential mapping in Yukon was last conducted 18 years ago. An updated suite of maps for land use planning is, therefore, necessary. The YGS has developed a new GIS-based mapping process for this purpose. Industry-based applications using the new method will be developed going forward. The approach makes use of mineral system components that potentially contribute to metal accumulations in an area. The method is a hybrid between a classic data-driven probabilistic approach and an expert-driven fuzzy logic approach. It is non-specific in terms of commodity and/or deposit type – however, the claim and assessment report footprint data that are integral to the mapping process capture these important components. The procedure makes use of block modeling techniques where each block is assigned a prospectivity and (bedrock mapping) confidence score. Calculations are based on the presence or absence of categorical features within unit cells, and the scores represent the posterior favourability of each cell. Evidential layers are weighted according to buffer distance and/or through the application of knowledge-based factors. Lithology classes are factored using a multiclass weights-of-evidence approach. Mineral potential and confidence scores are converted to either a 1, 2 or 3 according to a defined mathematical schema. The values are then combined – blocks with scores of 1:1 have the lowest mineral potential/lowest confidence whereas blocks with scores of 3:3 have the highest mineral potential/highest confidence. Nine possible combinations exist. Mineral potential maps containing measures of both potential and confidence are generated based on the cumulative contrast values. Areas cut by major structures along which significant displacement has occurred need to be evaluated separately, and then stitched back together at the end of the assessment process. Concurrently, the mineral potential data need to be leveled to account for prospectivity differences across the structure concerned.

Contains PDF maps of regional mineral potential by deposit models for Yukon. Also included is a PDF document containing methodology, limitations, and a description of the data used for the assessments. There are three directories: Report folder - open file report in WORD format and PDF format. Index folder- PDF map showing tract numbers; and PDF table of deposit models assessed in each tract. Maps folder - 18 PDF maps of regional mineral potential by individual deposit model.

This paper serves as an update to an earlier paper published by the Yukon Geological Survey: New mineral potential mapping methodology for Yukon: case studies from the Beaver River and Dawson regional land use planning areas (Bullen, 2020). Since the release of the earlier paper, a number of the methods have been modified, and new techniques introduced. These are incorporated into this update paper — the reader is referred to the earlier paper for details of the method itself. Mineral potential maps have thus far been completed for the Beaver River watershed, and the Dawson, Teslin, Na-Cho Nyäk Dun, and Ross River regions. There have been significant updates made to the mineral potential mapping method: 1. Modifications to buffer distance and factors (these are an important fuzzy logic (i.e., non-Boolean) component of the mineral potential mapping process) to enhance mapping outcomes. 2. The introduction of an in-house generated, machine learning algorithm (unsupervised, clustering-type) to classify mineral potential in order to remove the potential for human bias. The method replaces the statistical, areas-under-the-curve approach used previously. 3. A new method for delineating anomalous stream sediment data based on the lithological makeup of each watershed basin. The method computes and compares expected assay values to actual assay values, with values exceeding a certain threshold taken as anomalous. The previous method did not take lithology into account, relying on simple percentile methods only, and was considered insufficiently robust. 4. A new method for categorizing mineral potential confidence. Mineral potential maps produced by the Geological Survey contain measures of bedrock mapping confidence to facilitate land use planning. The updated method is significantly more robust than that used previously. 5. Revisions to the map legend to account for the new, machine learning-based mineral potential categorization methodology. 6. Revisions to the map colour scheme to make them colour blind-safe.

The placer potential mapping process consisted of applying a classification rating of 1 to 5 (lowest to highest) for all streams within the planning area. Factors affecting a stream's potential included development history and hard rock mining potential (gold deposit potential). Terrain attributes such as potential overburden thichness, water flow, or local topography were not factored into the rating due to lack of knowledges for most unmined drainages.

Mineral potential map (1:30,000 scale) of the city of Whitehorse (NTS 105D/14) which shows mineral occurrences and ranks tracts of land based on potential for occurrences. It includes marginal notes.

The southwestern Yukon Coast Belt mapping project is a joint Yukon Geological Survey/Geological Survey of Canada initiative operated under Natural Resources Canada’s GEM (Geomapping for Energy and Minerals) program. This project is aimed at investigating the geological relationships and mineral potential of the Kluane Schist, the Ruby Range batholith and the Yukon-Tanana terrane in southwestern Yukon. Bedrock mapping at 1:50 000-scale followed a 400 m line-spaced aeromagnetic survey flown in the winter of 2010. Preliminary results indicate the presence of a northeast-dipping structural stack through an ~40 km-thick crustal section, whereby the Kluane Schist occupies the lowest structural level and the Yukon-Tanana terrane the highest. The Ruby Range batholith intruded along the contact between the Kluane Schist and the Yukon-Tanana terrane, and was emplaced late in the deformation history. An orthogneiss/paragneiss unit of unknown tectonic affinity was mapped structurally between the Ruby Range and the Kluane Schist. Detrital zircon analyses from two samples of Kluane Schist indicate that the onset of deposition for this metasedimentary sequence occurred after ca. 94 Ma. Two significant metamorphic events, dated at 82 and 70 Ma, affected the Kluane Schist. This indicates that original structural juxtaposition between the Kluane Schist and the Yukon-Tanana terrane pre-dated intrusion of the Ruby Range batholith. Mineral potential in the Coast Belt area is significant and includes porphyry Cu-Mo-Au, epithermal Au-Ag and orogenic Au occurrences. The upper level of the Ruby Range batholith is most prospective for porphyry and epithermal mineralization, while the Kluane Schist is most prospective for orogenic Au mineralization.

not_specified

not_specified

As part of the Canadian government’s commitment to establishing clean energy in the North, the Yukon Geological Survey is collecting subsurface temperature data near communities in the southern part of the territory. The research is a collaborative effort among federal and territorial geoscientists, universities, First Nation governments, and geothermal consultants. A major goal of the project is to determine whether ground temperatures warrant further geothermal exploration in the territory. The study also presents an opportunity for Yukon Geological Survey to educate the public about geothermal energy. This paper summarizes the methods and results of the drilling of two ~500 m geothermal temperature gradient wells. The first was drilled in the fall of 2017 in the Whitehorse area, near Takhini Hot Springs, where a surface water seep measures 46°C. The second well was drilled in winter 2018 in the Tintina fault system, near Ross River. Results to date suggest warm fluids and possible permeable rocks in the Takhini well between 450 and 500 m from surface, and a higher than average geothermal gradient of ~31°C/km in the Tintina Trench near Ross River. The results do not indicate temperatures for power generation at economic depths, however, they are encouraging enough to warrant further geothermal studies in southern Yukon.