In collaboration with the Yukon Geological Survey, Teslin Tlingit Council, and other project partners, Innovate Geothermal Ltd. performed an analysis of geoscience data in south-central Yukon as part of an effort to better understand the potential for geothermal energy resources that, if present, could be utilized to help reduce fossil fuel use in Yukon communities. The study area for this project is located near the Village of Teslin and straddles the Teslin fault zone. The main aim of this project is to analyze and interpret a variety of pre-existing and newly acquired geologic and geophysical data sets to evaluate whether geothermal reservoirs may be present within the study area. A secondary aim is to propose favourable drilling locations, if warranted, for exploratory wells to collect information on subsurface temperature and permeability. The geoscience work accomplished here includes both 2D map interpretation as well as construction of a 3D geologic model that was guided by geophysical inversion modelling of gravity and magnetic survey data. In the Teslin study area, the distribution of temperature in the subsurface remains a significant unknown; however, limited evidence suggests subsurface temperatures are modestly above average. Specifically, regional-scale, Curie point depth estimates suggest the geothermal gradient in the area is ~45 °C/km. Drilling is required to measure actual subsurface temperature gradients in the vicinity of Teslin. Furthermore, subsurface permeability does appear possible in the study area. Analysis of
the geoscience data shows evidence for a complex structural environment that appears favourable for subsurface fracture permeability in the Teslin fault zone area. In addition, geologic mapping and geophysical modelling suggests that large portions of the Teslin study area are underlain by quartzite and volcanic bedrock. Both rock types have a favourable potential for maintaining open fractures. Many unknowns regarding the temperature and permeability of the subsurface still exist in the Teslin study area. The location of a 500 m deep scientific research well is proposed to help answer many of the remaining questions.