This map presents results for calculations of the potential for granitoid plutons to produce radiogenic heat. The calculations are performed using U, Th, and K concentrations from whole rock geochemical data compiled from various sources in the Yukon Geological Survey lithogeochemical database. The objective of this exercise was to identify plutons with anomalously high potential for radiogenic heat production to use as a targeting tool for geothermal resource exploration.

Curie point depth (CPD) mapping in Yukon was done using public domain aeromagnetic data from Natural Resources Canada. CPD mapping estimates the depth in the Earth’s crust to the Curie point temperature (~580°C) where magnetization in rocks disappears. When used in combination with other data, such as heat flow, CPD mapping can serve as a regional scale geothermal prospecting tool. In this study, two different CPD methodologies were employed using two different window sizes (200 km and 300 km). Qualitatively, the results were broadly consistent regardless of the method or window size. South-central Yukon exhibits shallow CPD values while northern and southeastern Yukon have deeper CPD values. This suggests that south-central Yukon has higher levels of heat flow in the mid-to-lower crust compared to the rest of the territory. The CPD results are largely consistent with heat flow measurements from the near surface. Specifically, regions with shallow CPD estimates correspond to areas with elevated heat flow measurements. Geologically, the regions with shallow CPD correspond to the Cordillera, while deep CPD areas appear to be co-located with continental platform rocks of Ancestral North America. Comparison with Yukon-specific crustal geotherms derived from other data suggest that the CPD estimates for south-central Yukon are systematically too deep by 2 to 12 km. The discrepancy is likely caused by the need to better understand and account for the fractal distribution of magnetization in the crust in Yukon. The results of this CPD study are valuable in that 95% of Yukon has been demarcated into regions of shallow CPD (higher heat flow) and deep CPD (lower heat flow). These findings should be combined with other data, such as heat generation and sediment thickness estimates, to identify the most prospective regions of elevated subsurface heat in Yukon.

Borehole Lithology Data for Canada provided by Geothermal Group of the Earth Physics Branch, Ottawa

This layer contains data related to thermal conductivity observations at locationsin Canada, obtained by the Canadian Geothermal Data Compilation. The data table includes general information on the location of the borehole or sample, measurement date, rock name and measurements. Information sources are included in the dataset. The SamplingFeatureURI for a particular sample is the cross-referencing link (foreign key) used to associate the observation with web based information on the feature of interest, including pictures, websites and documents. The data is displayed using a blue and yellow crosshatch symbol.

Canada Borehole Temperatures, provided by the Canadian Geothermal Data Compilation

Background: More than 80% of the heat produced in the Earth's crust comes from granitoid rocks. When granitoid rocks form they naturally concentrate radioactive elements such as U, Th, and K, and the radiogenic decay of these elements is an exothermic reaction. The radioactive decay of these elements within a granitoid body may generate local heat anomalies and elevated geothermal gradient at relatively shallow crustal levels. In combination with other local rock properties (e.g, porosity, permeability, thermal conductivity), radiogenic heat has the potential to generate a geothermal resource. The decay of radioactive elements converts mass into radiation energy, which in turn gets converted to heat. While all naturally radioactive isotopes generate some heat, significant heat generation only occurs from the decay of 238 U ,235 U ,232 Th and 40 K. Therefore, potential heat production is governed by the concentrations of U ,Th and K in the rock. In igneous rocks, radiogenic heat production is dependent on the bulk chemistry of the rock and decreases from acidic (e.g. granite) through basic to ultra basic rock types. Therefore, granites with anomalously high concentrations of U ,Th and K are targets for calculating potential radiogenic heat production. Potential radiogenic heat production (A)from plutonic rocks can be calculated using this equation: A (\\u03BCW/m 3 )=10 -5 \\u1D29 (9.52c u +2.56c K +3.48c Th ) where "c" is the concentration of radioactive elements "U" and "Th" in ppm, and "K" in %; and "\\u1D29" is the rock density. Heat production constants of the natural radio-elements U, Th, K are 9.525x10 -5 , 2.561x10 -5 and 3.477x10 -9 W/kg, respectively. Data and Methods: Geochemical data from \~1760 samples of plutonic rocks from Yukon are used to calculate potential heat production. The calculated values for radiogenic heat production (A) are plotted over the mapped distribution of Paleozoic and younger plutonic rocks and major crustal faults are also shown for reference.

Curie point depth (CPD) mapping in Yukon was done using public domain aeromagnetic data from Natural Resources Canada. In this study, two different CPD methodologies were employed using two different window sizes (200 km and 300 km). Qualitatively, the results were broadly consistent regardless of the method or window size. South-central Yukon exhibits shallow CPD values while northern and southeastern Yukon have deeper CPD values. This suggests that south-central Yukon has higher levels of heat flow in the mid-to-lower crust compared to the rest of the territory. The CPD results are largely consistent with heat flow measurements from the near surface. Specifically, regions with shallow CPD estimates correspond to areas with elevated heat flow measurements. Geologically, the regions with shallow CPD correspond to the Cordillera, while deep CPD areas appear to be co-located with continental platform rocks of Ancestral North America. Comparison with Yukon-specific crustal geotherms derived from other data suggest that the CPD estimates for south-central Yukon are systematically too deep by 2 to 12 km. The discrepancy is likely caused by the need to better understand and account for the fractal distribution of magnetization in the crust in Yukon. The results of this CPD study are valuable in that 95% of Yukon has been demarcated into regions of shallow CPD (higher heat flow) and deep CPD (lower heat flow). These findings should be combined with other data, such as heat generation and sediment thickness estimates, to identify the most prospective regions of elevated subsurface heat in Yukon. Contours have been created for the gridded curie point depth at 1 km intervals and are presented along with the grid. Distributed from [GeoYukon](https://mapservices.gov.yk.ca/GeoYukon/) by the [Government of Yukon](https://yukon.ca/) . Discover more digital map data and interactive maps from Yukon's digital map data collection. For more information: [geomatics.help@yukon.ca](mailto:geomatics.help@yukon.ca)

The BORHOLES layer represents the compilation of available data from various boreholes throughout the Yukon and near the Yukon border. This data set includes oil and gas exploration wells, mineral exploration boreholes, water supply wells and environmental monitoring well. The data points include information on the borehole location, purpose, status, depth, temperature data, water flow and chemistry data where available along with references where further detailed information may be available.

The THERMAL SPRINGS layer represents a compilation of available data from thermal springs throughout the Yukon and near the Yukon border. Spring data points include information on the name of the thermal springs, the measured temperature, the water chemistry, geothermometer results and references where more data may be found.

Curie point depth (CPD) mapping in Yukon was done using public domain aeromagnetic data from Natural Resources Canada. In this study, two different CPD methodologies were employed using two different window sizes (200 km and 300 km). Qualitatively, the results were broadly consistent regardless of the method or window size. South-central Yukon exhibits shallow CPD values while northern and southeastern Yukon have deeper CPD values. This suggests that south-central Yukon has higher levels of heat flow in the mid-to-lower crust compared to the rest of the territory. The CPD results are largely consistent with heat flow measurements from the near surface. Specifically, regions with shallow CPD estimates correspond to areas with elevated heat flow measurements. Geologically, the regions with shallow CPD correspond to the Cordillera, while deep CPD areas appear to be co-located with continental platform rocks of Ancestral North America. Comparison with Yukon-specific crustal geotherms derived from other data suggest that the CPD estimates for south-central Yukon are systematically too deep by 2 to 12 km. The discrepancy is likely caused by the need to better understand and account for the fractal distribution of magnetization in the crust in Yukon. The results of this CPD study are valuable in that 95% of Yukon has been demarcated into regions of shallow CPD (higher heat flow) and deep CPD (lower heat flow). These findings should be combined with other data, such as heat generation and sediment thickness estimates, to identify the most prospective regions of elevated subsurface heat in Yukon. Contours have been created for the gridded curie point depth at 1 km intervals and are presented along with the grid. Distributed from [GeoYukon](https://mapservices.gov.yk.ca/GeoYukon/) by the [Government of Yukon](https://yukon.ca/) . Discover more digital map data and interactive maps from Yukon's digital map data collection. For more information: [geomatics.help@yukon.ca](mailto:geomatics.help@yukon.ca)