A heat production model of a shield area and its implications for the heat flow ‐ Heat production relationship

The Pikwitonei and Sachigo subprovinces of central Manitoba provide a cross‐sectional view of the Superior Province Crust. To constrain thermal models of the crust, we measured heat production and thermal conductivity in rocks from this terrain using standard gamma‐ray spectrometry and divided bar techniques. These data, when used in a two‐dimensional model of shield crust, show that estimates of surface heat flow and surface heat production yield the well‐known linear relationship between surface heat production and surface heat flow observed for heat flow provinces. This demonstrates that determinations of heat production with depth based on inversion of the linear heat production‐heat flow relationship are non‐unique.