Some new measurements of heat flow in the Superior Province of the Canadian Shield

Abstract

Borehole heat-flow measurements are reported from six new sites in the Superior Province of the Canadian Shield. Values adjusted for glaciation effects, but not for Holocene climatic variations, range from 42 to 56 mW/m2. When these new values are combined with 21 previously published borehole values the mean is 42 mW/m2 with a standard deviation of 11 mW/m2. The data for a site on the Lac du Bonnet batholith suggest that the batholith has a thin veneer, less than 3 km, of rock of high radiogenic heat production at the surface.