In a recent paper, Ingham, Bingham & Cough (1983) report a geomagnetic induction anomaly which is coincident with a geothermal gradient anomaly discovered by Lam, Jones & Lambert (1982) in the Hinton-Edson region of Alberta, Canada. The position of the threecomponent magnetometer array was over a geothermal gradient anomaly whose axis, according to Lam et al. (1982) strikes in a NE-SW direction. lngham et af. (1983) find that their measurements are consistent with an electrical conductivity anomaly whose top is perhaps 10 km deep and which extends to great depth. They suggest that the correlation between the geomagnetic induction anomaly and the geothermal gradient anomaly supports the inference that both are due to the presence of partial melt in the crust. This interpretation is alternative to the suggestion given by Lam er a/. (1982) that the thermal anomaly may be the result of the migration of heated water from west of the Miette region along the south-westward dipping fault planes at great depths of 3-4 km. The area of elevated geothermal gradient between Hinton and Edson was found by Lam el a/. (1982) on the basis of a study of bottom-hole temperatures (BHTs) from exploration well logs. The average geothermal gradient values were determined from the slope of the least squares fitted straight line from each temperature-depth plot in 3 x 3 township/range areas and assigned to the centre of that area. Each area is equal to 28.8 x 28.8 km2 (the Dominion Land Survey system used in Alberta). The temperature depth plots were constructed from BHT data which came from large depth intervals characterized by the sedimentary rocks of different thermal conductivities and under different hydrodynamic conditions. Most probably this is why the standard error of estimate of a theoretical regression of temperature against depth is large and equals 10°C in the study area. Also, in most cases the average geothermal gradients in the study area were determined on the basis of BHT values from depths greater than 1 km. Although Lam et a/. (1982) treated the Hinton-Edson thermal gradient high as a local anomaly, from Fig. 1 it can be seen that it is part of a much larger high geothermal heat flow zone which strikes NW-SE, east of the eastern limit of the Disturbed Belt. A recent broad regional heat flow study of southern and central Alberta by Majorowicz, Jones & Lam (1984) shows that the NW-SE direction of the axis of the elevated heat flow