Terrestrial Heat Flow in North-east England

Abstract

Heat flow is estimated to be 2·19 μcal cm−2 s−1 at Rookhope, northern Pennines, and 20 km SE it is 2·29 μcal cm−2 s−1 at Woodland. Heat flow at South Hetton in the Durham coalfield has been re-computed from 19th century observations to be 1·38 μcal cm−2 s−1. The northern Pennine values are about twice the value of about 1·16 μcal cm−2 s−1 at Kirkleatham and Tocketts in North Yorkshire. The high heat flow at Rookhope may be explained in part by the high observed radioactivity of the underlying Weardale granite, but even allowing for uniform radioactivity down to 9 km the heat flow contribution from beneath this depth appears to be greater below the northern Pennines than below North Yorkshire. The high heat flow at Woodland, which does not overlie the Weardale granite, is problematical but may be related to rise of hydrothermal water near the Butterknowle fault system.