Thermal conductivity of Caledonian rocks in Scotland and Northern Ireland – Review of Existing Data

Existing documwented sources of thermal conductivity and heat capacity data have been compiled and analysed for the Caledonian rocks of Scotland and Northern Ireland. Methodologies for much of the historic thermal conductivity data are poorly documented. Data from Northern Ireland are sparse. Scottish Caledonian granites typically exhibit interquartile ranges of thermal conductivity between 3 to 3.6 W/m/K. Moinian and Dalradian metamorphic rocks exhibit significant anisotropy in thermal conductivity, with typical interquartile ranges from around 3 to just over 4 W/m/K with the higher values being typical of psammite and quartzites. No clear relationship between thermal conductivity and metamorphic grade was observed in Dalradian metapelites. Thermal conductivities of Devonian Old Red Sandstone from the Midland Valley of Scotland typically exhibit interquartile ranges from 3 to greater than 4 W/m/K, while those of Caithness Flagstones are lower (2.1 to 3.4 W/m/K). Only two documented values of volumetric heat capacity have been located: these measurements (2.26 and 2.14 MJ/m 3 /K) date from the 1880s, and represent Scottish Dalradian metasediments.