Thermal stresses in planetary elastic lithospheres

The role of thermal stresses in the tectonics of the moon is reexamined in this paper. A model is used that considers a spherical elastic shell overlying a fluid core. It is shown that the thermal stresses generated by temperature changes within the shell usually dominate over the thermal contraction or expansion of the core. During the entire evolution of the moon the cooling of the lithosphere is likely to have dominated the cooling of the interior and the result would be tensional lithospheric thermal stresses. However, during the recent evolution of the moon the change in the near surface thermal stresses is compressional. It is argued that the surface compressional features on Mercury are not due to the thermal contraction of the interior