From the Silurian to the Devonian, the heat flow was smaller, about 58 mW/m2. The heat flow increased gently in Carboniferous and up to 62 mW/m2 in the Permian.

• 志留纪、泥盆纪大地热流较低,约为58mW/m2; 石炭纪大地热流略有增高,二叠纪时大地热流可能达到62mW/m2;