Fig. 1

Potential processes and their timescales. Illustration of potential thermal effects on a single fracture under low to moderate temperatures. a Original fracture, at the fractured rock scale and at the grain scale; b over short timescales, highly localized thermal stresses cause mechanical deformation/failure of the propping asperities; c over relatively short timescales, pressure dissolution of asperities may occur; d over longer timescales, and triggered by higher temperatures, mineral dissolution of the free faces along the fracture wall and possibly mineral precipitation at open fracture spaces may occur