Methods and systems for causing reaction driven cracking in subsurface rock formations are disclosed. In some embodiments, the methods include the following: drilling one or more holes in a substantially porous subsurface rock formation, the one or more holes in fluid communication with pores in the subsurface rock formation; injecting in the pores via at least one of the holes one or more fluids, wherein the one or more fluids include a gas; and chemically reacting the one or more fluids within the pores thereby causing cracking in the substantially porous subsurface rock formation.