Granitic rock forms at depth, and comprises approximately two-thirds of the Earth's crust. In granites, water flows predominantly along fractures created by tectonic, thermal and erosional events.

Water is nature's most versatile tool ... forming an acidic concoction that dissolves rock. For example, acid rain dissolves limestone to form karst, a type of terrain filled with fissures ...

Over time, movement of groundwater in and around these bedrocks gradually dissolved them ... Sedimentary carbonate rock (limestone, dolomite) that has been eroded by water. Limestone: Sedimentary ...