Caves and Shafts of Catalonia by Rock Type

How rock type shapes cave formation

The vast majority of caves form by dissolution: slightly acidic rain and infiltration water slowly corrodes soluble rock such as limestone, gypsum or salt over thousands of years until it opens up passages and chambers. In poorly soluble rock (granite, slate) caves are far rarer and usually trace back to fractures or mechanical erosion rather than chemical dissolution. The catalogue distinguishes 15 different rock types among its registered caves.

Rock types with the most catalogued caves

By volume of catalogued caves, the dominant rock types are Limestone, Conglomerate, Dolomite, Sandstone and Granite, a direct reflection of how much karst relief Catalonia has.