Here's why:
* Solubility: Limestone is primarily composed of calcium carbonate, which is soluble in acidic water. Rainwater, slightly acidic due to dissolved carbon dioxide, can dissolve limestone over time, creating caves, sinkholes, and other karst features.
* Porosity and Permeability: Limestone often has a network of cracks, fissures, and pores, allowing water to easily penetrate and flow through it. This enhances the dissolving process.
* Other Karst-Forming Rocks: While limestone is the most common, other rocks like dolomite, marble, and gypsum can also form karst landscapes due to their solubility in acidic conditions.
Therefore, the presence of limestone is a key indicator of a potential karst topography.
