Limestone karst

Limestone karst formations shaped by millennia of erosion create dramatic and unique landscapes around the world.

About this subject

Limestone karst is a type of relief formed primarily by the chemical dissolution of carbonate rocks, such as limestone and dolomite, by acidic water. This process, called karstification, occurs when rain, slightly acidic due to atmospheric CO2, penetrates rock fissures, enlarging them over time. The result are landscapes marked by sinkholes, caves, dolines, towers, and conical peaks. The most iconic features are 'mogotes' or karst towers, which can reach hundreds of meters in height.

In Brazil, karst is expressive in regions such as the Peruaçu Caves National Park (MG) and the Bonito region (MS), where limestone gives rise to underground rivers, ornate grottos, and aquifers of extreme water importance. Globally, the largest examples are in southwestern China (Guilin and Yangshuo), Vietnam (Ha Long Bay), and the Balkans. The term 'karst' originates from the Karst region in Slovenia.

Beyond scenic beauty, karst has ecological and economic relevance. It houses aquifers that supply millions of people but are vulnerable to contamination. Limestone quarrying for cement and agriculture threatens these landscapes. UNESCO recognizes several karst sites as World Heritage, such as Phong Nha-Ke Bang National Park in Vietnam.

Frequently Asked Questions

How are limestone karst formations formed?

They form by the chemical dissolution of limestone rock by slightly acidic water, which enlarges fractures and creates caves, sinkholes, and towers over thousands of years.

Where can karst landscapes be found in Brazil?

In Peruaçu Caves National Park (MG), the Bonito region (MS), and parts of Chapada Diamantina (BA), among other carbonate rock areas.

What is the ecological importance of karst?

Karst aquifers supply fresh water to millions of people but are highly susceptible to pollution. Caves host unique fauna and paleontological records.