How do cover-subsidence sinkholes form beneath soil?

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cave Stalactites and stalagmites in the Queen's Chamber, Carlsbad Caverns National Park, southeastern New Mexico.

Cover-subsidence sinkholes form through the gradual dissolution of soluble bedrock, such as limestone, beneath a layer of soil.1

The process occurs as follows:

Crack Formation: Slightly acidic groundwater infiltrates the soil and reaches the underlying bedrock, creating and widening cracks through chemical weathering.1
Soil Migration: As these cracks in the bedrock widen, the overlying soil particles gradually fall into the developing underground spaces.1
Surface Depression: This downward movement of soil causes a depression to form slowly at the surface.1

Unlike cover-collapse sinkholes, which result from the sudden failure of a cave roof, cover-subsidence sinkholes are typically shallower. They often receive local drainage, and the accumulation of sediment or the presence of a clay layer at the base can sometimes lead to the formation of small ponds or lakes.1