Question

Sinkholes can form when _____.

Answer 1

Sinkholes can for when:
A. Rainwater containing carbon dioxide dissolves underground rock

Water in an underground rock or sediment layer is groundwater. Underground water can also erode and deposit material. Rainwater absorbs carbon dioxide (CO2) as it falls. The CO2 groundwater creates landforms by dissolving away rock.

Answer 2

Heavy weight on soft soil can cause a collapse of ground. Sinkholes can form when the land surface is changed.