Sinkholes can for when: A. <span>Rainwater containing carbon dioxide dissolves underground rock
</span>Water in an underground rock<span> or sediment layer is groundwater. </span>Underground<span> water </span>can<span> also erode and deposit material. </span>Rainwater<span> absorbs </span>carbon dioxide<span> (</span><span>CO2) as it falls. The CO2 groundwater creates landforms by </span>dissolving<span> away </span><span>rock.</span>
