Question

Which of the following natural processes is most likely to support the formation of an underwater sinkhole?

Answer 1

Answer:

Limestone cave collapsing due to changes in sea level.

Explanation:

Sinkholes are common where the rock below the land surface is limestone or other carbonate rock, salt beds, or in other soluble rocks, such as gypsum, that can be dissolved naturally by circulating ground water. Sinkholes also occur in sandstone and quartzite terrains.

Answer 2

Answer:

Option B. Limestone cave collapsing due to changes in sea level.

Explanation:

Sink holes, as their name suggests, are formed by the collapse of limestone caves due to changes in sea levels. This occurs due to special properties of limestone.

Limestone is calcium carbonate (CaCO₃). It easily breaks down when it comes in contact with an acidic environment. This causes the rocks to start flaking off. The limestone caves are formed into two features: stalagmites and stalactites. Stalagmites are pointed features that originate from the floor of the curve.

Stalactites are sharp pointed extrusions that hang down from the ceiling of the roof. Because of the continued melting, the limestone eventually gives in, collapsing and the ground above it collapsing as well. This results in a sinkhole.