STEP 1

1st Step: Another way a basin can form occurs when tectonic movements squeeze the seafloor horizontally, like pushing two edges of a piece of cloth toward each other.

STEP 4

STEP 2

STEP 3

2nd Step: When that happens, the seafloor starts to fold into ridges and dips, like an accordion. This puts the seafloor under great stress. As a result, cracks form in the sediment.

3rd Step: Seawater can go through the cracks, reach the salt deposits below, and begin to dissolve them. This is similar to the formation of caves in limestone deposits on land (known as karst topography).

4th Step: If enough salt dissolves, the evaporite becomes unable to support the heavy layers of sediment above it. The seafloor collapses, forming a deep basin. The process is very much like the formation of a sinkhole on land. If the seafloor collapses far enough, the resulting basin will reach the salt deposits, which can then dissolve directly into the water in the basin.