Answer: Increase in the extent of the sea.
Explanation: It is an invasion of the sea to the coasts caused by geological phenomena and that generally brings with it marine sedimentations. This action causes the continental lands to sink and may even be below sea level. This geological event can be long lasting and the sediments left on the coast by this elevation of the sea can be identified by the sedimentary column, who describes the location of these rocky sediments.
