Was land once under a ocean?

- Fossils of marine organisms: Fossils of marine organisms, such as seashells, corals, and fish, are found in sedimentary rocks on land. This indicates that these areas were once covered by ocean.

- Salt deposits: Salt deposits, such as salt flats and salt domes, are found in many parts of the world. These deposits are formed when seawater evaporates, leaving behind the salt. This indicates that these areas were once covered by ocean.

- Wave-cut platforms: Wave-cut platforms are flat, horizontal surfaces that are found along coastlines. They are formed by the erosion of cliffs by waves. The presence of wave-cut platforms indicates that sea level was once higher than it is today.

- Seafloor spreading: The theory of seafloor spreading states that the ocean floor is constantly moving apart. As new ocean floor is created, old ocean floor is destroyed. This process can cause landmasses to collide, which can result in the formation of mountains. The Himalayas, for example, were formed when the Indian Plate collided with the Eurasian Plate.

- Continental drift: The theory of continental drift states that the continents are constantly moving. This process can cause landmasses to move into different climate zones, which can result in changes in the flora and fauna. For example, the Sahara Desert was once a lush rainforest.