The bottom of the ocean has feature has varied as those on land. Huge plains spread out across the ocean floor, and long mountain chains rise toward the surface. Volcanoes erupt from ocean bottom, and deep
valleys cut through the floor. In the early 1960s, a theory called SEA-FLOOR SPREADING provided some explanation. According to the theory, the sea floor itself moves, carrying the continents along. Circulating movements carry melted rock up to the mid ocean ridges and force it into the central valleys of the ridges. As the melted rock cools and hardens, it forms new sea floor and pushes the old floor and continents away from the ridges.
0 comments:
Post a Comment