EVERYDAY SCIENCE

Detailed explanation-1: -The newest, thinnest crust on Earth is located near the center of mid-ocean ridge-the actual site of seafloor spreading. The age, density, and thickness of oceanic crust increases with distance from the mid-ocean ridge.

Detailed explanation-2: -Igneous rock is formed by the cooling and crystallization of molten magma at volcanoes and mid-ocean ridges, where new crust is generated. Examples of igneous rock are basalt, granite, and andesite (Fig. 7.57 A).

Detailed explanation-3: -Magma and Mid-Ocean Ridges: The Earth’s mid-ocean ridge system creates volcanoes and mountains along the seafloor. These ridges are also the place where new crust for the Earth is created.

Detailed explanation-4: -Seafloor spreading takes place at midocean ridges and produces basalt, the rock that makes up the oceanic crust. The Mid-Atlantic Ridge and East Pacific Rise are examples of midocean ridges.

Detailed explanation-5: -Mid-ocean ridges occur along divergent plate boundaries, where new ocean floor is created as the Earth’s tectonic plates spread apart. As the plates separate, molten rock rises to the seafloor, producing enormous volcanic eruptions of basalt.