Geosphere
The geosphere is the most solid, rocky part of Earth. It extends from the center of Earth to the surface of the Earth. The geosphere is divided into three layers based on chemical composition: the crust, the mantle, and the core.
The crust is the thin, outermost layer of the geosphere. The crust is divided into plates that move slowly over Earth's surface. The cruist beneath the oceans is called oceanic crust, and is only 5 to 10 km thick. The continents are made of continental crust, and ranges in thickness from about 15 to 70 km. Continental crust is thickest beneath the mountain ranges. The crust is made mostly of silicate minerals.
The mantle lies just below the crust. A small layer of the solid mantle, right below the crust, is just soft enough to flow. Movements in this layer move the plates of the crust. The mantle is about 2,900 km thick. It is made of silicate minerals that are more dense than those in the crust.
The central part of the Earth is the core, which has a radius of 3,400 km. It is made of iron and nickle and is very dense.
The crust is the thin, outermost layer of the geosphere. The crust is divided into plates that move slowly over Earth's surface. The cruist beneath the oceans is called oceanic crust, and is only 5 to 10 km thick. The continents are made of continental crust, and ranges in thickness from about 15 to 70 km. Continental crust is thickest beneath the mountain ranges. The crust is made mostly of silicate minerals.
The mantle lies just below the crust. A small layer of the solid mantle, right below the crust, is just soft enough to flow. Movements in this layer move the plates of the crust. The mantle is about 2,900 km thick. It is made of silicate minerals that are more dense than those in the crust.
The central part of the Earth is the core, which has a radius of 3,400 km. It is made of iron and nickle and is very dense.