The Composition and Structure of Earth

Page 1

Lithosphere: is composed of both the crust and the portion of the upper mantle that behaves as a brittle, rigid solid. 100km thick

Asthenosphere: is partially molten upper mantle material that behaves plastically and can flow.

Oceanic crust (basaltic): is composed of magma that erupts on the seafloor to create basalt lava flows or cools deeper down to create the intrusive igneous rock gabbro. Sediments, primarily muds and the shells of tiny sea creatures, coat the seafloor. Sediment is thickest near the shore where it comes off the continents in rivers and on wind currents. The oceanic crust is less dense than the continental crust. Oceanic crust: dense, basaltic rock

Continental crust (granitic): Is made up of many different types of igneous, metamorphic, and sedimentary rocks. The average composition is granite, which is much less dense than the mafic igneous rocks of the oceanic crust. 7-70 km thick. Continental crust is less dense oceanic crust. Granitic

The mantle: is hot and represents about 68 percent of Earth’s mass.he mantle is hot and represents about 68 percent of Earth’s mass. The upper mantle is 660km long. More than 82% of Earth's volume.

The core: Is mostly iron-nickell metal.

Outer core (liquid): Earth's magnetic field (the moving he reason).

Inner core (solid): distance from the crust to the inner core is from 6371 km.

To the Mayans, the world was flat, and its corners, four jaguars (known as bacabs) held up the sky.

The ancient Persians

- Solid Earth

- Based on compositional differences, it consists of the crust, mantle and core.