Lithosphere (Upper Mantle and Crust)

Earth is divided into four spheres, the atmosphere, the hydrosphere, the biosphere, and the lithosphere. Spheres of the earth are explained in the previous post: Spheres of the Earth. As this chapter is about the interior of the Earth, therefore, we will discuss in this post only the Lithosphere of the Earth.

The Lithosphere:

Lithosphere of Earth

The upper solid layer of the Earth is known as Lithosphere. The upper mantle and the crust of the Earth are collectively called the Lithosphere. This region of lithosphere rests on a hot soft plastic-like layer: the Asthenosphere. Heat source inside mantle keep Asthenosphere in motion. Bright spots are zones in crust 15 to 20 km below the surface of Earth. It is layer, which reflect seismic waves more in lithosphere. The crust and the lithosphere as a whole is composed of many segments called the lithosphere plates are also known as tectonic plates. They move in response to the plastic flow in the hot Asthenosphere. In some mountains, the tectonic plates have come together in huge collisions.

Composition of Lithosphere:

So far as the composition of lithosphere is concerned, it is composed of many elements with different propositions. According to Clarke and Washington, it is made of igneous rocks (95%), shale (4%), sandstone(0.75%) and limestone(0.25%). These are composed of many elements which includes Oxygen(46.7%), Silicon(27.6%), Aluminimum(8.0%), Iron(5.0%), Calcium(3.6%), Sodium(2.7%), Potassium (2.0%), Magenisium(2.6%), Titanium(0.6%), and Hydrogen(0.14%). These elements are found in the form of compounds such as Anhydite (Calcium Sulphate/CaSo4), Aragonite (Calcium Carbonate/CaCO3), Calcite (Calcium Carbonate/CaCo3), Chalcedony (Silicon/SiO2), and Dolomite (Calcium Magnesium Carbonate (CaMg.CO3) 2 .

Lithospheric plates:

The Earth’s crust together with upper mantle (Lithosphere) is divided into segments separated along the ridges called lithosphere plates. They help us understand drifting movement of the continents. The scientists have concluded that if the ocean flours can move and spread then the continents can also do so. The plates can cause destruction if they move in appositive direction and collide. Collision results in earthquakes, volcanism and mountain building. There are many plates out which of the following are more important.

  • The specific plates (South Alaska to Antarctic plates)
  • The North American plate (North America)
  • The African plate (African and Madagascar)
  • The South American  plate (Westward from 20oN).
  • The Eurasian plate (Eurasia: North of Himalaya)
  • The Austalian India plate (Australia & India).
  • The Anstarctic plate ( Anstarctic Landmass).
  • The Nazca plate (Between South American and Pacific Plates)
  • The Caribbean Plate ( Cantral America & Caribean)
  • The Cocos Plate (Oceanic of Latin America)
  • The Scotic plate ( South of Latin America)
  • Jaun de Fuca plate ( US-Canada boundary: N.America)
  • Philippine Plate (Between Pacific & Eurasian plates)
  • Arabian Plate (Arabia)

Comments 2

  • […] Lithosphere is the upper most sold hard layer of the earth. Lithosphere consists of the earth’s crust and the upper mantle. The upper mantle and the earth’s crust, both are hard solid part of the earth. From here, the molten layers of the earth starts that are known as the molten mantle, and the liquid outer Core. Lithosphere is divided into the plate tectonics. The plates tectonic are the cracked shell of the earth crust and the upper mantle. These plate either submerge, or diverge or move transversely due to the convection in the lower mantle. Read detail of the Lithospheric layer of the earth. […]

  • Oһ my goodness! Awesome article dude! Thank you so
    much, However I am experiencіng problems with your RSS. I don’t understand the гeason why I cannot subscribe to it.
    Is there anybody having the same RSS problems? Anybody who knows the
    answer can you kindlʏ rеspond? Thanks!!

Leave a Reply

Your email address will not be published. Required fields are marked *