Tag: the earth's structure

The earth is made up of three layers, one inside the other like an onion. They are the crust, the mental and the core. The topmost layer, that is, the crust is solid, the thinnest and the lighter. The average density is 2.75 to 2.90. The thickness is 8 to 100 km. Below this top layer is the layer of basalt rock which is heavier than the topmost layer, i.e, the mental. The average thickness is 100 2900 km and the density varies from 3.1 to 5.00. The innermost layer is the core. The core contains 1/3 of the entire mass of the world. The average density is 5.1 to 13.00.

Earth mainly consists of four layers namely crust, mantle, outer core and inner core.

Widest of all the layers of earth is Mantle which is 1800 thick. It is composed mostly of silicate rocks rich in magnesium and iron.

Basalt is dark coloured igneous rock mainly composed of pyroxene mineral. It most commonly forms as an extrusive rock, such as a lava.The oceanic crust consists of a volcanic lava rock called basalt. Oceanic crust is the thin crust underlying the oceans.

Basalt density present is equal to 3.0 g /cm'3

The crust of the earth is made up of different strata of rocks. As a result of movement inside the earth, these rock strata at times are forced up and down and thus fold mountain are created. So fold mountain are the result of large-scale earth movement caused by stresses in the earth's crust.

The oceanic crust consists of a volcanic lava rock called basalt. Oceanic crust is the thin crust underlying the oceans. Basalt is dark coloured igneous rock mainly composed of pyroxene mineral. It most commonly forms as an extrusive rock, such as a lava.

Basalt density present is equal to 3.0 g cm'3

Earth mainly consists of four layers namely crust, mantle, outer core and inner core.

Lithosphere is the rigid outer layer of the earth which includes crust and uppermost mantle.

Crust: This is about 8 km thick inside and is highly explored. The continental crust is composed mostly of granite. The oceanic crust consists of a volcanic lava rock called basalt.

Mantle: It is composed mostly of silicate rocks rich in magnesium and iron.

The topmost layer of the earth is solid, the thinnest and the lightest and is known as lithosphere. The lithosphere has two layer- the outer part and the inner part. The outer part which is immediately below the newer sedimentary formation, i.e, crust. The outer layer of lithosphere mainly found under the continent and inner layer it mostly found partly under oceans. The inner layer again has three layers, i.e, SIAL which is made of silica and aluminum. The average thickness is 8 to 100 km. The layer next to it is SIMA makeup of silica and magnesium and an average thickness of this layer is 100 to 2900 km. The innermost layer is NIFE madeup of nickel and ferrous and the density is 5.1 to 13.

• The hard resistant materials forming the earth's crust are called the rocks. Hence option A is correct
• In different types of rocks, different metals and minerals are found.
• Lava is the molten material that gets ejected out of a volcano.

• The earth's crust is the outermost layer of the earth which has cooled down while the inner layers are still burning. When things cool after burning they get wrinkled up hence the earth's crust is largely wrinkled.
• It is plain, plateau and mountainous at different places and rocky as well. The most appropriate answer is option C ie wrinkled.

• The core of the earth is made up of heavy minerals like iron and nickel hence statement in option A is incorrect which makes it the right answer.
• Rest statements are true 
• The outer core is made up of molten rocks, its estimated temperature is 3300 degrees C and the inner core acts like a solid mass.
• Note- inner core is solid and the outer core is liquid.