Geography

1.CRUST

continental crust - Silica and Alumina

It is called - Sial

Oceanic crust - Silica and Magnesium

It is called - Sima

2. Mantle

3. CORE

It is formed by Nickel and Iron

It is called Nife.

There are Inner core and outer core.

Rocks and Minerals

1. Igneous rocks

2. Sedimentary Rocks

3. Metamorphic rocks

Metamorphic rocks are formed under great heat and pressure.

The Igneous and Sedimentary rocks change into metamorphic rocks.

Rock cycle

OUR CHANGING EARTH

Our changing earth

Formation of waterfall

Erosion

4.How are flood plains formed?

Ans)

During rains rivers overflow their banks.
This leads to the flooding of the nearby areas.
After the flood , a layer of fine material and other material is deposited over the plain in the form of sediments.
This leads to the formation of the flood plain.

5) what are sand dunes?

Ans) when the wind blows, it lifts and transports sand from one place to another. When it stops blowing the sand falls and gets deposited in low hill, these are called Sand dunes.

6)How are beaches formed?

Ans)The sea waves deposit sediments along the seashores. This results in the formation of beaches.

7) what are ox bow lakes?

Ans)When the meander loop is cut-off from the main river, it forms a cut-off lake.

Its shape is like an ox-bow.

Hence, the cut-off lake is called ox-bow lakes.

Ox bow lake