Soil, Rocks and Minerals
The Tajmahal, considered one of the wonders of the modern world, is made entirely out of marble. It also has gemstones embedded as decorations. Gemstones are precious rocks.
- The land on the earth is made up of soil and
Rocks are made up of minerals.
- There are three kinds of rocks - igneous, sedimentary and metamorphic.
- Igneous rocks are also known as fiery Igneous rocks such as granite and basalt are formed when magma cools above the surface of the earth,
- Granite rock is made of mica, quartz and
- Sedimentary rocks are formed from older rocks that have been broken into tiny fragments.
- g., Shale, sandstone, conglomerate and limestone. Sand stone is made of quartz.
- Metamorphic rocks are formed when igneous or sedimentary rocks undergo changes due to heat and pressure.
e.g., Marble, slate, quartzite and gneiss.
- Rocks are used as building materials, for extracting metals and as gemstones in jewelry.
- Coal is a sedimentary rock formed from the remains of plants.
- Petroleum is formed from the remains of plants and animals in the sea.
- Soil is formed by the breaking down of rocks into smaller pieces.
The process of wind or flowing water washing away the top part of soil is known as soil erosion.
- Deforestation, farming and over-grazing increases soil erosion.
- The protection of soil from erosion is known as soil conservation.
- Soil can be conserved through terrace or step-farming, afforestation, by providing soil cover, growing shelter belts and by building embankments.