Rocks and Soils

Rocks and Soils

Week 2- Science 

What is a rock ? 

A rock is a solid material found in nature. Rocks are made up of one or more minerals. 

What are minerals ? 

A mineral is a natural material that was never alive. 

Where can we find rocks ?

• Rocks are found all over the Earth. 

• Not all rocks are the same. They don't all look the same and they are not all made of the material.

• Different kinds of rocks are found in different places on Earth. 

Rocks and Minerals

Certain minerals make up each kind of rock. For example, feldspar and quartz make up most of the rock called granite. 

You can see that different kinds of rock have different colors. The colors come from the minerals in the rock. Granite can be pink, yellow, or other colors. The colors come from a mineral called feldspar.

What is soil ? 

The top part of Earth’s land is mostly covered with a material called soil. Soil is made up of rocks, minerals, and the remains of living things. 

What is soil made of ?

• Very tiny pieces of rock, called particles, are the main material in soil.

• Soil also contains the remains of dead plants and animals. Over time, the dead plants and animals break down into small bits.

• Soil also contains minerals and water. The amount of water soil can hold depends on the kind of soil.
  
  

Soil : Sand 

• Sand has the largest particles.

• Sand contains the mineral quartz.

• Sand has different colors because it comes from different- colored rocks.

• Sand has large air spaces between the particles. Water flows easily through the spaces, so sand does not hold water well.

Soil : Silt

• The particles of silt are smaller than those in sand.

• Silt feels more smooth when you touch it. 

• Silt holds water better than sand does. 

• Rivers carry silt from one place to another. When a river floods the land, the water leaves silt behind.

Soil : Clay

• Clay is the kind of soil with the smallest particles.

•  If you squeeze some clay in your hand, it feels sticky and smooth. 

• Clay can be different colors, but most clay looks reddish or brown.

• Clay holds water very well.

Soil : Loam

• Many soils are a mixture of sand, silt, and clay. These soils are called loam. 

•  Loam feels crumbly.

• Most kinds of plants grow best in loam. It holds water well.