Question

Write a note on volcanic materials.

Answer 1

There are three main types of material that come out in volcanic eruptions namely liquid, solid, and gaseous form.

Liquid material:

1. It is the molten rock material. When the molten rock material is below the earth’s surface, it is called ‘Magma’.
2. When it appears on the surface it is called ‘lava’. On the basic of percentage of silica, it is classified as:
3. Acidic lava: It contains higher percentage of silica, (b) It has high melting point, (c) It is thick, fluid and moves slowly.
4. Basic lava: (a) It contains less percentage of silica, (b) It has low melting point, (c) It’s thicker, fluid and can flow over longer distance.

Solid material:

1. It consists of dust particles and rock fragments.
2. When the material is very fine, it is called volcanic dust.
3. The small sized solid particles are called ash.
4. The solid angular fragments are known breccias.
5. Sometimes, the lava material thrown into the air solidifies into small fragments before falling on the earth’s surface; it is called volcanic bombs.

Gaseous material:

1. At the time of volcanic eruption, a dark cloud of smoke can be seen over the crater.
2.  On the basis of shape, cloud is called cauliflower cloud.
3. Various inflammable gases are found in these clouds.
4. These gases produce flames.