Give reasons for the following:

Lava activity is profitable to man.

Lava activity is profitable to man as:

1. Lava forms plains, which are very fertile. For example- plains in Java, Malwa region in Deccan plateau and parts of Brazil.
2. Lava activity also provides us precious stones, for example, diamonds in South Africa and nickel deposits of Sudbury in Canada.
3. Geysers and springs are formed due volcanic activity and are very useful from health point of view as they contain sulphur and other useful minerals.
4. The crater lakes are formed as result of volcanic eruption. They may serve as source of perennial rivers.
5. Volcanic spots become tourist spots.
6. Sometimes remnants of volcanoes after erosion help in preserving traces of old civilization.