Which one of the following terms are related to volcanoes?
1. Caldera
2. Erg
3. Pumice
4. Dykes
Choose the correct option from the codes given below:

Answer: [C] 1, 3 & 4

Calderas are large volcanic craters that form by two different methods: 1) an explosive volcanic eruption; or, 2) collapse of surface rock into an empty magma chamber. Pumice is a is a volcanic rock that consists of highly vesicular rough textured volcanic glass, which may or may not contain crystals. It is  typically light coloured.

This question is a part of GKToday's Integrated IAS General Studies Module