Question

Consider the following statements regarding Igneous rocks: Which of the statements given are correct?

1. They are formed through the solidification of magma.
2. The word 'Ignis' refers to the cooling process of water
3. They are known as Primary Rocks.

• A. All
• B. 2, 3
• C. 1, 3
• D. None of these

Answer 1

Answer:

C. 1, 3

Igneous Rocks: Formation and Characteristics

• Igneous rocks originate from the solidification and cooling of molten rock material, known as magma (beneath the Earth's surface) or lava (on the Earth's surface).
• The term 'igneous' is derived from the Latin word 'ignis' meaning 'fire', signifying their fiery origin from molten material.
• These rocks are also referred to as Primary Rocks because they are the first rocks to form from the cooling of the Earth's molten material during the planet's formation. All other rock types (sedimentary and metamorphic) are formed from the transformation or breakdown of igneous rocks.
• The characteristics of igneous rocks, such as their texture (grain size) and mineral composition, depend on the rate of cooling and the chemical composition of the magma/lava.
• Intrusive igneous rocks (e.g., granite) form when magma cools slowly beneath the Earth's surface, resulting in larger crystals.
• Extrusive igneous rocks (e.g., basalt) form when lava cools rapidly on the Earth's surface, resulting in smaller crystals or a glassy texture.
• Notable examples of igneous rocks include granite, basalt, obsidian, pumice, and gabbro.