Definition

1. Noun:
   • Molten rock material within the Earth's crust: Magma is a hot, fluid or semi-fluid mixture of molten rock, dissolved gases, and mineral crystals found beneath the Earth's surface. It is the source material for all igneous rocks.

Usage

• Magma is a geological term. It is used to describe the subterranean molten material from which igneous rocks form. When magma reaches the Earth's surface, it is called lava.

Examples

• Noun:
  • The volcano's eruption was caused by rising magma.
  • Geologists study the composition of magma to understand volcanic activity.
  • Magma chambers are reservoirs of molten rock below volcanoes.

Advanced Usage

• "Magma chamber": A large underground pool of molten rock.
  • The pressure in the magma chamber built up until it caused an eruption.
• "Magma plume" or "mantle plume": A column of hot, rising magma from deep within the Earth's mantle.
  • The Hawaiian Islands are thought to have formed over a stationary magma plume.

Variants and Related Words

• Magmatic (adj): Relating to or characteristic of magma.
  • The island's formation was due to magmatic activity.
• Magmatism (n): The emplacement and solidification of magma within or on the Earth's crust.

Synonyms

• Molten rock
• Melt (in geological contexts)

Related Phrases

• Partial melt: Not all components of a rock melt at the same temperature, creating magma with a specific composition.
  • The magma originated as a partial melt of the mantle.

Noun

1. molten rock in the earth's crust