GeoMiner Free earth-science tools

Built by a geologist

Magma identification and geology

Molten or partially molten rock beneath the Earth's surface, containing dissolved gases and suspended crystals. Magma is generated by partial melting of the mantle or crust and rises buoyantly toward the surface, where it may intrude as plutonic bodies or erupt as lava. Magma composition, temperature, volatile content, and viscosity control eruptive style and the types of igneous rocks produced. Field: petrology. Example: Basaltic magma beneath mid-ocean ridges has a temperature of approximately 1200°C and a low viscosity, allowing it to erupt effusively and flow as sheet flows and pillow lavas on the sea floor.. Related terms: Lava, Partial melting, Crystallization, Viscosity.

  • Browse all geology and mining glossary terms — Compare this entry with the complete GeoMiner glossary collection.
  • Previous: Mafic — Describing igneous rocks and magmas rich in magnesium and iron, with silica content typically between 45–52%.
  • Next: Mantle — The thick layer of silicate rock between the Earth's crust and outer core, extending from the Moho 5–70 km depth to the core-mantle boundary 2,900 km…
  • Lava
  • Viscosity

Sources, scope & corrections

These authoritative resources support category-level nomenclature, terminology, identification methods, and safety. When a specimen-specific safety warning appears, the public-health source listed here directly supports that precaution. They are not line-by-line citations for every other property on this entry, and natural specimens vary.

Editorial owner
GeoMiner
Last updated
2026-03-30T15:19:42.055955+00:00
Review status
Published; not independently peer-reviewed
  • USGS Thesaurus — U.S. Geological Survey. Controlled earth-science terminology used to describe USGS information resources.
  • Glossary of Geologic Terms — U.S. National Park Service. Geologic definitions prepared by the NPS Geologic Resources Inventory.

Read GeoMiner's editorial methodology or report a content issue.

Common questions

What does Magma mean in geology?
Molten or partially molten rock beneath the Earth's surface, containing dissolved gases and suspended crystals. Magma is generated by partial melting of the mantle or crust and rises buoyantly toward the surface, where it may intrude as plutonic bodies or erupt as lava. Magma composition, temperature, volatile content, and viscosity control eruptive style and the types of igneous rocks produced.
What is an example of Magma?
Basaltic magma beneath mid-ocean ridges has a temperature of approximately 1200°C and a low viscosity, allowing it to erupt effusively and flow as sheet flows and pillow lavas on the sea floor.
Which earth-science field uses the term Magma?
Magma is used in petrology.
Which terms are related to Magma?
Related terms in this reference are Lava, Partial melting, Crystallization, Viscosity.

JavaScript is loading the interactive GeoMiner experience. The identification tools provide educational candidates, not laboratory confirmation.