Magma Types and Processes

The video tutorial discusses magma chamber dynamics, focusing on the process of assimilation, where country rock is incorporated into magma, altering its composition. It explains the evidence for assimilation, such as xenoliths and inclusions, and uses variation diagrams to illustrate compositional changes. The tutorial also explores the relationship between magma processes and tectonic settings, highlighting how different environments affect magma evolution.

What is the primary process by which country rock is incorporated into a magma chamber?

• Erosion

• Melting

• Crystallization

• Sedimentation

What is the chemical formula of calcite, the primary mineral in limestone?

• Fe2O3

• MgCO3

• SiO2

• CaCO3

What term describes the contact zone around a magma chamber?

• Xenolith

• Enclave

• Inclusion

• Oriole

What is a xenolith?

• A type of mineral

• A type of rock formation

• A foreign lithic fragment in magma

• A fragment of magma

What is the primary evidence for assimilation in the form of textural evidence?

• Contact margins

• Xenoliths

• Mineral composition

• Temperature gradients

Which volcano's eruption provided a powerful example of magma assimilation using isotopes?

• Krakatoa

• Parícutin

• Vesuvius

• Mount St. Helens

What does a Harker variation diagram show?

• Magma chamber sizes

• Types of volcanic eruptions

• Variation in one element or isotope against another

• Temperature changes over time

What are the two different suites of magmas identified on Earth?

• Granitic and andesitic

• Subalkaline and alkaline

• Ultramafic and felsic

• Basaltic and rhyolitic

What type of environment is associated with subalkaline magmas?

• Mid-ocean ridges and subduction zones

• Transform boundaries

• Continental rifts

• Hot spots

Why is there no iron enrichment in subduction zone magmas?

• High pressure

• Low temperature

• High oxygen stabilizes magnetite

• Lack of olivine