I’m working on a geology question and need an explanation and answer to help me learn.
State the difference between magma and lava.
State and define the two main categories of igneous rocks.
- Processes that form magma – Explain three methods of melting by sketching and labeling a temperature-pressure diagram, stating the processes that occur, and where this type of melting occurs.
- Geologists classify magma based on its chemical composition: what are the four categories of magma and how much silica is there in each?
- List the four factors that play a role in the composition of magma. Write a brief phrase of what each factor is.
- State the two reasons why magma rises.
- Define viscosity and state three things it depends on.
- Fill in the blank: A _______ (mafc/felsic) magma is ________ (more/less) viscous, and therefore contains ________ (more/less) silica and votalies and ________ (will/will not) be more explosive.
- State the mechanisms that control the rate of magma cooling. State how the rate of magma cooling will affect the size of minerals.
- What is a magma chamber and where in the layers of the Earth does it form?
- Sketch and label the four types of intrusions (features) a magma can form — dike, sill, pluton, and batholith.
- State the two main characteristics geologists look at to classify and assign names to igneous rocks. What information does each of these characteristics provide?
- Sketch a chart (with composition in columns and texture in rows) you can use to identify an igneous rock (hint: see Figure 4.14b).