15 Questions
What are the three high-level rock categories defined in geology?
Igneous rocks, sedimentary rocks, and metamorphic rocks
What determines the category of a rock?
How the rock type forms
What is a key point in the definition of metamorphic rocks?
The transformation happens in the solid state
What are the two most common types of metamorphism?
Regional and contact metamorphism
According to the principles of thermodynamics, what do all things try to reach?
A state of equilibrium corresponding to their surrounding conditions
What is the term used for the preexisting rock that experiences metamorphism?
Protolith
How do metamorphic rocks form?
When a preexisting rock experiences an environment different from the environment in which it formed
What are the examples of common protolith and resulting metamorphic rock?
Limestone and marble
What causes the change in crystal structure from limestone to marble?
Higher temperature and pressure
What distinguishes contact metamorphic rocks?
Primarily undeformed mineral crystals
What is the primary heat source for contact metamorphism?
Intrusion of magma
What distinguishes regional metamorphic rocks?
Prominent bands of aligned minerals
What causes the formation of regional metamorphic rocks?
Tectonic plate collisions
What is the difference in the scale of occurrence between contact and regional metamorphism?
Contact metamorphism occurs over a small area, while regional metamorphism occurs over a large area
What are examples of common regional metamorphic rocks?
Gneiss, slate, and schist
Study Notes
Rock Categories
- Geology defines three high-level rock categories: Igneous, Sedimentary, and Metamorphic rocks.
Metamorphic Rocks
- Metamorphic rocks are defined as rocks that have changed from their original form due to heat, pressure, and chemical reactions.
- A key point in the definition of metamorphic rocks is that they do not melt during the transformation process.
- The two most common types of metamorphism are contact metamorphism and regional metamorphism.
Thermodynamics
- According to the principles of thermodynamics, all things try to reach a state of lower energy or equilibrium.
Metamorphic Rock Formation
- Metamorphic rocks form when a preexisting rock, called the protolith, experiences metamorphism.
- The protolith can be any type of rock, and it undergoes changes in mineral composition, structure, or texture due to heat, pressure, and chemical reactions.
- Examples of common protolith and resulting metamorphic rock include:
- Limestone → Marble
- Shale → Slate
- Basalt → Eclogite
Contact Metamorphism
- Contact metamorphism occurs when magma intrudes into a rocks, causing a localized change in temperature and pressure.
- This type of metamorphism is characterized by a distinct change in crystal structure, such as the transformation from limestone to marble.
- Contact metamorphic rocks are distinguished by their distinctive mineral assemblages and textures.
- The primary heat source for contact metamorphism is the magma.
Regional Metamorphism
- Regional metamorphism occurs when rocks are subjected to increased pressure and temperature over a large area, such as during mountain-building events.
- This type of metamorphism is characterized by a gradual change in mineral composition and structure over a large area.
- Regional metamorphic rocks are distinguished by their widespread distribution and uniform mineral assemblages.
- The formation of regional metamorphic rocks is caused by the movement of tectonic plates.
- Regional metamorphism occurs on a much larger scale than contact metamorphism.
Examples of Regional Metamorphic Rocks
- Examples of common regional metamorphic rocks include quartzite, schist, and gneiss.
Test your knowledge of metamorphic rocks with this quiz! Learn about the formation and characteristics of metamorphic rocks and challenge your understanding of the geological processes that shape the Earth's surface.
Make Your Own Quizzes and Flashcards
Convert your notes into interactive study material.
Get started for free
