What are the 2 types of metamorphism?

What are the 2 types of metamorphism?

There are two main types of metamorphism:

• Contact metamorphism—occurs when magma contacts a rock, changing it by extreme heat (Figure 4.14).
• Regional metamorphism—occurs when great masses of rock change over a wide area due to pressure exerted on rocks at plate boundaries.

What are the 2 main types of metamorphic rocks?

Metamorphic rocks are divided into two categories- Foliates and Non-foliates. Foliates are composed of large amounts of micas and chlorites. These minerals have very distinct cleavage. Foliated metamorphic rocks will split along cleavage lines that are parallel to the minerals that make up the rock.

What 2 factors commonly cause metamorphism?

Metamorphism occurs because some minerals are stable only under certain conditions of pressure and temperature. When pressure and temperature change, chemical reactions occur to cause the minerals in the rock to change to an assemblage that is stable at the new pressure and temperature conditions.

What are the 2 key agents of metamorphism?

The most important agents of metamorphism include temperature, pressure, and fluids.

What are the 7 types of metamorphism?

Types

• Regional.
• Contact (thermal)
• Hydrothermal.
• Shock.
• Dynamic.
• Metamorphic facies.
• Metamorphic grades.
• Recrystallization.

What are the two main sources of heat for metamorphism?

heat and pressure. HEAT: There are two sources of heat, one comes from the geothermal gradient – the increase in temperature that occurs with increase in depth in the earth.

What type of rock is marble?

Marble. When limestone, a sedimentary rock, gets buried deep in the earth for millions of years, the heat and pressure can change it into a metamorphic rock called marble. Marble is strong and can be polished to a beautiful luster. It is widely used for buildings and statues.

What are the three factors that influence metamorphism?

Three general factors influence the changes that take place in rock during metamorphosis….These factors will be considered individually in the next sections.

• Temperature. Changes in temperature alter the mineral composition of rocks.
• Pressure.
• Presence of water.

What is the most important factor driving metamorphism?

Heat as a Metamorphic Agent – The most important agent of metamorphism is heat because it provides the energy to drive the chemical changes that result in the recrystallization of minerals.

What is the highest metamorphic grade?

Gneiss
Gneiss, the highest grade metamorphic rock, contains bands of easily visible quartz, feldspar, and/or mica.

What are the two 2 most common types of metamorphism?

Contact metamorphism. At shallow depths within the crust (usually less than 6 km) the heat sources responsible for contact metamorphism are bodies of hot magma (e.g.

What are the grades of metamorphism?

The degree or intensity of metamorphism that has affected a rock, is called grade of metamorphism Tilley has described as four types of grades 1.Very low grade 2.Low grade 3.Medium grade 4.High grade Increasing the grade of metamorphism is also accompanied by increasing the grain size of the rock.

What is low grade metamorphism?

Low-grade metamorphism takes place at temperatures between about 200 to 320 oC, and relatively low pressure. Low grade metamorphic rocks are generally characterized by an abundance of hydrous minerals.

What are the grades of metamorphic rock?

As we shall see, this determines the chemical changes that metamorphic rocks undergo. Grades of metamorphism range from very low (below 300°C) to low (300°C – 500°C) to medium (500°C – 600°C) to high (600°C and upwards).