What is regional metamorphic rock?
[ rē′jə-nəl ] A type of metamorphism in which the mineralogy and texture of rocks are changed over a wide area by deep burial and heating associated with the large-scale forces of plate tectonics.
What causes regional metamorphism?
Regional metamorphism is caused by large geologic processes such as mountain-building. These rocks when exposed to the surface show the unbelievable pressure that cause the rocks to be bent and broken by the mountain building process. Regional metamorphism usually produces foliated rocks such as gneiss and schist.
What are the examples of regional metamorphism?
Regionally metamorphosed rocks usually have a squashed, or foliated appearance – examples include slate, schist and gneiss (pronounced “nice”), formed by metamorphism of mudstones, and also marble which is formed by metamorphism of limestone.
What happens regional metamorphism?
Regional metamorphic rocks form from other rocks (protoliths) by changes in mineralogy and texture in response to changing physical conditions (temperature, lithostatic pressure, and, in most cases, shear stress).
What is another word for regional metamorphism?
If the transformation is brought about mainly by heat, it is called contact metamorphism; if brought about by both heat and pressure, it is known as dynamothermal or regional metamorphism.
Can regional metamorphism happen?
Regional metamorphism includes any metamorphic process that occurs over a large region. It is therefore the most widespread and common type of metamorphism. There are three basic types of regional metamorphism, namely burial, ocean-ridge and the orogenic regional metamorphism.
Where is regional metamorphism found?
Regional metamorphism occurs when rocks are buried deep in the crust. This is commonly associated with convergent plate boundaries and the formation of mountain ranges. Because burial to 10 km to 20 km is required, the areas affected tend to be large. Most regional metamorphism takes place within continental crust.
What are the characteristics of regional metamorphism?
The rock produced is often a fine-grained rock that shows no foliation, called a hornfels. Regional metamorphism occurs over large areas and generally does not show any relationship to igneous bodies. Most regional metamorphism is accompanied by deformation under non-hydrostatic or differential stress conditions.
What are the two 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 grade of metamorphism is marble?
Marble
| Type | Metamorphic Rock |
|---|---|
| Color | Pink |
| Miscellaneous | Sugary; Biotite laminations; reacts with HCl |
| Metamorphic Type | Regional or Contact |
| Metamorphic Grade | Variable |
What is the difference between regional and contact metamorphism?
Contact metamorphism occurs when rocks are heated by magma or lava. this usually seen along the edges of igneous rocks. Regional metamorphism is when rocks buried deep beneath the earth’s surface are changed by high temperature and pressure. this usually occurs in large areas.
What is the example of dynamic metamorphism?
When directed pressure or stress is the dominant agent of metamorphism, it is termed dynamic; other terms are dislocation, kinematic, and mechanical metamorphism. Mineralogical changes occurring on a fault plane provide an obvious example.
What are the six types of metamorphism?
Top 6 Types of Metamorphism | Geology
- Type # 1. Contact or Thermal Metamorphism:
- Type # 2. Hydrothermal Metamorphism:
- Type # 3. Regional Metamorphism:
- Type # 4. Burial Metamorphism:
- Type # 5. Plutonic Metamorphism:
- Type # 6. Impact Metamorphism:
How does dynamic metamorphism happen?
Dynamic metamorphism is the result of very high shear stress, such as occurs along fault zones. At lower pressures and temperatures, dynamic metamorphism will have the effect of breaking and grinding rock, creating cataclastic rocks such as fault breccia (Figure 10.33).
Where does dynamic metamorphism occur?
Dynamic metamorphism takes place anywhere that faulting occurs at depth in the crust. Thus, mylonites can be found at all plate boundaries, in rifts, and in collision zones.
At what depth does metamorphism occur?
The metamorphic process usually occurs at pressures between 100 and 300 MPa, the depth at which these pressures occur depending on which type of rock is applying pressure.
What is the process of metamorphism?
Metamorphism is a process of mineral assemblage and texture variation that results from the physical-chemical changes of solid rocks, caused by factors such as crust movement, magma activity, or thermal fluid change in the earth.
What are the two most important sources of heat for metamorphism?
Heat that results in metamorphism is the result igneous intrusions and from deep burial. The two most important sources of heat for metamorphism are: A) intrusive magma bodies and deep burial.
What is the major source of heat for contact metamorphism?
Contact metamorphism occurs to solid rock next to an igneous intrusion and is caused by the heat from the nearby body of magma.
Which of the following is the best definition for contact metamorphism?
Contact metamorphism is a type of metamorphism where rock minerals and texture are changed, mainly by heat, due to contact with magma. Regional metamorphism is a type of metamorphism where rock minerals and texture are changed by heat and pressure over a wide area or region.