What is the difference between regional and contact metamorphism?
What is the difference between regional and contact metamorphism?
Metamorphism is the solid change in minerals and textures in a pre-existing rock (country rock) due to changing pressure / temperature conditions. Conversely, contact metamorphism usually occurs under higher temperature conditions associated with ignorant intrusions on a smaller scale. …
What is the difference between regional and contact metamorphism quizlet?
Regional Metamorphism- metamorphism affecting rocks over an extensive area as a result of large scale action of heat and pressure. Contact metamorphism rocks will have larger crystals and will be darker and more dense as a result because the heat and pressure is more concentrated. The state rock is a metamorphic rock.
How do you tell the difference between a contact metamorphic rock and a regionally metamorphosed rock just by looking at them?
Contact metamorphism produces non-foliated (rocks without any cleavage ) rocks such as marble, quartzite, and hornfels. Regional Metamorphism occurs over a much larger area. This metamorphism produces rocks such as gneiss and schist. Regional metamorphism is caused by large geologic processes such as mountain-building.
What is contact metamorphism?
Contact metamorphism is a static thermal metamorphism in the vicinity of hot intrusive igneous bodies, and metamorphic rock is formed within the zone of contact metamorphism—contact aureole (Figure 8-1).
What is an example of contact metamorphism?
Contact metamorphism occurs when magma intrudes or forces its way into existing rock. An example of contact metamorphism is the metamorphic rock marble. Marble is created from limestone that has been subjected to heat. Regional metamorphism by contrast takes place over large areas and is high-grade metamorphism.
Where is contact metamorphism found?
Contact metamorphism is usually restricted to relatively shallow depths (low pressure) in the Earth because it is only at shallow depths where there will be a large contrast in temperature between the intruding magma and the surrounding country rock.
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 are the main factors of contact metamorphism?
The main factors that control metamorphic processes are:
- The mineral composition of the parent rock.
- The temperature at which metamorphism takes place.
- The amount and type of pressure during metamorphism.
- The types of fluids (mostly water) that are present during metamorphism.
- The amount of time available for metamorphism.
What is an example 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 are the characteristics of regional metamorphism?
Regional metamorphism: Changes in enormous quantities of rock over a wide area caused by the extreme pressure from overlying rock or from compression caused by geologic processes. Deep burial exposes the rock to high temperatures.
What is the cause of 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 is the definition of regional metamorphism?
Regional metamorphism is metamorphism that occurs over broad areas of the crust. Most regionally metamorphosed rocks occur in areas that have undergone deformation during an orogenic event resulting in mountain belts that have since been eroded to expose the metamorphic rocks.
Is phyllite regional or contact?
| Summary Chart of Common Metamorphic Rocks | ||
|---|---|---|
| Original Rocks | Metamorphic Equivalent | Metamorphism |
| sandstone | quartzite | regional & contact |
| shale | slate >> phyllite >> schist >> gneiss | regional |
| limestone | marble | contact |
Which sites can regional metamorphism happen?
Most regional metamorphism takes place within continental crust. At this continent-continent convergent boundary, sedimentary rocks have been both thrust up to great heights (nearly 9,000 m above sea level) and also buried to great depths.
Which setting is most common for regional metamorphism?
Most regional metamorphism takes place within continental crust. While rocks can be metamorphosed at depth in most areas, the potential for metamorphism is greatest in the roots of mountain ranges where there is a strong likelihood for burial of relatively young sedimentary rock to great depths.
What is the main factor that affects regional metamorphism?
Answer: Temperature, hydrostatic pressure, and shearing stress, together with the chemical activity of percolating pore fluids, are the major physical variables governing the process of regional metamorphism.
What are the different types of metamorphism?
Three types of metamorphism exist: contact, dynamic, and regional. Metamorphism produced with increasing pressure and temperature conditions is known as prograde metamorphism.
What are the seven types of metamorphism?
Metamorphic grade is a general term for describing the relative temperature and pressure conditions under which metamorphic rocks form….Some terms that describe this general bulk chemical composition are as follows:
- Pelitic.
- Quartzo-Feldspathic.
- Calcareous.
- Basic.
- Magnesian.
- Ferriginous.
- Manganiferrous.
What is the process of metamorphism?
Process of Metamorphism: New minerals are created either by rearrangement of mineral components or by reactions with fluids that enter the rocks. Pressure or temperature can even change previously metamorphosed rocks into new types. Metamorphic rocks are often squished, smeared out, and folded.
What happens when metamorphism takes place?
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 is a dynamic metamorphism?
Dynamic metamorphism, or cataclasis, results mainly from mechanical deformation with little long-term temperature change. Textures produced by such adjustments range from breccias composed of angular, shattered rock fragments to very fine-grained, granulated or powdered rocks with obvious foliation and lineation.
What are the four types of metamorphism?
Top 4 Types of Metamorphism| Rocks | Geography
- Type # 1. Contact Metamorphism:
- Type # 2. Regional Metamorphism:
- Type # 3. Hydro-Metamorphism:
- Type # 4. Hydro-Thermo-Metamorphism:
At which location is dynamic metamorphism?
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.
Why is dynamic metamorphism different from the other types of metamorphism?
Dynamic metamorphism occurs due to brittle or ductile deformation of rocks that have experienced significant strain. Regional metamorphism is a type of metamorphism where rock minerals and texture are changed by heat and pressure over a wide area or region.
What is the difference between thermal dynamic and regional metamorphism?
Answer. Thermal metamorphism: Metamorphismcaused by high temperature is called thermal metamorphism. Dynamic metamorphism: Dynamic metamorphism refers to the alteration caused by high pressure during Earth’s movements.
Which type of metamorphism involves pressure?
Dynamic metamorphism involves high shear stress, high pressure, high strain, high fluid partial pressure and variable temperature.