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 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 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.
Which of the following is the main factor or regional metamorphism?
Answer: The main factors that control metamorphic processes are: The mineral composition of the parent rock. The temperature at which metamorphism takes place.
What happens during regional metamorphism?
Regional Metamorphism The differential stress usually results from tectonic forces that produce compressional stresses in the rocks, such as when two continental masses collide. Thus, regionally metamorphosed rocks occur in the cores of fold/thrust mountain belts or in eroded mountain ranges.
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 are three causes of regional metamorphism?
Controls, processes and causes 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 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.
What is another name for regional metamorphism?
Emerald mineralisation during regional metamorphism: the Habachtal (Austria) and Leydsdorp (Transvaal, South Africa) deposits. 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.
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.
Which site can regional metamorphism occur?
As described above, 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.
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:
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 two main components associated with regional metamorphism?
Metamorphism in Subduction Zones Temperature (T) and pressure (P) are two principal variables for metamorphism, leading to different metamorphic facies in response to changes in metamorphic thermal gradient at convergent plate boundaries (Brown, 2014; Zheng and Chen, 2017; Brown and Johnson, 2018).
What is the difference between regional and 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.
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.
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.
What causes dynamic metamorphism?
Dynamic metamorphism is the result of very high shear stress, such as occurs along fault zones. Dynamic metamorphism occurs at relatively low temperatures compared to other types of metamorphism, and consists predominantly of the physical changes that happen to a rock experiencing shear stress.
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 type of metamorphism is Metaconglomerate?
Metaconglomerate is a rock type which originated from conglomerate after undergoing metamorphism. Foliated metaconglomerate is created under the same metamorphic conditions that produce slate or phyllite, but with the parent rock (protolith) being conglomerate, rather than clay.
What are the grades of metamorphism?
Metamorphic grade refers to the range of metamorphic change a rock undergoes, progressing from low (little metamorphic change) grade to high (significant metamorphic change) grade. Low-grade metamorphism begins at temperatures and pressures just above sedimentary rock conditions.
What are the major differences 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. You just studied 7 terms!
What does the presence of Hornfels reveal?
What does the presence of Hornfels reveal? In biotite hornfels, a faint striping may indicate the original bedding of the unaltered rock and corresponds to small changes in the nature of the sediment deposited. More commonly there is a distinct spotting, visible on the surfaces of the hand specimens.
What are the three major agents of metamorphism?
The most important agents of metamorphism include temperature, pressure, and fluids.
What are the three factors that determine whether rock melts?
The three factors that affect whether rock melts include temperature, pressure, and the presence of fluids in the rock. Rock melts when the temperature of the rock increases to above the melting point of minerals in the rock. Rock melts when excess pressure is removed from rock that is close to melting.
What are 3 factors affect the formation of magma?
the formation of magma are temperature, pressure, water content, and mineral content. gradient. increases the rock’s melting point.