"Gneiss 1" by James St. John is licensed under CC BY 2.0
Definition of Metamorphic Rock
There are many types of rock. One type of rock is metamorphic rock. This metamorphic name is a name for the type of rock that complements igneous and sedimentary rocks. This metamorphic rock is often referred to as metamorphic rock. Metamorphic rock or metamorphic rock is a group of rocks that are the result of the alteration or transformation of a pre-existing rock type (protolith) by a process called metamorphosis or changing shape.
This metamorphic rock has very important uses for humans. Through research conducted on these metamorphic rocks can be obtained very important information about the temperature and pressure that occurs deep in the earth's surface. However, nowadays many metamorphic rocks have been exposed on the earth's surface due to soil erosion and uplift.
The Process of Occurrence of Metamorphic Rocks
This metamorphic rock is not a type of rock that directly exists in this world. To turn into metamorphic rock, it takes several processes. The process of the occurrence of these metamorphic rocks comes from pre-existing rocks, namely protoliths. Protolith or original rock that is subjected to heat of more than 150 degrees Celsius and also extreme pressure will experience major physical or chemical changes. There are many types of protolith rocks. Included in this protolith rock are igneous rock, sedimentary rock, or it could be other metamorphic rocks of older age such as Gneiss, slate, marble, and schist stones.
Types of Metamorphic Rocks
There are various types of Metamorphic Rocks and not just one. This metamorphic rock can be divided into three types, namely contact metamorphic rock, dynamo metamorphic odor, and pneumatolist contact metamorphic rock. To get to know each of these metamorphic rocks closer, we will discuss them one by one.
Contact metamorphic rock
The first type of metamorphic rock we will discuss is the contact metamorphic rock type. Contact metamorphic rock is a type of metamorphic rock that undergoes metamorphosis as a result of very high temperatures or as a result of magma activity. There are also those who state that these contact metamorphic rocks are rocks formed due to the influence of magma intrusion at very high temperatures. The existence of very high temperatures originating from this magma activity causes changes in the shape and color of the rock. This high temperature is also due to its proximity to magma. Examples of these contact metamorphic rocks are limestone or limestone into marble, then batholiths, lacolitic rocks, and sill rocks. One thing we need to know about this type of rock,that is, this type of rock is influenced by the location of the intrusion, where the farther it is from the intrusion, the degree of metamorphosis will decrease.
Dynamo metamorphic rock
The second type of metamorphic rock is dynamo metamorphic rock. Dynamo metamorphic rock is a type of rock that undergoes metamorphosis as a result of high pressure originating from endogenous forces for a long time, and is produced in the process of forming the earth's crust due to endogenous forces. This dynamo metamorphic rock usually occurs or is in the upper part of the earth's crust. The existence of pressure in the opposite direction causes changes in mineral grains, some are flat and some are back into crystal form. Some of these types of metamorphic rocks turn into crystals. Examples are pulverized rock and shale. Another example of dynamo metamorphic rock is mud stone or mud stone into slate or slate. This type of rock is often found in areas of faults or folds.
Pneumatolytic contact metamorphic rocks
The next type of metamorphic rock is pneumatolist contact metamorphic rock. This type of rock is a rock that undergoes a metamorphic process as a result of the influence of the gases present in the magma. The influence of this hot gas causes changes in the chemical composition of the minerals of this rock. An example of a pneumatolist contact metamorphic rock is quartz with borium gas turning into tourmaline or a kind of gemstone. Another example of this type of stone is quartz stone with fluorium gas and housed into topaz.
Those are the kinds or types of metamorphic rocks that are around us or that we often encounter. Metamorphic rock is basically a type of rock that has undergone a metamorphic process. Metamorphosis that occurs in rock itself is a process in which an object changes form from one form to another. In this stone metamorphosis, the metamorphosis process consists of various kinds and not just one.
Types of Metamorphic Rock Metamorphic
Metamorphic rock is a type of rock that undergoes a metamorphic or metamorphic process. The process of rock metamorphism itself consists of three kinds, namely thermal metamorphosis, dynamo metamorphosis, and also regional metamorphosis. Then, what exactly is the meaning of each type of metamorphosis?
Thermal Metamorphosis
Thermal metamorphosis is also known as touch metamorphosis, where this type of metamorphosis is a metamorphosis that occurs when rocks are touched by hot magma around the magma chamber or intrusive rock bodies. An example of this thermal or touch metamorphosis is limestone turning into marble.
Dynamo's Metamorphosis
The next type of metamorphosis is dynamo metamorphosis or also known as pressure metamorphosis. This type of metamorphosis is a metamorphosis that occurs where there is rock that is exposed to pressure from tectonic events (on the earth's crust only occurs at the top) so that it will undergo metamorphosis. An example of this type of metamorphosis is in the fault plane a friction mirror or milonite flour is formed.
Regional Metamorphosis
The next type of metamorphosis is regional metamorphosis. Regional metamorphosis is also known as dynamic metamorphosis. Regional metamorphosis is a metamorphosis that affects a very wide area that occurs at the bottom of the earth's crust as a result of pressure throughout the formation of schist, mica, phyllite, and gneiss. Rocks can undergo metamorphosis only with or if they are at great depths below the earth's surface, experience high temperatures, and also experience great pressure caused by the enormous weight of the rock layers above and will disrupt the structure of the earth.. This regional metamorphosis tends to make the rock harder, and at the same time causes the formation of a foliated, schistos, or gneiss texture consisting of a mineral palanar arrangement. This causes plate or prismatic minerals such as mica and hornblende to have the longest axes that are parallel to each other. The main characteristic of metamorphic rocks that undergo this type of metamorphosis is the presence of a shiny color and also not fossilized.
Cataclastic Metamorphosis
Next there is a type of cataclastic metamorphosis. This cataclastic metamorphosis occurs as a result of mechanical deformation, such as when two bodies of rock slide past each other along a fault zone. Friction that occurs along the shear zone will generate heat, and the rock is mechanically deformed. The rock is then crushed and crushed as a result of the shift. This type of metamorphosis is not common confined to a narrow zone where a horizontal fault would occur.
Hydrothermal Metamorphosis
Next there is hydrothermal metamorphosis. Hydrothermal metamorphosis occurs when there are rocks that are changed at high temperatures and medium pressures due to hydrothermal fluids. This means that the rock is undergoing hydrithermal metamorphosis. This is common in basaltic rocks which generally lack hydrate minerals. This hydrothermal metamorphosis causes alteration to hydrate minerals rich in Mg – Fe such as talc, chlorite, serpentine, actinolite, tremolite, zeolite, and clay minerals rich in ore deposits are also often formed as a result of hydrothermal metamorphism.
Overlapping Metamorphosis
Then there is another type of metamorphosis, namely overlapping metamorphosis. Overlap metamorphosis will occur when sedimentary rocks are buried to a depth of several hundred meters, and temperatures greater than 300 degrees Celsius can develop in the absence of differential stress. New minerals grow, but the rock does not appear to be metamorphosed, the main mineral usually produced from this process is zeolite. This overlapping metamorphosis is an overlapping metamorphosis with diagnosis to some extent. and this metamorphosis can turn into regional metamorphosis with increasing temperature and pressure.
Those are some types of metamorphic processes that can occur in metamorphic rocks. The process of metamorphosis that occurs in this stone occurs because it is natural and occurs because of natural processes. The metamorphosis process that occurs in these rocks occurs due to natural processes involving certain elements such as water, wind, air temperature, sunlight, and so on. All that are involved in the metamorphosis process of this rock are natural materials or those that can be found in nature and cannot be made by humans.
The process of metamorphosis itself takes time. To be able to turn into a good stone and a perfect stone, the metamorphosis process itself requires supportive conditions, including the surrounding environment and time. The time required is also quite long and even quite long. Without human knowledge, these stones already exist and we ourselves are not aware of it. This is what is called a natural process.
Impact of Metamorphosis
The metamorphosis process experienced by these rocks not only produces certain stones, but also we will get certain impacts from this metamorphosis process.
When extraterrestrial material, such as types of solar system types such as meteorites or comets, falls to earth, or in the event of a very large volcanic explosion, very high stresses can occur in the affected rocks.
These very high pressures produce minerals that can only be stable at very high pressures, such as SiO2 polymorphs such as coesite and stishophyte.
In addition they can also produce textures known as shock lamellae in mineral grains and also textures like or resembling broken cones in impacted rock.
That is the impact of the metamorphosis process. That's a little information about metamorphic rocks. Although not very complete but hopefully can provide useful knowledge.
