Metamorphic rocks were once sedimentary, igneous or even other metamorphic rocks that have been changed by heat and pressure. Contact metamorphism occurs when magma intrudes or forces its way into existing rock. The heat of the magma bakes the surrounding rocks causing them to change. This is a local event.
What are the causes of metamorphism?
Contact metamorphism occurs typically around intrusive igneous rocks as a result of the temperature increase caused by the intrusion of magma into cooler country rock. The area surrounding the intrusion where the contact metamorphism effects are present is called the metamorphic aureole.
What are the different types of metamorphism?
There are two major kinds of metamorphism: regional and contact. Regional metamorphism. Most metamorphic rocks are the result of regional metamorphism (also called dynamothermal metamorphism). These rocks were typically exposed to tectonic forces and associated high pressures and temperatures.
What are the three most important agents of metamorphism?
The three agents of metamorphism are heat, pressure, and chemically active fluids. Heat is the most important agent of metamorphism because it provides the energy that drives the chemical reactions responsible for mineral and textural changes during metamorphism.
Is slate a metamorphic rock?
Slate is a fine-grained, foliated, homogeneous metamorphic rock derived from an original shale-type sedimentary rock composed of clay or volcanic ash through low-grade regional metamorphism. It is the finest grained foliated metamorphic rock.
What are the three different types of metamorphism?
There are three ways that metamorphic rocks can form. The three types of metamorphism are Contact, Regional, and Dynamic metamorphism. Contact Metamorphism occurs when magma comes in contact with an already existing body of rock.
What is the grade of metamorphism?
Metamorphic Grade is a scale of metamorphic intensity which uses indicator minerals as geothermometers and geobarometers. SLATE -> PHYLITE -> SCHIST is a sequence of metamorphic rocks of increasing grade. The corresponding indicator minerals are chlorite, biotite and garnet.
What are the agents of metamorphism?
AGENTS OF METAMORPHISM – The agents of metamorphism include heat, pressure (stress), and chemically active fluids. During metamorphism, rocks are often subjected to all three metamorphic agents simultaneously.
How is a metamorphic rock formed?
They do not melt, but the minerals they contain are changed chemically, forming metamorphic rocks. Sometimes, metamorphic rocks are formed when rocks are close to some molten magma, and so get heated up. Remember that metamorphic rocks are not made from melting rock. (Rocks that do melt form igneous rocks instead.)
How is a metamorphic rock formed for kids?
Metamorphic rocks form deep within the Earth when heat and pressure are applied to either igneous rocks or sedimentary rocks. One very common metamorphic rock is marble. Marble is formed when heat and pressure are applied to limestone for many thousands of years.
What is in a metamorphic rock?
Metamorphic rocks are created by the physical or chemical alteration by heat and pressure of an existing igneous or sedimentary material into a denser form. Examples of metamorphic rocks are schist (converted basalt), quartzite (compressed sandstone), and marble (compressed limestone or dolomite).
What is an example of a metamorphic rock?
Examples of metamorphic rocks include anthracite, quartzite, marble, slate, granulite, gneiss and schist. Anthracite is a type of coal with a high carbon count, few impurities and with a high luster (meaning it looks shiny). Marble is a metamorphic rock that is formed from the sedimentary rock limestone.
Which is the highest grade metamorphic rock?
Schist, the next higher grade rock, typically contains easily visible crystals of muscovite or biotite. Gneiss, the highest grade metamorphic rock, contains bands of easily visible quartz, feldspar, and/or mica. More metamorphic rocks.
Where is regional metamorphism found?
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 the use of metamorphic rocks?
Uses of Metamorphic Rocks. Quartzite and marble are commonly used for building materials and artwork. Marble is beautiful for statues and decorative items such as vases (see an example in Figure below). Ground up marble is also a component of toothpaste, plastics, and paper.
How the rocks are formed?
Igneous rocks are formed when melted rock cools and solidifies. Melted rock may come in the form of magma, when it is found underneath the Earth’s surface. It can also come in the form of lava, when it is released unto the Earth’s surface during a volcanic eruption.
Do metamorphic rocks contain crystals?
Igneous; they form from the cooling of magma deep inside the earth. They often have large crystals (you can see then with the naked eye). Metamorphic; they are formed through the change (metamorphosis) of igneous and sedimentary rocks. They can form both underground and at the surface.
What are some of the characteristics of metamorphic rocks?
Characteristics of Metamorphic Rocks. Metamorphism involves the alteration of existing rocks by either excessive heat and pressure, or through the chemical action of fluids. This alteration can cause chemical changes or structural modification to the minerals making up the rock.
What is the parent rock?
Parent rock, also referred to as substratum, refers to the original rock from which something else was formed. It is mainly used in the context of soil formation where the parent rock (or parent material) normally has a large influence on the nature of the resulting soil.
What are the characteristics of metamorphic rocks?
Metamorphic Rocks. Metamorphic rocks were once igneous or sedimentary rocks, but have been changed (metamorphosed) as a result of intense heat and/or pressure within the Earth’s crust. They are crystalline and often have a “squashed” (foliated or banded) texture.
What is the definition of a metamorphic rock?
A metamorphic rock is a type of rock which has been changed by extreme heat and pressure. Its name is from ‘morph’ (meaning form), and ‘meta’ (meaning change). The original rock gets heated (temperatures greater than 150 to 200 °C) and pressured (1500 bars). This causes profound physical and/or chemical change.