Top-Rated Free Essay

Metamorphic Rocks

Good Essays
Metamorphic Rocks

Axia College of the University of Phoenix

Metamorphic rock is the transformation of an existing rock type in a process called metamorphism, which means change in form. Metamorphic rocks make up a large part of the Earth 's crust and are classified by texture and by chemical and mineral assemblage (Murck, Skinner, & Mackenzie, 2008). Metamorphic rocks started out as some other type of rock, but have been substantially changed from their original igneous, sedimentary, or earlier metamorphic form. These rocks were once igneous or sedimentary rocks. Metamorphic rocks form when rocks are subjected to high heat, high pressure, hot, mineral-rich fluids or, more commonly, some combination of these factors (Murck, Skinner, & Mackenzie, 2008). The process of metamorphism does not melt the rocks, but instead transforms them into denser, more compact rocks.

There are two categories of metamorphic rocks foliated and non-foliated. In foliated metamorphic rocks, the composition of the original rock is not apparent. Metamorphic rocks have been modified by heat, pressure and chemical process usually while buried deep below the Earth 's surface (Murck, Skinner, & Mackenzie, 2008). Exposure to these extreme conditions has altered the mineralogy, texture and chemical composition of the rocks. Rocks exhibiting foliation include the typical sequence formed by the prograde metamorphism of mud rocks; slate, phyllite, schist and gneiss. Foliated rock is also known as S-tectonite in sheared rock masses.

The crystals in non-foliated rocks combine, change or rearrange, but they don 't form parallel bands, because they are composed of mostly one mineral. Non-foliated metamorphic rocks are formed around igneous intrusions where the temperatures are high but the pressures are relatively low and equal in all directions (Murck, Skinner, & Mackenzie, 2008). The original minerals within the rock recrystallize into larger sizes and the atoms become more tightly packed together, increasing the density of the rock. Non-foliated metamorphic rocks are identified on the basis of their composition. Non-foliated metamorphic rocks are most often derived from single mineral sedimentary rocks like limestone and quartz sandstone.

References

Murck, B. W., Skinner, B. J., & Mackenzie, D. (2008). Visualizing geology. Hoboken, NJ: John Wiley & Sons.

References: Murck, B. W., Skinner, B. J., & Mackenzie, D. (2008). Visualizing geology. Hoboken, NJ: John Wiley & Sons.

You May Also Find These Documents Helpful

  • Good Essays

    Metamorphic Rocks

    • 297 Words
    • 2 Pages

    Metamorphic rocks are originated within the earths crust. Metamorphic rocks are created when both pressure and heat meet at the right time. During metamorphosis the rocks do not melt the heat and pressure just change the make-up of the rock. There are two types of metamorphosis low grade and high grade. Low grade metamorphosis occurs at 400 degrees C and 400MPa, while high grade is anything above 400 degrees c and 400MPa. Once the temperature reaches a little over 600 degrees Celsius and over 600MPa…

    • 297 Words
    • 2 Pages
    Good Essays
  • Satisfactory Essays

    Metamorphic Rocks

    • 315 Words
    • 2 Pages

    A metamorphic Rock can be formed by simply being under the earth’s surface, being exposed to extremely high temperatures and a huge amount of pressure from the layers of rock above. These rocks can be formed by tectonic processes, some which include, continental collisions (this is a process that causes friction, distortion and horizontal pressure). These rocks can also be formed when rock becomes heated rapidly by the intrusion of a hot molten rock, (called magma) and it comes from the earth's interior…

    • 315 Words
    • 2 Pages
    Satisfactory Essays
  • Better Essays

    Metamorphic Rock

    • 1054 Words
    • 5 Pages

    Metamorphic Rock Metamorphism means to change form; this is exactly what metamorphic rocks do. This paper will take a look at the Earth’s rock cycle to examine exactly where the metamorphic rock fits into it. It will also look at how metamorphic rocks are formed and the relationship between metamorphic rocks and igneous rock and sedimentary rocks. This paper will examine the geological characteristics and materials of metamorphic rocks, and examine some examples of metamorphic rocks and will describe…

    • 1054 Words
    • 5 Pages
    Better Essays
  • Good Essays

    Metamorphic Rock

    • 459 Words
    • 2 Pages

    Metamorphic rocks are the transformation of the existing rocks, the protolith through the process of metamorphism. The Protoliths can be the igneous rock, sedimentary rock or any old metamorphic rock. Due to severe heat and pressure, the protolithis get various chemical or physical changes. These rocks create a huge part of the Earth's crust and these can be classified by the mineral and chemical assemblage and by the textures. Examples of the metamorphic rocks are: slate, gneiss, schist, marble…

    • 459 Words
    • 2 Pages
    Good Essays
  • Satisfactory Essays

    STATEMENT: geologists classify rocks based on how the rocks were formed. Rocks can be classified into three categories on the basis of their formation: igneous rocks, sedimentary rocks and metamorphic rocks. I. The first type is igneous rocks (from the Greek word for fire) which are formed from molten rock (magma) and lava. A. Formation 1.coming up of magma through cracks 2. forming a layer on surface or filling other cracks 3. cooling forming a very hard igneous rock 4. magma on the surface…

    • 292 Words
    • 2 Pages
    Satisfactory Essays
  • Good Essays

    Three Types of Rocks: There are three types of rocks and these three types of rocks are igneous, metamorphic, and sedimentary. These rocks all form differently. These rocks all can be made into another type of rock but they all are different and have probably been many different types of rocks. Igneous rocks form from cooling lava or magma. Igneous rocks that cool from lava have a much shorter cooling time than rocks that cool from magma, this is because magma is underneath the earths surface…

    • 355 Words
    • 2 Pages
    Good Essays
  • Good Essays

    be no rocks or plate boundaries. Every living thing on earth would have to adapt to these types of things, if there even was living things on earth. The different types of rocks like igneous, sedimentary, and metamorphic have to go through a process to become that type of rock. Igneous is formed when magma is cooled and hardens. Metamorphic rocks are the exact opposite, the rock is formed under the earth's surface, when heat and pressure are added. Lastly, sedimentary rocks are formed…

    • 604 Words
    • 3 Pages
    Good Essays
  • Better Essays

    Rocks

    • 977 Words
    • 4 Pages

    At a granular level, rocks are composed of grains of minerals, which, in turn, are homogeneous solids formed from a chemical compound that is arranged in an orderly manner. The aggregate minerals forming the rock are held together by chemical bonds. The types and abundance of minerals in a rock are determined by the manner in which the rock was formed. Many rocks contain silica (SiO2); a compound of silicon and oxygen that forms 74.3% of the Earth's crust. This material forms crystals with other…

    • 977 Words
    • 4 Pages
    Better Essays
  • Good Essays

    Rocks

    • 796 Words
    • 4 Pages

    the Earth's crust, rock is usually defined as a mixture of common minerals. Rocks can be hard or soft, as small as a grain or as large as a building. They have been an integral part of the history of mankind, first being used as tools for hunting and defense, and as a building materials to construct shelters and monuments. Combined with the effects of tectonics, weathering and vegetation, rocks define the natural landscapes we see around us. The minerals and metals we find in rocks are essential to…

    • 796 Words
    • 4 Pages
    Good Essays
  • Good Essays

    Rocks

    • 933 Words
    • 4 Pages

    WHAT ARE ROCKS? What are Rocks? Making up most of the Earth's crust, rocks are usually defined as a mixture of common minerals. Rocks can be hard or soft, as small as a grain or as large as a building. Combined with the effects of weathering and vegetation (vegetation can also weather rock as the tree or bush is "yanked" out of the ground by forces of wind or by merely falling over after it has died. Root systems tend to go under the surface and attach themselves to…

    • 933 Words
    • 4 Pages
    Good Essays