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Rocks are formed on Planet as igneous, sedimentary, or metamorphic rocks. Igneous rocks create as soon as rocks are heated to the melting suggest which creates magma. Sedimentary rocks are formed from the cementing together of sediments, or from the compaction (squeezing together) of sediments, or from the recrystallization of brand-new mineral grains which are larger than the original crystals. Metamorphic rocks form from warmth and push changing the original or parent rock right into a fully new rock. The parent rock deserve to be either sedimentary, igneous, or also one more metamorphic rock. Words "metamorphic" comes from Greek and also indicates "To Change Form".

You are watching: The figure above shows that sedimentary rocks are changed to sediment by ____.




The diagram over reflects you just how the rocks on Earth have actually been readjusted continually over time from one rock form to another. This altering of rock forms is referred to as the "Rock Cycle".


Solid rock deserve to be adjusted right into a brand-new rock by stresses that reason a rise in warmth and push. Tbelow are 3 primary agents that cause metamorphism. Factors that reason an increase in Temperature, Prescertain, and also Chemical transforms are the three agents that we are going to examine.

Temperature increases have the right to be caused by layers of sediments being buried deeper and deeper under the surchallenge of the Planet. As we descfinish right into the earth the temperature rises about 25 degrees Celsius for eincredibly kilometer that we descfinish. The deeper the layers are buried the hotter the temperatures end up being. The good weight of these layers also reasons a rise in push, which subsequently, reasons an increase in temperature.




The descending of rock layers at subduction areas reasons metamorphism in two ways; the shearing effect of the plates sliding past each various other reasons the rocks coming in call with the descfinishing rocks to readjust. Some of the descfinishing rock will certainly melt because of this friction. When rock melts it is then taken into consideration igneous not metamorphic, but the rock alongside the melted rock can be adjusted by the warm and also become a metamorphic rock. The diagram above mirrors you where metamorphic rock (YELLOW ZONE) can be created at a subduction zone.

There are 3 factors that reason a boost in press which likewise causes the development of metamorphic rocks. These factors are;


The huge weight of overlying layers of sediments.


Stresses led to by plates colliding in the process of hill structure.


Stresses led to by plates sliding past each other, such as the shearing stresses at the San Andreas fault zone in California.

Factors that cause chemical changes in rocks also contribute to the formation of metamorphic rocks. Very warm fluids and also vapors can, bereason of excessive pressures, fill the pores of existing rocks. These fluids and also vapors can cause chemical reactions to take location, that over time, deserve to change the chemical makeup of the parent rock.

Metamorphism have the right to be instantaneous as in the shearing of rocks at plate borders or have the right to take millions of years as in the slow-moving cooling of magma hidden deep under the surconfront of the Planet.


There are three means that metamorphic rocks can form. The 3 types of metamorphism are Contact, Regional, and also Dynamic metamorphism.

Contact Metamorphism occurs as soon as magma comes in contact through an already existing body of rock. When this happens the existing rocks temperature rises and also additionally becomes infiltrated with fluid from the magma. The area affected by the contact of magma is commonly little, from 1 to 10 kilometers. Contact metamorphism produces non-foliated (rocks without any kind of cleavage) rocks such as marble, quartzite, and hornfels.




In the diagram above magma has puburned its means into layers of limerock, quartz sandrock and also shale. The warmth generated by the magma chamber has readjusted these sedimentary rocks right into the metamorphic rocks marble, quartzite, an hornfels.

Regional Metamorphism occurs over a a lot bigger area. This metamorphism produces rocks such as gneiss and schist. Regional metamorphism is resulted in by large geologic processes such as mountain-structure. These rocks once exposed to the surface display the unbelievable press that cause the rocks to be bent and also damaged by the hill structure procedure. Regional metamorphism usually produces foliated rocks such as gneiss and schist.

Dynamic Metamorphism likewise occurs because of mountain-building. These huge forces of heat and push reason the rocks to be bent, folded, crushed, flattened, and sheared.


Metamorphic rocks are almost constantly harder than sedimentary rocks. They are mainly as hard and also occasionally harder than igneous rocks. They create the roots of many kind of mountain chains and also are exposed to the surface after the softer outer layers of rocks are eroded away. Many type of metamorphic rocks are discovered in mountainous areas now and also are a good indicator that ancient hills were present in areas that are now low hill or even flat levels. Metamorphic rocks are split right into 2 categories- Foliates and also Non-foliates.




Foliates are written of big quantities of micas and chlorites. These minerals have very unique cleavage. Foliated metamorphic rocks will certainly break-up along cleavage lines that are parallel to the minerals that consist of the rock. Slate, as an instance, will certainly break-up into thin sheets. Foliate comes from the Latin word that means sheets, as in the sheets of paper in a book.


Silt and also clay have the right to come to be deposited and also compressed into the sedimentary rock shale. The layers of shale have the right to come to be hidden deeper and deeper by the procedure of deposition. Deposition is the laying dvery own of rock developing product by any herbal agent (wind, water, glaciers) over time. Since these layers are buried, temperatures and also pressures become higher and higher until the shale is adjusted right into slate. Slate is a fine-grained metamorphic rock through perfect cleavage that enables it to split right into thin sheets. Slate usually has actually a light to dark brown streak. Slate is produced by low grade metamorphism, which is resulted in by fairly low temperatures and also pressures.




Slate has actually been supplied by man in a selection of ways over the years. One usage for slate was in the making of headstones or grave markers. Slate is not very tough and can be sculpted quickly. The trouble via slate though is its perfect cleavage. The slate headstones would crack and split alengthy these cleavage planes as water would certainly seep into the cracks and also freeze which would certainly result in development. This freeze-thaw, freeze-thaw over time would split the headrock. Today headstones are made of a selection of rocks, via granite and also marble being two of the many widely supplied rocks. Slate was additionally used for chalk boards. The babsence color was good as a background and the rock cleaned conveniently via water. Today it is not incredibly advantageous to usage this rock because of its weight and the splitting and cracking over time.



Schist is a tool grade metamorphic rock. This means that it has been subjected to more warmth and also push than slate, which is a low grade metamorphic rock. As you have the right to see in the photo over schist is a more coarse grained rock. The individual grains of minerals have the right to be checked out by the naked eye. Many type of of the original minerals have been changed right into flakes. Due to the fact that it has been squeezed harder than slate it is regularly uncovered folded and crumpled. Schists are usually called by the major minerals that they are developed from. Bitotite mica schist, hornblende schist, garnet mica schist, and talc schist are some examples of this.




Gneiss is a high grade metamorphic rock. This suggests that gneiss has actually been based on even more warmth and pressure than schist. Gneiss is coarser than schist and has actually distinct banding. This banding has actually alternating layers that are composed of various minerals. The minerals that write gneiss are the same as granite. Feldspar is the many important mineral that provides up gneiss along with mica and also quartz. Gneiss have the right to be developed from a sedimentary rock such as sandstone or shale, or it can be formed from the metamorphism of the igneouse rock grantite. Gneiss have the right to be used by male as paving and building rock.




Non-Foliates are metamorphic rocks that have actually no cleavage at all. Quartzite and also marble are two examples of non-foliates that we are going to examine.


Quartzite is written of sandrock that has been metamorphosed. Quartzite is much harder than the parent rock sandrock. It develops from sandstone that has come right into call via deeply hidden magmas. Quartzite looks comparable to its parent rock. The ideal means to tell quartzite from sandrock is to break the rocks. Sandrock will shatter into many type of individual grains of sand also while quartzite will break across the grains.



Marble is metamorphosed limerock or dolomite. Both limerock and dolomite have actually a huge concentration of calcium carbonate (CaCO3). Marble has actually many different sizes of crystals. Marble has actually many shade variances due to the impurities present at formation. Several of the different colors of marble are white, red, babsence, mottled and also banded, gray, pink, and also green.

Marble is much harder than its parent rock. This allows it to take a polish which renders it a good material for use as a structure material, making sink tops, bathtubs, and also a carving rock for artists. Today, headstones are made from marble and also granite bereason both of these rocks weather exceptionally gradually and also carve well through sharp edges.

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Marble is quarried in Vermont, Tenneswatch, Missouri, Georgia, and also Alabama.


Write the answers to the following inquiries in finish sentences on a piece of paper.