Rock Classification SEDIMENTARY ROCKS, IGNEOUS ROCKS, AND METAMORPHIC ROCKS

Sedimentary rocks are unique rocks that form and are found in places that are unlike a lot of other rock types. Sedimentary rocks form when deposition and burial lead to compaction and cementation. Sedimentary rocks can be found in fossils because, the processes that make types of rocks other than sedimentary would destroy fossils. There are 3 different types of sedimentary rocks that form from different minerals and in different environments.
This is a clastic sedimentary rock known as conglomerate.

One of the 3 types of sedimentary rocks is inorganic. Otherwise, known as clastic. Clastic is another word to describe fragments. The way sedimentary clastic rocks hold together is through natural cementing agents. Clastic rocks seem to form in layers and in fossils. Some good examples of clastic rocks are conglomerate, breccia, sandstone, siltstone, and shale. Clastic rocks cement together when sediments are compressed and cemented underground, and then stay together with the help of natural cementing agents, like the ones I mentioned earlier.

This map shows where geographic features are in relation to where clastic rocks form.

This map gives a detailed example of where you can generally find clastic rocks. It shows what vicinities generally house clastic rock deposits. Like, whether or not they form near rivers, or the shore or ponds, or rivers.

This is limestone, a chemical, sedimentary rock.

Another one of the types of sedimentary rocks is crystalline rocks. Otherwise, known as chemical rocks. When mineral constituents become super saturated and unnaturally precipitate, they form chemical rocks. Chemical rocks include rock salt, rock gypsum, dolostone, limestone, halite, sylvite, and barite. One example of how these kinds of rocks form, is how limestone forms by having its calcite (what it is made of) precipitated out of the water because the ocean can't hold any more of it. Then, when it is precipitated, it changes form into limestone.

All of the locations where chemical rocks are mined, are near water, showing the dependence on water to precipitate minerals into chemical sedimentary rocks.

This map shows data of where various precipitate chemicals are. The places shown are mines that were chosen because of having a high chemical precipitate concentration, hence why they are shown on this chemical data map.

This is an image of bituminous coal, which is an organic sedimentary rock formed because of pressure.

The third type of sedimentary rock is the organic rock. One key separation between organic rocks are the other 2 types of sedimentary rocks is that organic rocks are made of previously living things. Usually, it is just shells and bones that are cemented together. Limestone forms from this as well. While, limestone can be formed chemically, it can also be formed organically. Dead plants are another thing that can transform into organic rocks. The way dead things such as roots, plants, shells, and bones become organic rocks is through compaction, and pressure that solidification.

This map shows the concentration of organic sedimentary rocks in the U.S.

The way this map works is, the lighter green has the deepest concentration and the dark green has the lowest, and the red and blue fall in between. This shows the concentration of how much of any given organic rock is in various places in America, and how deep it goes. Swamps are a key place where organics rocks form because of the abundance of dead plant life, which and buried and solidified through pressure.

This is from page 10 of the ESRT and is the Rock Cycle in Earth's Crust.

The section of the cycle that involves sedimentary rocks is the section in between sediments and sedimentary rocks. The way it works is, sediments go through deposition and/or burial which, compacts and/or cements them and eventually the pressure forms a sedimentary rock.

This is granite, an intrusive igneous rock.

The second type of rock, other than sedimentary is igneous. There are 2 types of igneous rocks. There are the intrusive igneous rocks and the extrusive igneous rocks, which each form in slightly different ways from one another. They form in different ways, and cool at different rates, altering the resulting appearance of the igneous rocks based on which type it is.

This is diorite. Diorite is one of the intrusive igneous rocks.

Intrusive igneous rocks crystallize below the earth's surface. They cool at a slow pace, and that's why they allow large crystals to form. Some examples of these types of igneous rocks are diorite, gabbro, granite, pegmatite, and peridotite. These kinds of rocks form while being under the pressure that comes along with being underground.

This is basalt, it is an extrusive igneous rock.

The way extrusive igneous rocks form differently from intrusive igneous rocks, is that they erupt onto the surface, whether than cool underground. They generally cool a lot faster in comparison to intrusive igneous rocks, and can form a glassy texture as a result. Some examples of these kinds of rocks are, andesite, obsidian, basalt, pumice, rhyolite, scoria, and tuff.

This is a map of how and where the 2 types of igneous rocks form.

This map shows how while, the intrusive rocks form below the surface under different variables, extrusive rocks form above ground, with unlike variations.

The area of the cycle in between metamorphic rock and igneous rock describes the path an igneous rock takes.

Igneous rocks melt into magma and solidify into igneous rocks.

This is gneiss, it is a foliated metamorphic rock.

The third and final type of rock, other than sedimentary and igneous, is metamorphic. Metamorphic rocks can form in one of two ways. A metamorphic rock can be foliated or non-foliated. Each type of metamorphic rock has an altered appearance.

Slate, is a foliated metamorphic rock.

Any foliated metamorphic rock is subject to the appearance of layering or banding. This means you can see the separate layers and or band lines on the rock. This is caused by exposure to heat and direct pressure. Some examples of foliated metamorphic rocks are gneiss, slate, schist, and phyllite.

This is a marble rock. Marble rocks are non-foliated metamorphic rocks.

They do not form with any visible effects from heat and or pressure. According to this, they do not have layering or banding. This makes them different from foliated metamorphic rocks. Examples include hornfels, marble, quartzite, and novaculite. The pressure and heat for non-foliated rocks is generally more than that of foliated rocks, and rather than band or layer like foliated rocks, it uses the pressure to compact itself and slowly crystallize.

This map shows how and where you can find various metamorphic rocks.

There is a key and information that can show you the different metamorphic rocks and roughly where they are found within the area showed in the map.

The area of the cycle in between sedimentary rock and metamorphic rock is the cycle a metamorphic rock takes.

A metamorphic rock forms by heating and being putting a sedimentary rock under pressure, changing into a metamorphic rock.

Credits:

Created with images by Steve Snodgrass - "Curvy Rock (Sedimentary)" • James St. John - "Siltstone" • James St. John - "Conglomerate"

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