Igneous Rocks Essay

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Igneous rocks are formed from the ejection of earth’s volcanoes. Deep down inside earth’s mantle there lies hot magma. Magma is molten rock that is kept below the surface. This mixture is usually made up of four parts: a hot liquid substance which is called the melt; minerals that have been crystallized by the melt; solid rocks that have made themselves tangled in the melt because of loose materials, and finally gases that have become liquid. Magma is created by an increase in temperatures, pressure change, and a alter in composition. When this magma is ejected from earth’s crust it earns a new name called lava. The lava hardens and becomes an Igneous rock.
There are two types of Igneous rocks. The first is intrusive, which is when the magma slowly cools beneath the earths surface. Because the magma is cooling slowly it allows the rocks end result to form crystal- like pigments. Examples of intrusive igneous rocks are Diorite, Gabbro, Granite, Pegmatite, and Periodotite. All of these rocks are course and grainy. The other type is an extrusive Igneous rock. This lava erupts onto the surface of the earth and cools rapidly also forming crystals, the lava cools so fast that at times it allows the rocks to form as clear-like glass. Examples of these rocks are Andesite, Basalt, Obsidian, Pumice, Rhyolite, Scoria, …show more content…

They are mostly created under water. Sediment makes up a sedimentary rock with materials such as mud, clay, sand, pebbles, and organisms that once lived. These materials are worn away over years by natural occurrences such as wind, water, rain, and snow. Imagine a road in the winter when it begins breaking apart and withering away. The sediment eventually ends up in one place and layer upon each other. When observing these rocks we get the opportunity to see into the past and understand how the world was like long ago. This is possible by observing the impressions made by different organisms and

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