Types of Rocks: Igneous, Metamorphic, and Sedimentary PDF

1. There are 3 types of rocks (Igneous, metamorphic, sedimentary) Igneous rocks are formed to relation to volcanoes, Igneous rocks are "fire-born," meaning that they are formed from the cooling and solidification of molten (melted) rock. The word igneous derives from ignis, the Lat...

1. There are 3 types of rocks (Igneous, metamorphic, sedimentary) Igneous rocks are formed to relation to volcanoes, Igneous rocks are "fire-born," meaning that they are formed from the cooling and solidification of molten (melted) rock. The word igneous derives from ignis, the Latin word for "fire." Molten rock material is known as magma until it is erupted onto the surface when it then is termed lava There are 2 types of igneous rocks, Intrusive and extrusive, extrusive rocks form on the surface through larva, they have a quicker formation rate and therefore, less crystals, while intrusive rocks are formed below the earths crust and have a longer formation rate with more crystals. Igneous rocks do not include fossil deposits as whenever fossils are deep in the earths crust, it erupts out to the surface and is destroyed by the sheer heat these rocks produce. Although, most igneous rocks contain more than one mineral deposit, these minerals are available in the form of patches of different sizes. Igneous rocks are generally glassy or course and usually do not react to acids. 2. There are two types of weathering, physical weathering, which breaks rocks into smaller pieces without changing its composition, and chemical weathering, which changes the rocks composition. There are a few types of physical weathering such as temperature change(freeze), water finds its way into small cracks in the rock and as the water freezes it expands causing the rock to break apart. There is also Temperature change (onion skin), during the day sun heats up the surface of rocks causing it to expand, then, at night the rock cools and contracts, when repeated, the rock will crack and break. Lastly, there is biological weathering, seeds may fall into the cracks of rocks and as the plant grows, the roots wedge the rock apart. Then there is chemical weathering, acid rain, rain is slightly acidic due to it being mixed with carbon dioxide, this new substance can break down and weaken rocks. 3. Weathering and erosion can lead to the formation of sediments, sediments, when put through a process, can form sedimentary rocks. The process goes like this... step 1. Deposition, sediment , dead animals, and plant material settle to the bottom of oceans and lakes in horizontal layers. Step 2. Compaction, over millions of years, the sediment grains are squashed together by the weight of of layers above built over thousands of years. Step 3. Cementation, as the grains are squeezed tightly together solutions containing minerals, such as gypsum, between the grains precipitate and cement the grains together to form sedimentary rocks. Sedimentary rocks form in layers known as scrata, inn these rocks, fossils can be present. There are 3 types of sedimentary rocks, Clastic, formed by compaction and cementation of rock sediment, Organic, formed by compaction and cementation of dead organic material, and chemical, formed when water transports and re-deposits material. 4. Metamorphic rocks are formed when existing rocks are exposed to immence heat and pressure resulting in a different rocks with different properties. There are 2 types of metamorphism, Regional and contact metamorphism. Regional metamorphism forms slowly, over millions of years and over large areas, the rocks are put under immence heat and pressure as rocks are buried under other rock layers. Regional metamorphism, though, occurs when molten rock, magma or larva rises and comes into contact with surrounding rocks, in this scenario, there is more heat than pressure.