Types of Rocks

 Brianna Sullivan

Mrs.Troster

English 8 – Classification

7 April 2017

Types of rocks

            Did you know that sedimentary rocks are formed from eroded fragments of other rocks or even from the remains of plants or animals? Did you know when igneous rocks cool crystals begin to form on the rock? Did you know slate is a type of metamorphic rock, and it’s formed when sedimentary or igneous rocks are exposed to conditions of very high pressure or temperature? These are only some of the interesting facts about rocks. There are several types of rocks, but sedimentary, metamorphic, and igneous will be discussed in this essay.

            First of all, sedimentary is formed by weathering and erosion Transported to the place of deposition by water, wind, ice mass movement or glaciers. Sedimentary has weathering which happens and makes rocks wear away. Erosion has the process of with wind or water to make the rock break apart. The sedimentary rock has transported of deposition which involves water, wind, ice mass movement or glacier. The rock is then moved to a different area.

            Next metamorphic is change in form has a physical and chemical change. Metamorphic rock has the change in form it can goes through a rotation with igneous and sedimentary which changes its form. It makes up a large part of the earth’s crust and twelve percent of the earth current land surface. With the change in temperatures within the rock. It has temperature that’s greater than one hundred fifty to two hundred degrees Celsius. The rock is subjected to high temperatures and great pressure of the rock layers above it.

            Finally Igneous which is formed by cooling and solidification of magma. It has increase in temperature, a decrease in pressure and a change in composition. During the rotation between the three types of rocks igneous goes through a stage of cooling and solidification. In this stage the rock cools and begins to form and become hard. There is also the increase in temperature, decrease in pressure and composition. The temperature changes a lot during the rocks rotation it can go from being really hot to be really cold. The rocks each have different stages for them to be able to form. The decrease in pressure depends on how the temperature is.  There is composition this is very important for the rock because this is the mixture of the type of rock being created and how it is made.

To sum up the three types of rocks goes through many stages to be created and each have a different way of forming all types of rocks. There are several types of rocks, which are sedimentary, metamorphic, and igneous will be discussed in this essay.