1. The rock cycle
By: Lauren Billman

2. How Were the earth’s rocks formed?
There are three types of rocks on Earth called Sedimentary, Igneous, and Metamorphic. Each type of rock was formed in a slightly different way.

3. Sedimentary Rocks
Three quarters of earths rocks are sedimentary rocks. They form near lakes, oceans, and rivers. These rocks are formed from sediment, which is found in mud, rocks, sand, and even dust. One type of rock, called Clastic sedimentary Rocks, are formed from little pieces of broken rock from other rocks. Over time, they might join together to create one big rock. Another type of sedimentary rock is Chemical Sedimentary Rock. These rocks are not formed from broken pieces from other rocks, but are made through a chemical process. These rocks are made of halite and gypsum. The last type of sedimentary rocks are Organic Sedimentary Rocks. These rocks are made of remnants of things from the Earth, such as dinosaur bones, plants, and clamshells. Sedimentary rocks are important because they show scientists how the earth has evolved and changed over time. Fossils can also be found in sedimentary rock, which shows scientists creatures, plants, and animals that used to live on Earth. This is what sedimentary rocks are.

4. Igneous Rocks
When molten rock cools and turns hard, Igneous rocks are formed. Molten rocks are called lava when they are above Earth’s surface, and is called Magma when it’s below Earth’s surface. Because of this, there are two groups of igneous rocks. One group is called Intrusive Igneous Rocks. These type of rocks are made when magma cools very slowly, and makes rocks with filled crystals. Another type of igneous rock is called Extrusive Igneous Rocks. These are formed when lava goes on Earth’s surface, and cools. This process happens relatively quickly. Granite is actually a form of igneous rock, and granite is used to make countertops. These are the different types of igneous rocks.

5. Metamorphic Rocks
Any type of rock can become a metamorphic rock. Rocks become metamorphic rock deep underneath Earth’s surface, in a very hot environment with high pressure. There are also tectonic plates under the surface of the Earth that collide with each other in order to create metamorphic rocks. Some metamorphic rocks are foliated, while others are not. Foliation occurs when minerals are organized at a right angle towards the pressure. However, metamorphic rocks don’t always need to be foliated. Metamorphism can be classified in two categories: contact metamorphism and regional metamorphism. Contact metamorphism is when the rocks touch magnum or lava. Depending on how much magma is present producing heat, will effect how much the rock changes. Regional metamorphism is happens when parts of the layer on Earth’s surface collide and the rock changes. Some of the areas that the rocks are metamorphosed over can be as large as states, or countries. Metamorphic Rocks undergo lots of changes.

6. Works cited
"Rock and the Rock Cycle." Windows To The Universe. The National Earth Science Teachers Association, Web. 24 Aug <
Smith, Rene. "Metamorphic Rock Facts." Science Kids. Science Kids, Aug Web. 24 Aug <http%3A%2F%2Fwww.sciencekids.co.nz%2Fsciencefacts%2Fearth%2Fmetamorphicrocks .html>.