How are Metamorphic Rocks formed?
A metamorphic rock is formed out
of igneous or sedimentary rocks that have been put under immense pressure and heat that the rock is crushed and is very compacted.
Examples of these types of rocks are Gneiss and Schist.
How are Sedimentary Rocks formed?
Sedimentary rocks are formed by erosion.
The wind and rain erode little bits of the Earth. The little bits get washed to the bottom of rivers or lakes or the ocean. After many layers begin to form on the bottom of lakes or oceans, the bottom layers start to turn to rock because of the weight and pressure put on the bottom. Examples are Shale, Gypsum and Limestone and many more.
Sources
Peyton, Tammy. "Discover How Rocks Are Formed." Discover How Rocks Are Formed. Franklin Institute, 8 Aug. 1998. Web. 25 Apr. 2013.
How is an Igneous rock formed?
How are rocks formed?
- Igneous rocks are also known as "Fire Rocks"
- They are called Fire Rocks because these
rocks are formed by cooling magma.
-Extrusive Igneous rocks are formed by
when a volcano erupts and the magma
comes up as lava, once the lava is on the
surface, it cools and turns to an igneous rock.
- Intrusive rocks are formed by when melted magma does not move for a while, the magma starts to create air bubbles in which these crystals are created. Examples: Granite and Obsidian.