Sedimentary and Metamorphic Rocks. Chapter 3.3nd 3.4 The Earth’s Surface. I. Sedimentary Rock- This type of rock forms from sediments. Sediments - are materials that settle out of water and air. They are usually created by weathering and erosion from wind or moving water. .
Chapter 3.3nd 3.4
The Earth’s Surface
There are four types of sediments that can be found on earth. These sediments are arranged by their size.
1.Gravel 2.Sand 3.Silt 4.Clay
2. Cementation- This occurs when minerals crystallize around sediments, cementing them together. These types of rocks can form as water evaporates, or over long periods of time as minerals collect between sediments.
Coal is formed as the remains of prehistoric plants compressed under the weight of the ground.
Limestone forms as coral, shells, plankton and other remains from sea life are cemented or pressed together.
Metamorphic Rocks- When rocks are put under heat and pressure over time, they undergo metamorphism. Metamorphism means to change into something new.
2. Nonfoliated Rock- These rocks tend to form when the parent rock is made mostly of one mineral and usually in small areas with lots of heat. ( example: Quartzite)