1. 3.5 – Sedimentary Rocks  Essential Questions: 1. How Do Sedimentary Rocks Form? 2. What Are the Three Major Types of Sedimentary Rocks? 3. How Are Sedimentary Rocks Used?

2. How Do Sedimentary Rocks Form?  Most sedimentary rocks are formed through a sequence of processes: weathering, erosion, deposition, compaction, and cementation.

3. How Do Sedimentary Rocks Form?  Sediment is small, solid pieces of material that come from rocks or living things.

4. How Do Sedimentary Rocks Form?  Weathering is the breaking up of rock on Earth’s surface through freezing and thawing, plant roots, acid, or other forces.

5. How Do Sedimentary Rocks Form?  Erosion is the movement of these pieces by wind, water, gravity, or ice (glaciers) from one place to another.

6. How Do Sedimentary Rocks Form?  Deposition is the process by which sediments settle out the water or wind carrying it.

7. How Do Sedimentary Rocks Form?  After many layers of sediments have been laid down squeezing older sediments together, the older rocks become compacted.

8. How Do Sedimentary Rocks Form?  While compaction is taking place, some minerals in the rock slowly dissolve in the water. Cementation is the process in which dissolved minerals crystallize and glue particles of sediment together.

9. What Are the Three Major Types of Sedimentary Rocks?  Different processes form the three different types of sedimentary rocks.  Clastic Rocks  Organic Rocks  Chemical Rocks

10. Clastic Rocks  Formed when rock fragments are squeezed together.  Microscopic to boulder-sized. Clastic rocks are classified by fragment size.

11. Organic Rocks  Formed from the remains of once living things.  Limestone and Coal

12. Chemical Rocks  Formed when minerals dissolved in a water solution crystallize or when shallow sea or lakes evaporate.  Halite (Rock Salt) Halite – Rock Salt

13. How Are Sedimentary Rocks Used?  Throughout history sedimentary rocks have been used for tools and building materials.  Sandstone buildings and monuments.  Flint tools and weapons.