1. Key Terms: weathering, mechanical weathering, chemical weathering, sediment, erosion, deposition, compaction, cementation.

2. Sediment Please turn to page 52 in your textbook. Sedimentary rocks form from sediment. Sediment is any small solid piece of material that come from : pre-existing rock broken down into smaller pieces remains of living things (organic material) such as shells, bones, leaves, dead wood, etc. crystallized dissolved minerals. Stop : Complete Formation of Sedimentary Rocks Activity Worksheet Number 1 Before Continuing 2

3. Weathering Weathering is the process that breaks down rock and other substances at Earth’s surface. The process of mountain building thrusts rock up to the Earth’s surface. There the rock becomes subject to weathering. There are two types of weathering Mechanical Weathering Chemical Weathering 3

4. Mechanical Weathering Mechanical weathering occurs when rock is broken down into smaller pieces by physical changes. The forces of mechanical weathering that breaks rock into pieces are Freezing and thawing (frost wedging) Release of pressure Growth of Plants Actions of animals Abrasion These forces are called the agents of mechanical weathering. 4

5. Chemical Weathering Chemical weathering occurs when rock is broken down through chemical changes. The agents of chemical weathering that break down rock are Water Oxygen Carbon dioxide Living organisms Acid Rain Stop : Complete Formation of Sedimentary Rocks Activity Worksheet Number 2, 3, and 4 Before Continuing 5

6. From Sediment to Rock Different processes occur in a specific order that turn sediment into sedimentary rock. Erosion- the movement of sediment. Deposition- the depositing of the sediment. Compaction- pressing the sediment together. Cementation- binding the sediment. 6

7. Erosion Erosion occurs when sediment is moved. Sediment can be moved by: Gravity Rivers and Streams Glaciers Wind Waves These are known as agents of erosion. Stop : Complete Formation of Sedimentary Rocks Activity Worksheet Number 5 Before Continuing

8. Deposition Deposition is the process by which sediment settles out of the agent of erosion that had been carrying it. Sediment is deposited in: Horizontal layers layers become very thick after a long periods of time. Oldest layers on the bottom Law of Superposition. 8

9. Erosion and Deposition Animation Observe how sediment is eroded and deposited Observe how sediment is eroded and deposited 9

10. Compaction After being deposited, thick layers of sediment build up. These layers are heavy and press down on the layers beneath them. Compaction then occurs. Compaction is the process that presses sediments together. 10

11. Cementation Minerals are dissolve in water. The water containing the dissolved minerals seep into the spaces between the sediment. The water evaporates, leaving behind the crystallized minerals. Cementation then occurs. Cementation is the process in which dissolved minerals crystallize and glue particles of sediment together. Often takes millions of years for compaction and cementation to transform loose sediments into solid sedimentary rock. 11

12. Compaction and Cementation Animation Observe how sediment is compacted and cemented. Observe how sediment is compacted and cemented Stop : Complete Formation of Sedimentary Rocks Activity Worksheet Number s 6 and 7 Before Continuing 12

13. Classifying Sedimentary Rock Geologists classify sedimentary rock according to the type of sediment that make up the rock. Clastic Sedimentary Rock Sediment type: Rock fragments Organic (Biochemical) Sedimentary Rock Sediment type: Remains of Biological/Organic material. Mainly fossil shells or plant fragments. Chemical Sedimentary Rock Sediment type: dissolved mineral crystallization. Mainly chemically precipitated crystals Stop: Complete Formation of Sedimentary Rocks Activity Worksheet Number 8 and turn in your activities sheet when finished. 13