1. SEDIMENTARY ROCKS
Unit 1: Sixth Grade

2. How sedimentary rocks form…
Wind, water, ice, sunlight, and gravity cause rocks to weather into sediments.
These sediments are moved from one location to another by the process of erosion.
Erosion: The movement of the material from one place to another

3. Formation of Sedimentary Rocks
The sediments are eventually deposited on to older layers and form new ones.
The sediments become compacted and dissolved minerals separate from water and form a natural cement—Lithification.
Sedimentary rocks are formed

4. Strata and stratification
Layers of rock
STRATIFICATION
process in which sedimentary rocks are arranged in layers

5. How are were the stripes formed?
Wind blew over thousands of years
Carried mineral/rock fragments, “sand” to ocean floors, lakes rivers
The sand mixes with quartz or calcite.
Pressure over time causes them to become rock

6. How are the Stripes Formed?
But not all sand is the same!
Over millions of years, smaller grains separated from the larger grains and were layered on the bottome

7. Petra Why do you think there are so many colors in the stone?
Can you describe the pattern on this structure?
Does this structure support the idea that layers of sediments piled on top of each other and exposed to heat and pressure form sedimentary rock?

8. Organic sedimentary rocks
Form from remains or fossils of once living things.
EXAMPLE: limestone, coal
COAL----
Forms underground when partially decomposed plant material is buried beneath sediment and is changed into coal the pressure from layers above.
This process takes millions for years.
Non-renewable fossil fuel

10. Clastic sedimentary rocks
Made from fragments (sediments) of rocks that are cemented together by minerals .
They are classified according to the size of the fragments.
EXAMPLES: conglomerate, sandstone, siltstone, shale

11. Loose sediments
Clastic Sedimentary Rock

12. Chemical sedimentary rocks
Form from solutions of dissolved minerals and water.
EXAMPLE: halite