Rocks

• What are the three types of rock?

  Igneous, metamorphic, and sedimentary
• What type of rock will be concentrated on in this video?

  Sedimentary rocks
• Name three examples of sedimentary rocks.

  Conglomerate, mudstone, and limestone
• How are sedimentary rocks formed?

  By minerals settling in layers
• What is the first process in forming sedimentary rocks?

  Weathering
• What is sediment?

  Small pieces of broken rock
• What is biological weathering?

  Weathering by living organisms
• How do plants contribute to biological weathering?

  By breaking up rocks with their roots
• What is chemical weathering?

  Weathering caused by chemical reactions
• How does acid rain contribute to weathering?

  It chemically breaks down rocks over time
• What is physical weathering?

  Weathering due to physical changes
• Give an example of physical weathering.

  Water or sand bashing into rocks
• What is freeze-thaw weathering?

  Water freezes in rock cracks, expanding
• Where does freeze-thaw weathering commonly occur?

  On cliff edges and roads
• What is transportation in the context of sedimentary rock formation?

  Movement of sediments by wind or water
• What are the three types of rock?

  Igneous, metamorphic, and sedimentary
• What do we call the combined processes of weathering and transportation?

  Erosion
• What happens during deposition?

  sediments settle in layers
• What are the characteristics of igneous rocks?

  • Made up of interlocking crystals
  • Non-porous (water can't enter)
  • Formed from volcanic activity
• Where do sediments often settle?

  At the bottom of the ocean
• What are examples of igneous rock?

  Granite, basalt, and obsidian
• What is compaction in sedimentary rock formation?

  Weight of sediments squashes them together
• What is molten rock outside a volcano called?

  Lava
• What is molten rock inside a volcano called?

  Magma
• What is cementation?

  Layers of sediments stick together
• How do igneous rocks form?

  • From lava cooling outside the volcano (extrusive)
  • From magma cooling underground (intrusive)
• What is a key characteristic of sedimentary rock?

  Visible layers of sediment
• What are extrusive igneous rocks?

  Rocks formed from lava cooling outside the volcano
• Why do sedimentary rocks often contain fossils?

  Dead marine organisms settle among layers
• What are intrusive igneous rocks?

  Rocks formed from magma cooling underground
• What are the main processes involved in forming sedimentary rocks?

  1. Weathering: Breaking down of large rocks

  • Biological, chemical, and physical weathering

  1. Transportation: Movement of sediments

  • By wind or water

  1. Deposition: Settling of sediments in layers
  2. Compaction: Weight squashes sediments together
  3. Cementation: Sediments stick together to form rock
• Why do extrusive igneous rocks have small crystals?

  They cool quickly, allowing little time for crystals
• What is basalt used for?

  Building and construction
• What are the types of weathering and their characteristics?

  • Biological Weathering: Caused by living organisms
  • Chemical Weathering: Caused by chemical reactions (e.g., acid rain)
  • Physical Weathering: Caused by physical changes (e.g., freeze-thaw)
• Why do intrusive igneous rocks have large crystals?

  They cool slowly, allowing time for crystals
• What is granite used for?

  Kitchen worktops
• What is the significance of sedimentary rocks in geology?

  • Formed from sediments settling in layers
  • Often contain fossils
  • Provide insights into Earth's history
• What are the conditions needed to form metamorphic rocks?

  • Heat
  • Pressure
• What are examples of metamorphic rocks?

  Nice, schist, and slate
• How do metamorphic rocks form?

  From sedimentary and igneous rocks undergoing heat and pressure