Earth's rocks

• What are the three main types of rocks?


  Sedimentary, igneous, and metamorphic
• What defines sedimentary rocks?


  • Formed by accumulation and compression of sediments
  • Can include fragments of other rocks, mineral deposits, and organic materials
  • Typically form in layers and can preserve fossils
• What is the process critical in creating sedimentary rocks?


  Compression of sediments
• What are the key stages in sedimentary rock formation?


  1. Weathering: Rocks break down into smaller particles
  2. Erosion: Particles are transported by water, wind, or ice
  3. Deposition: Particles settle in layers
  4. Compaction: Layers are squeezed together
  5. Cementation: Minerals crystallize between particles
• What happens during the weathering stage of sedimentary rock formation?


  Rocks break down into smaller particles
• What is the role of erosion in sedimentary rock formation?


  Particles are transported by natural forces
• What occurs during the deposition stage of sedimentary rock formation?


  Particles settle in layers
• What is compaction in sedimentary rock formation?


  Layers are squeezed together
• What is cementation in sedimentary rock formation?


  Minerals crystallize between sediment particles
• How does sand on a beach become sandstone?

  Through weathering, erosion, deposition, compaction, and cementation
• Which sedimentary rock is primarily formed from marine organism remains?


  Limestone
• What defines igneous rocks?


  • Formed from cooling and solidification of magma or lava
  • Created through volcanic processes
  • Can be intrusive (underground) or extrusive (above ground)
• What is the primary source of material for igneous rock formation?


  Magma or lava
• What is an example of an intrusive igneous rock?


  Granite
• What are examples of common metamorphic rocks?


  **Foliated Rocks**:

  • Slate
  • Schist
  • Gneiss

  
  

  **Non-Foliated Rocks**:

  • Marble
  • Quartzite
  • Hornfels
• What defines metamorphic rocks?


  • Transformed by intense heat, pressure, or both
  • Formed from existing rocks (sedimentary, igneous, or other metamorphic rocks)
  • Undergo physical and chemical changes
• What are the primary factors that cause rock metamorphosis?


  Heat and pressure
• What is the defining characteristic of obsidian?


  It has a smooth, glass-like appearance
• What is an example of an extrusive igneous rock?


  Basalt
• What is the definition of weathering?


  Weathering is breaking down rocks at Earth's surface
• How does weathering differ from erosion?


  Weathering breaks down rocks in place, erosion moves them
• What are the three main types of weathering?

  • Physical weathering
  • Chemical weathering
  • Biological weathering
• What is physical weathering?


  Mechanical breakdown of rocks without chemical change
• What is chemical weathering?


  Decomposition of rocks through chemical reactions
• What is an example of chemical weathering?


  Oxidation causing rust on rocks
• Give an example of physical weathering.


  Freeze-thaw cycles expanding rock cracks
• What is biological weathering?


  Breakdown of rocks caused by living organisms
• Provide an example of biological weathering.


  Plant roots growing and splitting rocks
• What are the processes involved in physical weathering?


  • Freeze-thaw cycles
  • Pressure release
  • Thermal expansion
• What happens during pressure release weathering?


  Rocks expand when overlying pressure is removed
• What occurs during freeze-thaw weathering?


  Water freezes and expands in rock cracks
• What is the role of thermal expansion in weathering?


  Temperature changes cause rocks to crack
• What are the processes involved in chemical weathering?


  • Oxidation
  • Hydrolysis
  • Carbonation
• What is oxidation in the context of weathering?


  Chemical reaction causing rust on iron-containing rocks
• How does hydrolysis contribute to weathering?


  Water reacts with minerals, altering their structure
• What is carbonation in weathering?


  Carbon dioxide in water forms carbonic acid
• What are the processes involved in biological weathering?


  • Plant root activity
  • Animal burrowing
• How do plant roots contribute to biological weathering?


  Roots grow into cracks and split rocks apart
• What is the impact of animal burrowing on rocks?


  Animals break down rocks through their movements
• What is the definition of erosion?


  Erosion is the movement of rock materials