Waterfall formation

• What is the main topic of the discussion?

  Waterfall formation
• Why are there fewer waterfalls near the school?

  Because of the river's upper course conditions
• How many stages are there in waterfall formation?

  Four stages
• What are the two types of rock involved in waterfall formation?

  • More resistant rock (hard rock)
  • Less resistant rock (soft rock)
• What does "MR" stand for in the context of rock types?

  More resistant rock
• What does "LR" represent in the rock types?

  Less resistant rock
• What type of erosion occurs in the upper course of the river?

  Vertical erosion
• Where do waterfalls primarily occur in a river?

  In the upper course
• What causes waterfalls to form?

  Transition from more resistant to less resistant rock
• What happens to the less resistant rock during waterfall formation?

  It gets eroded by hydraulic action
• What is hydraulic action?

  The force of water eroding rock
• What is created as the less resistant rock is eroded?

  A plunge pool
• How does the velocity of water change as it flows over a step?

  It increases
• What effect does increased velocity have on hydraulic action?

  It causes rapid hydraulic action
• What happens to the more resistant rock over time?

  It becomes overhanging and eventually breaks
• What is a gorge?

  A steep-sided valley formed by erosion
• What happens to the collapsed material in a plunge pool?

  It gets eroded over time
• What are the four stages of waterfall formation?

  1. Initial formation with vertical erosion
  2. Erosion of less resistant rock by hydraulic action
  3. Creation of a plunge pool
  4. Retreat of the waterfall and formation of a gorge