Question | Answer |
What can the sand on a beach be part of? | A boulder |
For how many years can a boulder break down into many smaller pieces? | Millions |
What is the breakdown of rock material by physical and chemical processes called? | Weathering |
What are two kinds of weathering? | Physical and chemical |
What is it called when rocks get smaller and smaller without a change in the composition of the rock? | Physical change |
What is the process by which rock is broken down into smaller pieces by physical change called? | Physical weathering |
What are some agents of physical weathering? | Temperature changes, pressure changes, plant and animal actions, water, wind, and gravity |
When do materials become even more exposed to physical changes? | As they break apart |
How can changes in temperature cause a rock to break apart? | 1. A rise in temperature will cause the rock to expand
2. A decrease in temperature will cause a rock the contract
3. Repeated temperature changes can weaken the structure of a rock, causing the rock to crumble |
Even changes in temperature between ____ and ____ temperatures can be significant | Day, night |
What is the term used that can cause rock to physically break apart and is sometimes known as frost wedging? | Ice wedging |
How does ice wedging occur? | 1. When water collects in cracks in rocks and the temperature drops, the water may freeze
2. Water expands as it freezes to become ice
3. As ice expands, the crack will widen
4. As more water enters the crack, it can expand into and even larger size. |
What can cause even the largest of rocks to split apart? | A small crack |
What is pressure change? | 1. Rocks formed under pressure deep within the Earth become exposed at the surface
2. As overlying materials are removed above the rocks, pressure decreases
3. The rock expands, causing the outermost layers of rock to separate from the underlying layers |
What is exfoliation? | The process by which the outer layers of rock slowly peel away due to pressure changes |
When animals dig burrows into the ground which allows more rock to be exposed, what is this called? | Animal action |
What are some common burrowing animals? | Ground squirrels, prairie dogs, ants, and earthworms |
How do these animals allow materials to be exposed at the surface? | They move soils |
What is more likely to occur at the surface than below the surface? | Weathering |
What is the breaking down and weathering away of rock material by mechanical action of other rock | abrasion |