Chapter 4 – Review Book Weathering, Erosion, and Deposition Define the Vocabulary 1. abrasion_____ ______________________________________________________________________ 2. agent of erosion _____________________________________________________________________ 3. bedrock__________ _________________________________________________________________ 4. chemical weathering__________________________________________________________________ 5. deposition__________________________________________________________________________ 6. discharge (stream)___________________________________________________________________ 7. erosion ____________________________________________________________________________ 8. frost action (frost wedging)____________________________________________________________ 9. glacial erractic_______________________________________________________________________ 10. graded bedding ____________________________________________________________________ 11. horizontal sorting ___________________________________________________________________ 12. mass movement (mass wasting)________________________________________________________ 13. meander __________________________________________________________________________ 14. outcrop ___________________________________________________________________________ 15. physical weathering_________________________________________________________________ 16. precipitate_________________________________________________________________________ 17. residual soil________________________________________________________________________ 18. sediment__________________________________________________________________________ 19. soil ______________________________________________________________________________ 20. soil horizon ________________________________________________________________________ 21. solution __________________________________________________________________________ 22. sorted ____________________________________________________________________________ 23. stream velocity _____________________________________________________________________ 24. striation __________________________________________________________________________ 25. suspension ________________________________________________________________________ 26. till_______________________________________________________________________________ 27. transported soil ____________________________________________________________________ 28. unsorted deposit____________________________________________________________________ 29. vertical sorting_____________________________________________________________________ 30. weathering ________________________________________________________________________ Answer the following questions based on the reading: WHY DO ROCKS WEATHER? 1. When an outcrop of bedrock is brought to earth’s surface because of uplift, how does exposure to the wind, water and biological processes change the bedrock? __________________________________ _____________________________________________________________________________________ PHYSICAL WEATHERING 2. How does physical weathering change the size of rocks? ____________________________________ _____________________________________________________________________________________ a. Does the mineral composition change? __________________________________________________ 3. What type of climate is frost action the most important agent of physical weathering? ____________ _____________________________________________________________________________________ 4. What happens when water freezes in the cracks of rocks? ___________________________________ _____________________________________________________________________________________ 5. Why do the temperatures have to alternate between freezing and thawing for frost action to do its work? _______________________________________________________________________________ _____________________________________________________________________________________ 6. How do plant roots physically weather rock? ______________________________________________ _____________________________________________________________________________________ 7. When rock particles rub against each other and wear away, it is called abrasion. What are the 5 major agents of abrasion? _______________________________________________________________ _____________________________________________________________________________________ 8. In general, what types of minerals undergo physical weathering much easier? ___________________ _____________________________________________________________________________________ CHEMICAL WEATHERING 9. For the most part, minerals remain unchanged deep in Earth’s crust, but when they are uplifted they are exposed to the __________________________ and ___________________________. 10. What is the most important difference between chemical weathering and physical weathering? ___ _____________________________________________________________________________________ 11. What is the relationship between exposed surface area and the amount of chemical weathering? _____________________________________________________________________________________ 12. The rusting (oxidation) of iron is an example of chemical weathering. How does iron oxide (AKA rust) form?____________________________________________________________________________ 13. What happens to feldspars when they are exposed at Earth’s surface? ________________________ _____________________________________________________________________________________ 14. Chemical weathering usually requires __________________________________________________ 15. What type of climate is chemical weathering dominant? ___________________________________ _____________________________________________________________________________________ 16. Why is quartz found in sediments but olivine is not? _______________________________________ _____________________________________________________________________________________ 17. Limestone and marble contain calcite. Explain the process that is responsible for the weathering of calcite? ______________________________________________________________________________ _____________________________________________________________________________________ HOW DO SOILS FORM? 18. Under natural conditions, biological, physical and chemical weathering develops soils. How? a. physical weathering __________________________________________________________________ b. chemical weathering__________________________________________________________________ c. biological processes __________________________________________________________________ 19. Layers of soil (horizons) develop in soils that stay in place and are not moved from above the bedrock (residual soils). Using figure 4-5., discuss the soil horizons of the mature soil. A is composed of _______________________________________________________________________ B is __________________________________________________________________________________ C is __________________________________________________________________________________ 20. The top layer is usually dark and very fertile because it has organic material called ______________ 21. Most soils are not fully developed because they have been transported by erosion. Most of New York State is covered by soil that came from the _____________ and was deposited by ______________ 22. In New York State, which layer(s) is/are missing in the transported soil? _______________________ PROTECTING THE SOIL 23. Discuss at least 2 ways that soil gets destroyed. a. ___________________________________________________________________________________ b. ___________________________________________________________________________________ HOW ARE WEATHERED MATERIALS TRANSPORTED? 24. What is the underlying force of all erosion? ______________________________________________ 25. What is talus and where does it accumulate? ____________________________________________ EROSION BY GRAVITY ACTING ALONE 26. Gravity alone can cause sediment to move downhill but if _____________ is added to the sediment it makes mass movement more likely. 27. The different types of mass movement are: a. ___________________________________________________________________________________ b.___________________________________________________________________________________ c. ___________________________________________________________________________________ EROSION OF WATER 28. Running water in streams and rivers in the world is the most important erosional agent. 29. Running water transports sediments in several ways. Discuss how sediment is moved. a. Solution ____________________________________________________________________________ b, Suspension__________________________________________________________________________ c. Flotation ___________________________________________________________________________ 30. Some sediment is too big to be carried by the stream and rolls along the bottom of the stream. What is the relationship between size of sediment and the velocity of the water? ___________________ _____________________________________________________________________________________ VELOCITY OF STREAMS 31. Explain the 2 factors control the speed or velocity of the stream? a. ___________________________________________________________________________________ b. ___________________________________________________________________________________ 32. Describe the area of the stream where the water flows fastest and explain why_________________ _____________________________________________________________________________________ 33. Broad, flat valleys develop meanders which are bends in the stream. Describe the velocities of water as is flows along the bend. _________________________________________________________ _____________________________________________________________________________________ 34. Figure 4-10 shows water flowing around a meander. Circle the correct term - The fastest water is on the (inside or outside) of the bend causing (erosion or deposition); the slowest water is on the (inside or outside) of the stream causing (erosion or deposition). EROSION BY WIND 35. What particles can wind pick up and move? ______________________________________________ _____________________________________________________________________________________ 36. Where does wind erosion usually occur? ________________________________________________ _____________________________________________________________________________________ EROSION BY ICE 37. How does a glacier that forms in high latitude and high altitude locations move sediment? ________ _____________________________________________________________________________________ 38. How does a glacier act like a “huge abrasion system”? _____________________________________ _____________________________________________________________________________________ 39. Circle one. Streams erode valleys into (V-shape or U-shape) and glaciers erode these valleys into (Vshape or U-shape). Use Figure 4-11 to help you understand. 40. Glaciers are called “rivers of ice” but they move much slower than streams but what is one way they are like streams? _______________________________________________________________________ _____________________________________________________________________________________ CHARACTERISTIC CHANGES CAUSED BY AGENTS OF EROSION 41. Each agent of erosion causes unique changes to sediment. Describe the characteristics of each erosional agent on sediment or rock. Figure 4-12 can help you distinguish the properties. Gravity Running water Glacial Ice Wind (Mass Movement) Characteristics WHAT IS DEPOSITION? 42. What happens during deposition or sedimentation? _______________________________________ _____________________________________________________________________________________ FACTORS THAT AFFECT DEPOSITION: SIZE, SHAPE, DENSITY OF PARTICLES PARTICLE SIZE 43. What is the relationship between size of particle and the rate of deposition? ___________________ _____________________________________________________________________________________ 44. What is the relationship between density and the rate of deposition? _________________________ _____________________________________________________________________________________ 45. What is the relationship between settling rate and settling time? ____________________________ _____________________________________________________________________________________ SORTING OF SEDIMENTS 46. Why does deposition happen? ________________________________________________________ _____________________________________________________________________________________ 47. What is the pattern of deposition when a stream enters a large body of water like an ocean – what gets deposited first/last? ________________________________________________________________ _____________________________________________________________________________________ 48. Horizontal sorting happens when stream’s velocity slows down gradually. Vertical sorting happens when different size particles settle in calm water. Graded Bedding is a type of vertical sorting that shows several distinct periods of deposition. Using figures 4-13, 4-14 and 4-15 draw the 2 different sorting arrangements. HORIZONTAL SORTING VERTICAL SORTING/GRADED BEDDING DEPOSITION BY GRAVITY 49. Circle the correct answer. When gravity acts alone the sediment/talus are (round, angular) and the sediment/talus is (sorted, unsorted). DEPOSITION IN WATER 50. Water sorts sediment. Why does a delta form when a stream enters a lake or ocean? ___________ _____________________________________________________________________________________ DEPOSITION BY WIND 51. Why does wind generally only carry fine sediment? _______________________________________ _____________________________________________________________________________________ 52. Figure 4-16 shows how sand dunes form. Prevailing winds are winds that blow consistently in the same direction forming a windward side which is (gentle, steep) and a leeward side which is (gentle, steep). Be able to identify the prevailing winds by using a sand dune diagram. In the diagram below the winds are blowing (right to left, left to right). DEPOSITION BY GLACIERS 53. If the glacier deposited the sediment it will be (sorted, unsorted) and if meltwater coming from the glacier deposited the sediment it will be (sorted, unsorted). 54. What are 2 ways a glacial erratic is different from other large rocks? __________________________ _____________________________________________________________________________________ _____________________________________________________________________________________