1. Chapter 5 Erosion and Deposition
The Erosion-Deposition Process

2. Constructive vs. Destructive
Constructive process build up features on Earth’s surface
Lave erupting from a volcano hardens and forms new land on the area where lava falls.
Destructive process tear down features on Earth’s surface
Hurricane can wash part of a shoreline into the sea

3. Weathering The breakdown of rock. Is a destructive process
Chemical weathering which changes the mineral composition of rock
Mechanical (Physical) weathering breaks rock into smaller pieces without changing the composition
Is a destructive process
Weathering Agents-water, wind, and ice
Water can dissolve minerals in rocks
Wind can grind and polish rocks by blowing particles against them
Ice can break a rock apart as it expands

4. Erosion
The removal of weathered material from one location to another.
Agents of erosion-water, wind, glaciers, gravity

5. The Rate of Erosion
Factors that affect the rate of erosion include weather, climate, topo-graphy, and type of rock
Strong winds transport weathered rock more easily than gentle breeze
Weathered rock moves faster down a steep hill than a flat area
Erosion occurs faster on barren land than on land covered with vegitation
Rate of erosion sometimes depends on the type of rock
Weathering can break rocks into small or large pieces depending on the type of rock

6. Sorting Erosion affects level of sorting
The separating of items into groups according to one or more properties
Poorly sorted sediment, moderately sorted sediment, well-sorted sediment

7. Deposition
Constructive Process
Is the laying down or settling of eroded material

8. Depositional Environment
Sediments deposited in locations on land, along coast, or in other oceans
Swamps, deltas, beaches, barrier island, marshes, and the ocean floor
Environment where sediment is transported and deposited
High-energy environments (rushing rivers, ocean shores with large waves, and deserts with strong winds)
Low-energy environments (deep lakes and areas of slow-moving air or water)

9. Landforms Mountains, valleys, plains, sea cliffs, and beaches
Characteristics-structure, elevation, and rock exposure
Can be observed to determine whether destructive forces (erosion), constructive forces (deposition) produced landforms

10. Landforms Created by Erosion
Landforms can have features that are produced by erosion (often tall, jagged structure with cuts in layers of rock)
Landforms formed by erosion can expose several layers of rock
Different rates of erosion can result in unusual landforms when some rocks erode and leave more erosion-resistant rocks behind
Glacial erosion and coastal erosion form unique landforms

11. Landforms Created by Deposition
Landforms created by deposition are often flat and low-lying
Wind deposition form deserts of sand
Deposition also occurs where mountain streams reach the gentle slopes of wide, flat valleys
Alluvial Fan-an apron of sediment forms where a stream flows from a steep, narrow canyon onto a flat plain at the foot of a mountain

12. Landforms Created by Deposition cont’d
Water traveling in a river can slow due to friction with the edges and the bottom of the river channel
Deposition can form sandbar
Endpoint for most rivers in where they reach a lake or an ocean and deposit sediment
Wave action at a shoreline moves and deposit sediment