Weathering & Soil
•______& its effects
- ______processes that break down rock.
- Sediments: sand, silt, & ______
- Weathering ______the Earth’s surface.
•Mechanical Weathering
- Occurs when ______are broken apart by physical processes.
•Caused by:
- ______plants
- Burrowing ______
- ______ice
•Ice ______occurs where water enters cracks in rocks, freezes, & expands.
•As surface area increases, more rock is ______to be weathered.
•Chemical Weathering
- Chemicals ______the minerals in rocks or change them into different minerals.
- Naturally formed acids can weather rocks ______
- ______acid forms when Carbon dioxide mixes with water. The acid reacts with calcite in limestone to form caves.
- Some roots & ______plants give off acids that dissolve minerals in rock.
- ______occurs when some materials are exposed to oxygen and water. (Rust)
•Effects of Climate
- Mechanical weathering occurs more in ______climates.
- ______weathering occurs more in warm, wet climates.
- Rock type can affect the ______of weathering in a particular climate.
•Soil
•______of Soil
- Weathering gradually ______rocks into smaller and smaller fragments.
- Plants and animals add organic matter to the rock ______.
•Soil is a ______of
- Weathered ______
- Decayed ______matter
- ______fragments
- Water
- ______
•______for soil formation include:
- Climate
- ______
- Types of ______
- Types of vegetation
- Length of ______that rock has been weathering
•Composition of Soil
- Decayed organic matter turns into a dark-colored material called ______.
- Humus provides ______for plants.
- Burrowing creatures mix humus with the other ______fragments.
•Soil ______
•A ______(topsoil)
- Can be covered by litter,organic material that will eventually become humus and helps ______erosion.
•B Horizon
- ______in color & contains less humus.
- Leeching is the removal of minerals that have been ______by water.
- Water reacts with humus & carbon ______to form acid.
•C Horizon
- Made of partially weathered rock and is found at the ______of a soil profile.
•Soil Types
- Different types of ______vary in color, depth, texture, & fertility.
- The type of soil depends on the region’s ______.
- Deserts are dry, prairies are ______, & temperate forests are mild & moist.
•Soil ______
•Soil – An Important Resource
- Soil is eroded when it is moved to a new location by ______or water.
- Soil erosion removes ______that is important for plant growth.
•Causes and ______of Soil Erosion
- Human activities can ______therate of soil erosion.
- Soil erosion occurs rapidly on steep slopes and areas that are not covered by ______.
- Forest ______& overgrazing contribute to the rate at which erosion can occur.
•Preventing Soil Erosion
- Farmers reduce erosion by planting ______belts, using no-till farming, and planting cover crops after harvesting.
- Contour farming and terracing are used to control erosion on ______.
- Rows of trees (______) areplanted on the plains to reduce erosion caused by wind.
Erosional Forces
Erosion
•Wearing away of surface materials by ______, water, wind, or glaciers.
•______- process where sediments are dropped by erosion agents as they lose energy.
•Mass movement occurs as ______moves materials down a ______as one large mass.
Examples: Slumping, Creeping, Rock ______, & Mudflows
- Steep slopes can be made ______with vegetation, drainage pipes, and walls of concrete or railroad ties.
Glaciers
•Large masses of ice and ______that slowly move on land causing erosion.
•______- erosion process caused by moving glaciers picking up ______, gravel, & sand.
Scour & scrape the soil and ______
Grooves & ______indicate the direction a glacier moved.
•Glaciers ______a mixture of different sized sediments (till) when they retreat.
Moraine- a ridge, or ______, of deposit left at the end of a glacier.
Outwash- material deposited in layers by the ______of a glacier, with largest pieces closer to the glacier.
Eskers – ______deposit formed as meltwater rivers within the ice deposit sand & gravel within their channels.
•Types of Glaciers
Continental Glaciers-huge ______of ice and snow that cover large areas of land.
Covers 10% of Earth near the poles. (______& Greenland)
Ice Ages - periods of ______glaciation over the last 2 to 3 million yrs.
______than some mountain ranges.
______- exist in mountain ranges.
Cirques- bowl-shaped ______in the sides of mountains.
Arête- a long ______that forms when two valley glaciers ______a mountain side-by-side.
Peaks- form when valley glaciers erode a ______from several directions.
______formed by glaciers are “U” shaped
Wind
•Scatters dust or ______ash over thousands of kilometers.
•______- wind removes small particles of loose sediment, leaving behind heavier materials.
•Abrasion- wind behaves like a ______blowing sand grains against rocks ______them down.
•______– rows of trees planted to slow down wind in order to reduce erosion.
•Dunes – mounds of sediment ______by wind.
______Erosion
Surface Water
______
•Rainwater that doesn’t ______in to the ground or ______.
•Affected by:
Amount of ______
______of time it falls
Steepness, or ______, of the land
______of vegetation
Rivers & Streams
•River system –network of ______& streams that come together to form a system.
•Drainage Basin- area of land from which a stream or river collects ______
The ______River ______basin is the largest in the United States
______River
Flows swiftly through a ______valley.
May have ______& waterfalls.
______the bottom faster than the sides.
“V” shaped ______
______Stream
Flows ______through the valley.
Erodes more on the sides.
Forms ______& oxbow lakes.
Carves a flat, broad valley floor called a ______
______Stream
Flows smoothly through a ______it has carved.
Delta – fan shaped area formed by sediments that are ______as water empties into an ocean or lake.
______– fan shaped area formed by sediments that are deposited as water empties from a mountain valley onto a flat open plain.
Groundwater
•Groundwater is water that soaks into the ground and collects in the ______of the underlying soil.
•Soil and rock are ______if water can pass through the pore spaces. (Sandstone)
•Soil and rock are impermeable if water cannot pass through the pore spaces. (______)
•______– a layer of permeable rock that lets water move freely.
Zone of Saturation: area where all the ______are filled with water.
Water Table: upper ______of the zone of saturation.
•______are used to pump groundwater from an ______to the surface.
Artesian wells – wells that don’t require a pump because the water is under ______.
______– free flowing water because the water ______is so close to the surface.
Geyser – hot spring that erupts ______, shooting water & steam into the air.
•______are formed by Carbonic acid dissolving limestone rock, thereby enlarging cracks to form chambers.
Stalactites– Calcium ______deposits that hang from a cave’s ceiling.
______– Calcium carbonate deposits that form on a ______floor.
•Other Features:
______Straws
Cave ______
Cave Pearls
______
Columns
______Shoreline
•Shoreline Forces
Waves ______against pound against shores.
Currents move sediments along the ______.
______carry sediment out to sea & bring in new sediment.
•Rocky Shorelines
______& cliffs
•Sandy Beaches
Beaches –deposits of sediments ______to the shore.
______– fragile sand deposits that parallel the shore but are ______from the mainland.